diff --git a/.github/scripts/docker/Dockerfile b/.github/scripts/docker/Dockerfile
index 15f49f8264..94e8d8e1e3 100644
--- a/.github/scripts/docker/Dockerfile
+++ b/.github/scripts/docker/Dockerfile
@@ -31,12 +31,15 @@ LABEL github_repo="https://github.com/k2-fsa/icefall"
 
 # Install dependencies
 RUN pip install --no-cache-dir \
-      torch==${TORCH_VERSION} torchaudio==${TORCHAUDIO_VERSION} -f https://download.pytorch.org/whl/cpu/torch_stable.html \
+      torch==${TORCH_VERSION}+cpu -f https://download.pytorch.org/whl/torch \
+      torchaudio==${TORCHAUDIO_VERSION}+cpu -f https://download.pytorch.org/whl/torchaudio \
       k2==${_K2_VERSION} -f https://k2-fsa.github.io/k2/cpu.html \
       \
       git+https://github.com/lhotse-speech/lhotse \
       kaldifeat==${_KALDIFEAT_VERSION} -f https://csukuangfj.github.io/kaldifeat/cpu.html \
+      conformer==0.3.2 \
       cython \
+      diffusers \
       dill \
       espnet_tts_frontend \
       graphviz \
@@ -45,10 +48,11 @@ RUN pip install --no-cache-dir \
       kaldialign \
       kaldifst \
       kaldilm \
+      librosa \
       matplotlib \
       multi_quantization \
       numba \
-      numpy \
+      "numpy<2.0" \
       onnxoptimizer \
       onnxsim \
       onnx \
diff --git a/.github/scripts/docker/generate_build_matrix.py b/.github/scripts/docker/generate_build_matrix.py
index 08281151ee..9c53a38df8 100755
--- a/.github/scripts/docker/generate_build_matrix.py
+++ b/.github/scripts/docker/generate_build_matrix.py
@@ -43,9 +43,11 @@ def get_torchaudio_version(torch_version):
 
 
 def get_matrix():
-    k2_version = "1.24.4.dev20240223"
-    kaldifeat_version = "1.25.4.dev20240223"
-    version = "20240905"
+    k2_version = "1.24.4.dev20241029"
+    kaldifeat_version = "1.25.5.dev20241029"
+    version = "20241029"
+
+    # torchaudio 2.5.0 does not support python 3.13
     python_version = ["3.8", "3.9", "3.10", "3.11", "3.12"]
     torch_version = []
     #  torch_version += ["1.13.0", "1.13.1"]
@@ -56,6 +58,7 @@ def get_matrix():
     torch_version += ["2.3.0", "2.3.1"]
     torch_version += ["2.4.0"]
     torch_version += ["2.4.1"]
+    torch_version += ["2.5.0"]
 
     matrix = []
     for p in python_version:
@@ -69,25 +72,16 @@ def get_matrix():
             if version_gt(p, "3.11") and not version_gt(t, "2.1"):
                 continue
 
+            if version_gt(p, "3.12") and not version_gt(t, "2.4"):
+                continue
+
+            if version_gt(t, "2.4") and version_gt("3.10", p):
+                # torch>=2.5 requires python 3.10
+                continue
+
             k2_version_2 = k2_version
             kaldifeat_version_2 = kaldifeat_version
 
-            if t == "2.2.2":
-                k2_version_2 = "1.24.4.dev20240328"
-                kaldifeat_version_2 = "1.25.4.dev20240329"
-            elif t == "2.3.0":
-                k2_version_2 = "1.24.4.dev20240425"
-                kaldifeat_version_2 = "1.25.4.dev20240425"
-            elif t == "2.3.1":
-                k2_version_2 = "1.24.4.dev20240606"
-                kaldifeat_version_2 = "1.25.4.dev20240606"
-            elif t == "2.4.0":
-                k2_version_2 = "1.24.4.dev20240725"
-                kaldifeat_version_2 = "1.25.4.dev20240725"
-            elif t == "2.4.1":
-                k2_version_2 = "1.24.4.dev20240905"
-                kaldifeat_version_2 = "1.25.4.dev20240905"
-
             matrix.append(
                 {
                     "k2-version": k2_version_2,
diff --git a/.github/scripts/ljspeech/TTS/run-matcha.sh b/.github/scripts/ljspeech/TTS/run-matcha.sh
new file mode 100755
index 0000000000..37e1bc3204
--- /dev/null
+++ b/.github/scripts/ljspeech/TTS/run-matcha.sh
@@ -0,0 +1,120 @@
+#!/usr/bin/env bash
+
+set -ex
+
+apt-get update
+apt-get install -y sox
+
+python3 -m pip install piper_phonemize -f https://k2-fsa.github.io/icefall/piper_phonemize.html
+python3 -m pip install espnet_tts_frontend
+python3 -m pip install numba conformer==0.3.2 diffusers librosa
+
+log() {
+  # This function is from espnet
+  local fname=${BASH_SOURCE[1]##*/}
+  echo -e "$(date '+%Y-%m-%d %H:%M:%S') (${fname}:${BASH_LINENO[0]}:${FUNCNAME[1]}) $*"
+}
+
+cd egs/ljspeech/TTS
+
+sed -i.bak s/600/8/g ./prepare.sh
+sed -i.bak s/"first 100"/"first 3"/g ./prepare.sh
+sed -i.bak s/500/5/g ./prepare.sh
+git diff
+
+function prepare_data() {
+  # We have created a subset of the data for testing
+  #
+  mkdir -p download
+  pushd download
+  wget -q https://huggingface.co/csukuangfj/ljspeech-subset-for-ci-test/resolve/main/LJSpeech-1.1.tar.bz2
+  tar xvf LJSpeech-1.1.tar.bz2
+  popd
+
+  ./prepare.sh
+  tree .
+}
+
+function train() {
+  pushd ./matcha
+  sed -i.bak s/1500/3/g ./train.py
+  git diff .
+  popd
+
+  ./matcha/train.py \
+    --exp-dir matcha/exp \
+    --num-epochs 1 \
+    --save-every-n 1 \
+    --num-buckets 2 \
+    --tokens data/tokens.txt \
+    --max-duration 20
+
+    ls -lh matcha/exp
+}
+
+function infer() {
+
+  curl -SL -O https://github.com/csukuangfj/models/raw/refs/heads/master/hifigan/generator_v1
+
+  ./matcha/inference.py \
+    --epoch 1 \
+    --exp-dir ./matcha/exp \
+    --tokens data/tokens.txt \
+    --vocoder ./generator_v1 \
+    --input-text "how are you doing?" \
+    --output-wav ./generated.wav
+
+  ls -lh *.wav
+  soxi ./generated.wav
+  rm -v ./generated.wav
+  rm -v generator_v1
+}
+
+function export_onnx() {
+  pushd matcha/exp
+  curl -SL -O https://huggingface.co/csukuangfj/icefall-tts-ljspeech-matcha-en-2024-10-28/resolve/main/exp/epoch-4000.pt
+  popd
+
+  pushd data/fbank
+  rm -v *.json
+  curl -SL -O https://huggingface.co/csukuangfj/icefall-tts-ljspeech-matcha-en-2024-10-28/resolve/main/data/cmvn.json
+  popd
+
+  ./matcha/export_onnx.py \
+    --exp-dir ./matcha/exp \
+    --epoch 4000 \
+    --tokens ./data/tokens.txt \
+    --cmvn ./data/fbank/cmvn.json
+
+  ls -lh *.onnx
+
+  if false; then
+    # THe CI machine does not have enough memory to run it
+    #
+    curl -SL -O https://github.com/csukuangfj/models/raw/refs/heads/master/hifigan/generator_v1
+    curl -SL -O https://github.com/csukuangfj/models/raw/refs/heads/master/hifigan/generator_v2
+    curl -SL -O https://github.com/csukuangfj/models/raw/refs/heads/master/hifigan/generator_v3
+    python3 ./matcha/export_onnx_hifigan.py
+  else
+    curl -SL -O https://huggingface.co/csukuangfj/icefall-tts-ljspeech-matcha-en-2024-10-28/resolve/main/exp/hifigan_v1.onnx
+  fi
+
+  ls -lh *.onnx
+
+  python3 ./matcha/onnx_pretrained.py \
+   --acoustic-model ./model-steps-6.onnx \
+   --vocoder ./hifigan_v1.onnx \
+   --tokens ./data/tokens.txt \
+   --input-text "how are you doing?" \
+   --output-wav /icefall/generated-matcha-tts-steps-6-v1.wav
+
+  ls -lh /icefall/*.wav
+  soxi /icefall/generated-matcha-tts-steps-6-v1.wav
+}
+
+prepare_data
+train
+infer
+export_onnx
+
+rm -rfv generator_v* matcha/exp
diff --git a/.github/scripts/ljspeech/TTS/run.sh b/.github/scripts/ljspeech/TTS/run.sh
index 707361782f..733a12c47b 100755
--- a/.github/scripts/ljspeech/TTS/run.sh
+++ b/.github/scripts/ljspeech/TTS/run.sh
@@ -22,7 +22,7 @@ git diff
 function prepare_data() {
   # We have created a subset of the data for testing
   #
-  mkdir download
+  mkdir -p download
   pushd download
   wget -q https://huggingface.co/csukuangfj/ljspeech-subset-for-ci-test/resolve/main/LJSpeech-1.1.tar.bz2
   tar xvf LJSpeech-1.1.tar.bz2
diff --git a/.github/scripts/run-gigaspeech-pruned-transducer-stateless2-2022-05-12.sh b/.github/scripts/run-gigaspeech-pruned-transducer-stateless2-2022-05-12.sh
index c9e798a68d..8d98fca1ee 100755
--- a/.github/scripts/run-gigaspeech-pruned-transducer-stateless2-2022-05-12.sh
+++ b/.github/scripts/run-gigaspeech-pruned-transducer-stateless2-2022-05-12.sh
@@ -19,7 +19,7 @@ repo=$(basename $repo_url)
 
 echo "GITHUB_EVENT_NAME: ${GITHUB_EVENT_NAME}"
 echo "GITHUB_EVENT_LABEL_NAME: ${GITHUB_EVENT_LABEL_NAME}"
-if [[ x"${GITHUB_EVENT_NAME}" == x"schedule" || x"${GITHUB_EVENT_LABEL_NAME}" == x"run-decode"  ]]; then
+if [[ x"${GITHUB_EVENT_NAME}" == x"schedule" || x"${GITHUB_EVENT_NAME}" == x"workflow_dispatch" || x"${GITHUB_EVENT_LABEL_NAME}" == x"run-decode"  ]]; then
   mkdir -p pruned_transducer_stateless2/exp
   ln -s $PWD/$repo/exp/pretrained-iter-3488000-avg-20.pt pruned_transducer_stateless2/exp/epoch-999.pt
   ln -s $PWD/$repo/data/lang_bpe_500 data/
@@ -29,8 +29,16 @@ if [[ x"${GITHUB_EVENT_NAME}" == x"schedule" || x"${GITHUB_EVENT_LABEL_NAME}" ==
   ls -lh data/fbank
   ls -lh pruned_transducer_stateless2/exp
 
-  ln -sf data/fbank/cuts_DEV.jsonl.gz data/fbank/gigaspeech_cuts_DEV.jsonl.gz
-  ln -sf data/fbank/cuts_TEST.jsonl.gz data/fbank/gigaspeech_cuts_TEST.jsonl.gz
+  pushd data/fbank
+  curl -SL -O https://huggingface.co/csukuangfj/giga-dev-dataset-fbank/resolve/main/data/fbank/cuts_DEV.jsonl.gz
+  curl -SL -O https://huggingface.co/csukuangfj/giga-dev-dataset-fbank/resolve/main/data/fbank/cuts_TEST.jsonl.gz
+  curl -SL -O https://huggingface.co/csukuangfj/giga-dev-dataset-fbank/resolve/main/data/fbank/feats_DEV.lca
+  curl -SL -O https://huggingface.co/csukuangfj/giga-dev-dataset-fbank/resolve/main/data/fbank/feats_TEST.lca
+
+  ln -sf cuts_DEV.jsonl.gz gigaspeech_cuts_DEV.jsonl.gz
+  ln -sf cuts_TEST.jsonl.gz gigaspeech_cuts_TEST.jsonl.gz
+  popd
+
 
   log "Decoding dev and test"
 
diff --git a/.github/scripts/run-gigaspeech-zipformer-2023-10-17.sh b/.github/scripts/run-gigaspeech-zipformer-2023-10-17.sh
index 329896ef64..438edd3b1d 100755
--- a/.github/scripts/run-gigaspeech-zipformer-2023-10-17.sh
+++ b/.github/scripts/run-gigaspeech-zipformer-2023-10-17.sh
@@ -129,20 +129,34 @@ done
 
 echo "GITHUB_EVENT_NAME: ${GITHUB_EVENT_NAME}"
 echo "GITHUB_EVENT_LABEL_NAME: ${GITHUB_EVENT_LABEL_NAME}"
-if [[ x"${GITHUB_EVENT_NAME}" == x"schedule" || x"${GITHUB_EVENT_LABEL_NAME}" == x"run-decode"  ]]; then
+if [[ x"${GITHUB_EVENT_NAME}" == x"schedule" || x"${GITHUB_EVENT_NAME}" == x"workflow_dispatch" || x"${GITHUB_EVENT_LABEL_NAME}" == x"run-decode"  ]]; then
   mkdir -p zipformer/exp
   ln -s $PWD/$repo/exp/pretrained.pt zipformer/exp/epoch-30.pt
+  mkdir -p data
   ln -s $PWD/$repo/data/lang_bpe_500 data/
 
   ls -lh data
   ls -lh zipformer/exp
 
+  mkdir -p data/fbank
+  pushd data/fbank
+
+  curl -SL -O https://huggingface.co/csukuangfj/giga-dev-dataset-fbank/resolve/main/data/fbank/cuts_DEV.jsonl.gz
+  curl -SL -O https://huggingface.co/csukuangfj/giga-dev-dataset-fbank/resolve/main/data/fbank/cuts_TEST.jsonl.gz
+  curl -SL -O https://huggingface.co/csukuangfj/giga-dev-dataset-fbank/resolve/main/data/fbank/feats_DEV.lca
+  curl -SL -O https://huggingface.co/csukuangfj/giga-dev-dataset-fbank/resolve/main/data/fbank/feats_TEST.lca
+
+  ln -sf cuts_DEV.jsonl.gz gigaspeech_cuts_DEV.jsonl.gz
+  ln -sf cuts_TEST.jsonl.gz gigaspeech_cuts_TEST.jsonl.gz
+
+  popd
+
   log "Decoding test-clean and test-other"
 
   # use a small value for decoding with CPU
   max_duration=100
 
-  for method in greedy_search fast_beam_search modified_beam_search; do
+  for method in greedy_search; do
     log "Decoding with $method"
 
     ./zipformer/decode.py \
diff --git a/.github/scripts/run-librispeech-lstm-transducer-stateless2-2022-09-03.sh b/.github/scripts/run-librispeech-lstm-transducer-stateless2-2022-09-03.sh
index d547bdd450..8f5a8dbb93 100755
--- a/.github/scripts/run-librispeech-lstm-transducer-stateless2-2022-09-03.sh
+++ b/.github/scripts/run-librispeech-lstm-transducer-stateless2-2022-09-03.sh
@@ -162,7 +162,7 @@ if [[ x"${GITHUB_EVENT_LABEL_NAME}" == x"LODR" ]]; then
     --ngram-lm-scale -0.16
 fi
 
-if [[ x"${GITHUB_EVENT_NAME}" == x"schedule" ]]; then
+if [[ x"${GITHUB_EVENT_NAME}" == x"schedule" || x"${GITHUB_EVENT_NAME}" == x"workflow_dispatch" ]]; then
   mkdir -p lstm_transducer_stateless2/exp
   ln -s $PWD/$repo/exp/pretrained.pt lstm_transducer_stateless2/exp/epoch-999.pt
   ln -s $PWD/$repo/data/lang_bpe_500 data/
@@ -175,7 +175,7 @@ if [[ x"${GITHUB_EVENT_NAME}" == x"schedule" ]]; then
   # use a small value for decoding with CPU
   max_duration=100
 
-  for method in greedy_search fast_beam_search modified_beam_search; do
+  for method in greedy_search fast_beam_search; do
     log "Decoding with $method"
 
     ./lstm_transducer_stateless2/decode.py \
diff --git a/.github/workflows/audioset.yml b/.github/workflows/audioset.yml
index 280ef8f8e4..9c9446239e 100644
--- a/.github/workflows/audioset.yml
+++ b/.github/workflows/audioset.yml
@@ -83,7 +83,7 @@ jobs:
           ls -lh ./model-onnx/*
 
       - name: Upload model to huggingface
-        if: matrix.python-version == '3.9' && matrix.torch-version == '2.2.0' && github.event_name == 'push'
+        if: matrix.python-version == '3.9' && matrix.torch-version == '2.3.0' && github.event_name == 'push'
         env:
           HF_TOKEN: ${{ secrets.HF_TOKEN }}
         uses: nick-fields/retry@v3
@@ -116,7 +116,7 @@ jobs:
             rm -rf huggingface
 
       - name: Prepare for release
-        if: matrix.python-version == '3.9' && matrix.torch-version == '2.2.0' && github.event_name == 'push'
+        if: matrix.python-version == '3.9' && matrix.torch-version == '2.3.0' && github.event_name == 'push'
         shell: bash
         run: |
           d=sherpa-onnx-zipformer-audio-tagging-2024-04-09
@@ -125,7 +125,7 @@ jobs:
           ls -lh
 
       - name: Release exported onnx models
-        if: matrix.python-version == '3.9' && matrix.torch-version == '2.2.0' && github.event_name == 'push'
+        if: matrix.python-version == '3.9' && matrix.torch-version == '2.3.0' && github.event_name == 'push'
         uses: svenstaro/upload-release-action@v2
         with:
           file_glob: true
diff --git a/.github/workflows/ljspeech.yml b/.github/workflows/ljspeech.yml
index e202d21b58..7dca96b37e 100644
--- a/.github/workflows/ljspeech.yml
+++ b/.github/workflows/ljspeech.yml
@@ -70,6 +70,7 @@ jobs:
               cd /icefall
               git config --global --add safe.directory /icefall
 
+              .github/scripts/ljspeech/TTS/run-matcha.sh
               .github/scripts/ljspeech/TTS/run.sh
 
       - name: display files
@@ -78,19 +79,13 @@ jobs:
           ls -lh
 
       - uses: actions/upload-artifact@v4
-        if: matrix.python-version == '3.9' && matrix.torch-version == '2.2.0'
+        if: matrix.python-version == '3.9' && matrix.torch-version == '2.3.0'
         with:
           name: generated-test-files-${{ matrix.python-version }}-${{ matrix.torch-version }}
           path: ./*.wav
 
-      - uses: actions/upload-artifact@v4
-        if: matrix.python-version == '3.9' && matrix.torch-version == '2.2.0'
-        with:
-          name: generated-models-py${{ matrix.python-version }}-torch${{ matrix.torch-version }}
-          path: ./*.wav
-
       - name: Release exported onnx models
-        if: matrix.python-version == '3.9' && matrix.torch-version == '2.2.0' && github.event_name == 'push'
+        if: matrix.python-version == '3.9' && matrix.torch-version == '2.3.0' && github.event_name == 'push'
         uses: svenstaro/upload-release-action@v2
         with:
           file_glob: true
@@ -99,4 +94,3 @@ jobs:
           repo_name: k2-fsa/sherpa-onnx
           repo_token: ${{ secrets.UPLOAD_GH_SHERPA_ONNX_TOKEN }}
           tag: tts-models
-
diff --git a/.github/workflows/run-gigaspeech-2022-05-13.yml b/.github/workflows/run-gigaspeech-2022-05-13.yml
index 2c1d44fbfe..9fd05d94a0 100644
--- a/.github/workflows/run-gigaspeech-2022-05-13.yml
+++ b/.github/workflows/run-gigaspeech-2022-05-13.yml
@@ -41,7 +41,7 @@ concurrency:
 
 jobs:
   run_gigaspeech_2022_05_13:
-    if: github.event.label.name == 'ready' || github.event.label.name == 'run-decode' || github.event_name == 'push' || github.event_name == 'schedule'
+    if: github.event_name == 'workflow_dispatch' || github.event.label.name == 'ready' || github.event.label.name == 'run-decode' || github.event_name == 'push' || github.event_name == 'schedule'
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
@@ -106,7 +106,7 @@ jobs:
           .github/scripts/run-gigaspeech-pruned-transducer-stateless2-2022-05-12.sh
 
       - name: Display decoding results for gigaspeech pruned_transducer_stateless2
-        if: github.event_name == 'schedule' || github.event.label.name == 'run-decode'
+        if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch' || github.event.label.name == 'run-decode'
         shell: bash
         run: |
           cd egs/gigaspeech/ASR/
@@ -122,7 +122,7 @@ jobs:
 
       - name: Upload decoding results for gigaspeech pruned_transducer_stateless2
         uses: actions/upload-artifact@v4
-        if: github.event_name == 'schedule' || github.event.label.name == 'run-decode'
+        if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch' || github.event.label.name == 'run-decode'
         with:
           name: torch-${{ matrix.torch }}-python-${{ matrix.python-version }}-ubuntu-latest-cpu-gigaspeech-pruned_transducer_stateless2-2022-05-12
           path: egs/gigaspeech/ASR/pruned_transducer_stateless2/exp/
diff --git a/.github/workflows/run-gigaspeech-zipformer-2023-10-17.yml b/.github/workflows/run-gigaspeech-zipformer-2023-10-17.yml
index 4ecc2aea04..48322e75c0 100644
--- a/.github/workflows/run-gigaspeech-zipformer-2023-10-17.yml
+++ b/.github/workflows/run-gigaspeech-zipformer-2023-10-17.yml
@@ -90,10 +90,6 @@ jobs:
           GITHUB_EVENT_LABEL_NAME: ${{ github.event.label.name }}
           HF_TOKEN: ${{ secrets.HF_TOKEN }}
         run: |
-          mkdir -p egs/gigaspeech/ASR/data
-          ln -sfv ~/tmp/fbank-libri egs/gigaspeech/ASR/data/fbank
-          ls -lh egs/gigaspeech/ASR/data/*
-
           sudo apt-get -qq install git-lfs tree
           export PYTHONPATH=$PWD:$PYTHONPATH
           export PYTHONPATH=~/tmp/kaldifeat/kaldifeat/python:$PYTHONPATH
@@ -112,7 +108,7 @@ jobs:
           tag: asr-models
 
       - name: Display decoding results for gigaspeech zipformer
-        if: github.event_name == 'schedule' || github.event.label.name == 'run-decode'
+        if: github.event_name == 'schedule' || github.event.label.name == 'run-decode' || github.event_name == 'workflow_dispatch'
         shell: bash
         run: |
           cd egs/gigaspeech/ASR/
@@ -124,17 +120,17 @@ jobs:
           find exp/greedy_search -name "log-*" -exec grep -n --color "best for test-clean" {} + | sort -n -k2
           find exp/greedy_search -name "log-*" -exec grep -n --color "best for test-other" {} + | sort -n -k2
 
-          echo "===fast_beam_search==="
-          find exp/fast_beam_search -name "log-*" -exec grep -n --color "best for test-clean" {} + | sort -n -k2
-          find exp/fast_beam_search -name "log-*" -exec grep -n --color "best for test-other" {} + | sort -n -k2
-
-          echo "===modified beam search==="
-          find exp/modified_beam_search -name "log-*" -exec grep -n --color "best for test-clean" {} + | sort -n -k2
-          find exp/modified_beam_search -name "log-*" -exec grep -n --color "best for test-other" {} + | sort -n -k2
+          # echo "===fast_beam_search==="
+          # find exp/fast_beam_search -name "log-*" -exec grep -n --color "best for test-clean" {} + | sort -n -k2
+          # find exp/fast_beam_search -name "log-*" -exec grep -n --color "best for test-other" {} + | sort -n -k2
+          #
+          # echo "===modified beam search==="
+          # find exp/modified_beam_search -name "log-*" -exec grep -n --color "best for test-clean" {} + | sort -n -k2
+          # find exp/modified_beam_search -name "log-*" -exec grep -n --color "best for test-other" {} + | sort -n -k2
 
       - name: Upload decoding results for gigaspeech zipformer
         uses: actions/upload-artifact@v4
-        if: github.event_name == 'schedule' || github.event.label.name == 'run-decode'
+        if: github.event_name == 'schedule' || github.event.label.name == 'run-decode' || github.event_name == 'workflow_dispatch'
         with:
           name: torch-${{ matrix.torch }}-python-${{ matrix.python-version }}-ubuntu-latest-cpu-zipformer-2022-11-11
           path: egs/gigaspeech/ASR/zipformer/exp/
diff --git a/.github/workflows/run-librispeech-lstm-transducer-stateless2-2022-09-03.yml b/.github/workflows/run-librispeech-lstm-transducer-stateless2-2022-09-03.yml
index 6a3f4eb40a..1b222da2d4 100644
--- a/.github/workflows/run-librispeech-lstm-transducer-stateless2-2022-09-03.yml
+++ b/.github/workflows/run-librispeech-lstm-transducer-stateless2-2022-09-03.yml
@@ -24,7 +24,7 @@ concurrency:
 
 jobs:
   run_librispeech_lstm_transducer_stateless2_2022_09_03:
-    if: github.event.label.name == 'ready' || github.event.label.name == 'LODR' || github.event.label.name == 'shallow-fusion' || github.event_name == 'push' || github.event_name == 'schedule'
+    if: github.event.label.name == 'ready' || github.event.label.name == 'LODR' || github.event.label.name == 'shallow-fusion' || github.event_name == 'push' || github.event_name == 'schedule' || github.event_name == 'workflow_dispatch'
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
@@ -116,7 +116,7 @@ jobs:
           .github/scripts/run-librispeech-lstm-transducer-stateless2-2022-09-03.sh
 
       - name: Display decoding results for lstm_transducer_stateless2
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch'
         shell: bash
         run: |
           cd egs/librispeech/ASR
@@ -130,9 +130,9 @@ jobs:
           find fast_beam_search -name "log-*" -exec grep -n --color "best for test-clean" {} + | sort -n -k2
           find fast_beam_search -name "log-*" -exec grep -n --color "best for test-other" {} + | sort -n -k2
 
-          echo "===modified beam search==="
-          find modified_beam_search -name "log-*" -exec grep -n --color "best for test-clean" {} + | sort -n -k2
-          find modified_beam_search -name "log-*" -exec grep -n --color "best for test-other" {} + | sort -n -k2
+          # echo "===modified beam search==="
+          # find modified_beam_search -name "log-*" -exec grep -n --color "best for test-clean" {} + | sort -n -k2
+          # find modified_beam_search -name "log-*" -exec grep -n --color "best for test-other" {} + | sort -n -k2
 
       - name: Display decoding results for lstm_transducer_stateless2
         if: github.event.label.name == 'shallow-fusion'
@@ -159,7 +159,7 @@ jobs:
 
       - name: Upload decoding results for lstm_transducer_stateless2
         uses: actions/upload-artifact@v4
-        if: github.event_name == 'schedule' || github.event.label.name == 'shallow-fusion' || github.event.label.name == 'LODR'
+        if: github.event_name == 'schedule' || github.event.label.name == 'shallow-fusion' || github.event.label.name == 'LODR' || github.event_name == 'workflow_dispatch'
         with:
           name: torch-${{ matrix.torch }}-python-${{ matrix.python-version }}-ubuntu-latest-cpu-lstm_transducer_stateless2-2022-09-03
           path: egs/librispeech/ASR/lstm_transducer_stateless2/exp/
diff --git a/.github/workflows/yesno.yml b/.github/workflows/yesno.yml
index de822b33f6..a9d65516f1 100644
--- a/.github/workflows/yesno.yml
+++ b/.github/workflows/yesno.yml
@@ -61,5 +61,6 @@ jobs:
 
               python3 -m torch.utils.collect_env
               python3 -m k2.version
+              pip list
 
               .github/scripts/yesno/ASR/run.sh
diff --git a/egs/gigaspeech/ASR/pruned_transducer_stateless2/decode.py b/egs/gigaspeech/ASR/pruned_transducer_stateless2/decode.py
index ef430302df..f1efebcb94 100755
--- a/egs/gigaspeech/ASR/pruned_transducer_stateless2/decode.py
+++ b/egs/gigaspeech/ASR/pruned_transducer_stateless2/decode.py
@@ -260,7 +260,7 @@ def decode_one_batch(
       Return the decoding result. See above description for the format of
       the returned dict.
     """
-    device = model.device
+    device = next(model.parameters()).device
     feature = batch["inputs"]
     assert feature.ndim == 3
 
diff --git a/egs/libriheavy/ASR/local/prepare_manifest.py b/egs/libriheavy/ASR/local/prepare_manifest.py
index d7e184d863..a57a3749d2 100755
--- a/egs/libriheavy/ASR/local/prepare_manifest.py
+++ b/egs/libriheavy/ASR/local/prepare_manifest.py
@@ -20,6 +20,8 @@
 import sys
 from pathlib import Path
 
+from icefall.utils import str2bool
+
 
 def simple_cleanup(text: str) -> str:
     table = str.maketrans("’‘，。；？！（）：-《》、“”【】", "'',.;?!(): <>/\"\"[]")
@@ -34,7 +36,7 @@ def main():
     ), "Usage: ./local/prepare_manifest.py INPUT OUTPUT_DIR KEEP_CUSTOM_FIELDS"
     fname = Path(sys.argv[1]).name
     oname = Path(sys.argv[2]) / fname
-    keep_custom_fields = bool(sys.argv[3])
+    keep_custom_fields = str2bool(sys.argv[3])
     with gzip.open(sys.argv[1], "r") as fin, gzip.open(oname, "w") as fout:
         for line in fin:
             cut = json.loads(line)
diff --git a/egs/librispeech/ASR/RESULTS.md b/egs/librispeech/ASR/RESULTS.md
index 6a669f072d..e5a82dfda2 100644
--- a/egs/librispeech/ASR/RESULTS.md
+++ b/egs/librispeech/ASR/RESULTS.md
@@ -153,6 +153,7 @@ You can use <https://github.com/k2-fsa/sherpa> to deploy it.
 | decoding method                      | test-clean | test-other | comment             |
 |--------------------------------------|------------|------------|---------------------|
 | ctc-greedy-decoding                  | 2.57       | 5.95       | --epoch 50 --avg 25 |
+| ctc-prefix-beam-search               | 2.52       | 5.85       | --epoch 50 --avg 25 |
 
 The training command using 2 32G-V100 GPUs is:
 ```bash
@@ -184,7 +185,7 @@ export CUDA_VISIBLE_DEVICES="0,1"
 The decoding command is:
 ```bash
 export CUDA_VISIBLE_DEVICES="0"
-for m in ctc-greedy-search; do
+for m in ctc-greedy-search ctc-prefix-beam-search; do
   ./zipformer/ctc_decode.py \
     --epoch 50 \
     --avg 25 \
@@ -212,6 +213,7 @@ You can use <https://github.com/k2-fsa/sherpa> to deploy it.
 | decoding method                      | test-clean | test-other | comment             |
 |--------------------------------------|------------|------------|---------------------|
 | ctc-greedy-decoding                  | 2.12       | 4.62       | --epoch 50 --avg 24 |
+| ctc-prefix-beam-search               | 2.1        | 4.61       | --epoch 50 --avg 24 |
 
 The training command using 4 32G-V100 GPUs is:
 ```bash
@@ -238,7 +240,7 @@ export CUDA_VISIBLE_DEVICES="0,1,2,3"
 The decoding command is:
 ```bash
 export CUDA_VISIBLE_DEVICES="0"
-for m in ctc-greedy-search; do
+for m in ctc-greedy-search ctc-prefix-beam-search; do
   ./zipformer/ctc_decode.py \
     --epoch 50 \
     --avg 24 \
@@ -262,6 +264,7 @@ You can use <https://github.com/k2-fsa/sherpa> to deploy it.
 | decoding method                      | test-clean | test-other | comment             |
 |--------------------------------------|------------|------------|---------------------|
 | ctc-greedy-decoding                  | 2.03       | 4.37       | --epoch 50 --avg 26 |
+| ctc-prefix-beam-search               | 2.02       | 4.35       | --epoch 50 --avg 26 |
 
 The training command using 2 80G-A100 GPUs is:
 ```bash
@@ -292,7 +295,7 @@ export CUDA_VISIBLE_DEVICES="0,1"
 The decoding command is:
 ```bash
 export CUDA_VISIBLE_DEVICES="0"
-for m in ctc-greedy-search; do
+for m in ctc-greedy-search ctc-prefix-beam-search; do
   ./zipformer/ctc_decode.py \
     --epoch 50 \
     --avg 26 \
diff --git a/egs/librispeech/ASR/zipformer/ctc_decode.py b/egs/librispeech/ASR/zipformer/ctc_decode.py
index 9db4299592..fe9347b95a 100755
--- a/egs/librispeech/ASR/zipformer/ctc_decode.py
+++ b/egs/librispeech/ASR/zipformer/ctc_decode.py
@@ -111,6 +111,7 @@
 import argparse
 import logging
 import math
+import os
 from collections import defaultdict
 from pathlib import Path
 from typing import Dict, List, Optional, Tuple
@@ -129,8 +130,12 @@
     find_checkpoints,
     load_checkpoint,
 )
+from icefall.context_graph import ContextGraph, ContextState
 from icefall.decode import (
     ctc_greedy_search,
+    ctc_prefix_beam_search,
+    ctc_prefix_beam_search_attention_decoder_rescoring,
+    ctc_prefix_beam_search_shallow_fussion,
     get_lattice,
     nbest_decoding,
     nbest_oracle,
@@ -141,6 +146,8 @@
     rescore_with_whole_lattice,
 )
 from icefall.lexicon import Lexicon
+from icefall.lm_wrapper import LmScorer
+from icefall.ngram_lm import NgramLm, NgramLmStateCost
 from icefall.utils import (
     AttributeDict,
     get_texts,
@@ -255,6 +262,12 @@ def get_parser():
           lattice, rescore them with the attention decoder.
         - (9) attention-decoder-rescoring-with-ngram. Extract n paths from the LM
           rescored lattice, rescore them with the attention decoder.
+        - (10) ctc-prefix-beam-search. Extract n paths with the given beam, the best
+          path of the n paths is the decoding result.
+        - (11) ctc-prefix-beam-search-attention-decoder-rescoring. Extract n paths with
+          the given beam, rescore them with the attention decoder.
+        - (12) ctc-prefix-beam-search-shallow-fussion. Use NNLM shallow fussion during
+          beam search, LODR and hotwords are also supported in this decoding method.
         """,
     )
 
@@ -280,6 +293,23 @@ def get_parser():
         """,
     )
 
+    parser.add_argument(
+        "--nnlm-type",
+        type=str,
+        default="rnn",
+        help="Type of NN lm",
+        choices=["rnn", "transformer"],
+    )
+
+    parser.add_argument(
+        "--nnlm-scale",
+        type=float,
+        default=0,
+        help="""The scale of the neural network LM, 0 means don't use nnlm shallow fussion.
+        Used only when `--use-shallow-fusion` is set to True.
+        """,
+    )
+
     parser.add_argument(
         "--hlg-scale",
         type=float,
@@ -297,11 +327,52 @@ def get_parser():
         """,
     )
 
+    parser.add_argument(
+        "--backoff-id",
+        type=int,
+        default=500,
+        help="ID of the backoff symbol in the ngram LM",
+    )
+
+    parser.add_argument(
+        "--lodr-ngram",
+        type=str,
+        help="The path to the lodr ngram",
+    )
+
+    parser.add_argument(
+        "--lodr-lm-scale",
+        type=float,
+        default=0,
+        help="The scale of lodr ngram, should be less than 0. 0 means don't use lodr.",
+    )
+
+    parser.add_argument(
+        "--context-score",
+        type=float,
+        default=0,
+        help="""
+        The bonus score of each token for the context biasing words/phrases.
+        0 means don't use contextual biasing.
+        Used only when --decoding-method is ctc-prefix-beam-search-shallow-fussion.
+        """,
+    )
+
+    parser.add_argument(
+        "--context-file",
+        type=str,
+        default="",
+        help="""
+        The path of the context biasing lists, one word/phrase each line
+        Used only when --decoding-method is ctc-prefix-beam-search-shallow-fussion.
+        """,
+    )
+
     parser.add_argument(
         "--skip-scoring",
         type=str2bool,
         default=False,
-        help="""Skip scoring, but still save the ASR output (for eval sets)."""
+        help="""Skip scoring, but still save the ASR output (for eval sets).""",
     )
 
     add_model_arguments(parser)
@@ -314,11 +385,12 @@ def get_decoding_params() -> AttributeDict:
     params = AttributeDict(
         {
             "frame_shift_ms": 10,
-            "search_beam": 20,
-            "output_beam": 8,
+            "search_beam": 20,  # for k2 fsa composition
+            "output_beam": 8,  # for k2 fsa composition
             "min_active_states": 30,
             "max_active_states": 10000,
             "use_double_scores": True,
+            "beam": 4,  # for prefix-beam-search
         }
     )
     return params
@@ -333,6 +405,9 @@ def decode_one_batch(
     batch: dict,
     word_table: k2.SymbolTable,
     G: Optional[k2.Fsa] = None,
+    NNLM: Optional[LmScorer] = None,
+    LODR_lm: Optional[NgramLm] = None,
+    context_graph: Optional[ContextGraph] = None,
 ) -> Dict[str, List[List[str]]]:
     """Decode one batch and return the result in a dict. The dict has the
     following format:
@@ -377,10 +452,7 @@ def decode_one_batch(
       Return the decoding result. See above description for the format of
       the returned dict. Note: If it decodes to nothing, then return None.
     """
-    if HLG is not None:
-        device = HLG.device
-    else:
-        device = H.device
+    device = params.device
     feature = batch["inputs"]
     assert feature.ndim == 3
     feature = feature.to(device)
@@ -411,6 +483,51 @@ def decode_one_batch(
         key = "ctc-greedy-search"
         return {key: hyps}
 
+    if params.decoding_method == "ctc-prefix-beam-search":
+        token_ids = ctc_prefix_beam_search(
+            ctc_output=ctc_output, encoder_out_lens=encoder_out_lens
+        )
+        # hyps is a list of str, e.g., ['xxx yyy zzz', ...]
+        hyps = bpe_model.decode(token_ids)
+
+        # hyps is a list of list of str, e.g., [['xxx', 'yyy', 'zzz'], ... ]
+        hyps = [s.split() for s in hyps]
+        key = "prefix-beam-search"
+        return {key: hyps}
+
+    if params.decoding_method == "ctc-prefix-beam-search-attention-decoder-rescoring":
+        best_path_dict = ctc_prefix_beam_search_attention_decoder_rescoring(
+            ctc_output=ctc_output,
+            attention_decoder=model.attention_decoder,
+            encoder_out=encoder_out,
+            encoder_out_lens=encoder_out_lens,
+        )
+        ans = dict()
+        for a_scale_str, token_ids in best_path_dict.items():
+            # hyps is a list of str, e.g., ['xxx yyy zzz', ...]
+            hyps = bpe_model.decode(token_ids)
+            # hyps is a list of list of str, e.g., [['xxx', 'yyy', 'zzz'], ... ]
+            hyps = [s.split() for s in hyps]
+            ans[a_scale_str] = hyps
+        return ans
+
+    if params.decoding_method == "ctc-prefix-beam-search-shallow-fussion":
+        token_ids = ctc_prefix_beam_search_shallow_fussion(
+            ctc_output=ctc_output,
+            encoder_out_lens=encoder_out_lens,
+            NNLM=NNLM,
+            LODR_lm=LODR_lm,
+            LODR_lm_scale=params.lodr_lm_scale,
+            context_graph=context_graph,
+        )
+        # hyps is a list of str, e.g., ['xxx yyy zzz', ...]
+        hyps = bpe_model.decode(token_ids)
+
+        # hyps is a list of list of str, e.g., [['xxx', 'yyy', 'zzz'], ... ]
+        hyps = [s.split() for s in hyps]
+        key = "prefix-beam-search-shallow-fussion"
+        return {key: hyps}
+
     supervision_segments = torch.stack(
         (
             supervisions["sequence_idx"],
@@ -584,6 +701,9 @@ def decode_dataset(
     bpe_model: Optional[spm.SentencePieceProcessor],
     word_table: k2.SymbolTable,
     G: Optional[k2.Fsa] = None,
+    NNLM: Optional[LmScorer] = None,
+    LODR_lm: Optional[NgramLm] = None,
+    context_graph: Optional[ContextGraph] = None,
 ) -> Dict[str, List[Tuple[str, List[str], List[str]]]]:
     """Decode dataset.
 
@@ -634,6 +754,9 @@ def decode_dataset(
             batch=batch,
             word_table=word_table,
             G=G,
+            NNLM=NNLM,
+            LODR_lm=LODR_lm,
+            context_graph=context_graph,
         )
 
         for name, hyps in hyps_dict.items():
@@ -664,9 +787,7 @@ def save_asr_output(
     """
     for key, results in results_dict.items():
 
-        recogs_filename = (
-            params.res_dir / f"recogs-{test_set_name}-{params.suffix}.txt"
-        )
+        recogs_filename = params.res_dir / f"recogs-{test_set_name}-{params.suffix}.txt"
 
         results = sorted(results)
         store_transcripts(filename=recogs_filename, texts=results)
@@ -680,7 +801,8 @@ def save_wer_results(
     results_dict: Dict[str, List[Tuple[str, List[str], List[str]]]],
 ):
     if params.decoding_method in (
-        "attention-decoder-rescoring-with-ngram", "whole-lattice-rescoring"
+        "attention-decoder-rescoring-with-ngram",
+        "whole-lattice-rescoring",
     ):
         # Set it to False since there are too many logs.
         enable_log = False
@@ -721,6 +843,7 @@ def save_wer_results(
 def main():
     parser = get_parser()
     LibriSpeechAsrDataModule.add_arguments(parser)
+    LmScorer.add_arguments(parser)
     args = parser.parse_args()
     args.exp_dir = Path(args.exp_dir)
     args.lang_dir = Path(args.lang_dir)
@@ -735,8 +858,11 @@ def main():
     set_caching_enabled(True)  # lhotse
 
     assert params.decoding_method in (
-        "ctc-greedy-search",
         "ctc-decoding",
+        "ctc-greedy-search",
+        "ctc-prefix-beam-search",
+        "ctc-prefix-beam-search-attention-decoder-rescoring",
+        "ctc-prefix-beam-search-shallow-fussion",
         "1best",
         "nbest",
         "nbest-rescoring",
@@ -762,6 +888,16 @@ def main():
         params.suffix += f"_chunk-{params.chunk_size}"
         params.suffix += f"_left-context-{params.left_context_frames}"
 
+    if "prefix-beam-search" in params.decoding_method:
+        params.suffix += f"_beam-{params.beam}"
+        if params.decoding_method == "ctc-prefix-beam-search-shallow-fussion":
+            if params.nnlm_scale != 0:
+                params.suffix += f"_nnlm-scale-{params.nnlm_scale}"
+            if params.lodr_lm_scale != 0:
+                params.suffix += f"_lodr-scale-{params.lodr_lm_scale}"
+            if params.context_score != 0:
+                params.suffix += f"_context_score-{params.context_score}"
+
     if params.use_averaged_model:
         params.suffix += "_use-averaged-model"
 
@@ -771,6 +907,7 @@ def main():
     device = torch.device("cpu")
     if torch.cuda.is_available():
         device = torch.device("cuda", 0)
+    params.device = device
 
     logging.info(f"Device: {device}")
     logging.info(params)
@@ -786,14 +923,24 @@ def main():
     params.sos_id = 1
 
     if params.decoding_method in [
-        "ctc-greedy-search", "ctc-decoding", "attention-decoder-rescoring-no-ngram"
+        "ctc-decoding",
+        "ctc-greedy-search",
+        "ctc-prefix-beam-search",
+        "ctc-prefix-beam-search-attention-decoder-rescoring",
+        "ctc-prefix-beam-search-shallow-fussion",
+        "attention-decoder-rescoring-no-ngram",
     ]:
         HLG = None
-        H = k2.ctc_topo(
-            max_token=max_token_id,
-            modified=False,
-            device=device,
-        )
+        H = None
+        if params.decoding_method in [
+            "ctc-decoding",
+            "attention-decoder-rescoring-no-ngram",
+        ]:
+            H = k2.ctc_topo(
+                max_token=max_token_id,
+                modified=False,
+                device=device,
+            )
         bpe_model = spm.SentencePieceProcessor()
         bpe_model.load(str(params.lang_dir / "bpe.model"))
     else:
@@ -844,7 +991,8 @@ def main():
             G = k2.Fsa.from_dict(d)
 
         if params.decoding_method in [
-            "whole-lattice-rescoring", "attention-decoder-rescoring-with-ngram"
+            "whole-lattice-rescoring",
+            "attention-decoder-rescoring-with-ngram",
         ]:
             # Add epsilon self-loops to G as we will compose
             # it with the whole lattice later
@@ -858,6 +1006,51 @@ def main():
     else:
         G = None
 
+    # only load the neural network LM if required
+    NNLM = None
+    if (
+        params.decoding_method == "ctc-prefix-beam-search-shallow-fussion"
+        and params.nnlm_scale != 0
+    ):
+        NNLM = LmScorer(
+            lm_type=params.nnlm_type,
+            params=params,
+            device=device,
+            lm_scale=params.nnlm_scale,
+        )
+        NNLM.to(device)
+        NNLM.eval()
+
+    LODR_lm = None
+    if (
+        params.decoding_method == "ctc-prefix-beam-search-shallow-fussion"
+        and params.lodr_lm_scale != 0
+    ):
+        assert os.path.exists(
+            params.lodr_ngram
+        ), f"LODR ngram does not exists, given path : {params.lodr_ngram}"
+        logging.info(f"Loading LODR (token level lm): {params.lodr_ngram}")
+        LODR_lm = NgramLm(
+            params.lodr_ngram,
+            backoff_id=params.backoff_id,
+            is_binary=False,
+        )
+        logging.info(f"num states: {LODR_lm.lm.num_states}")
+
+    context_graph = None
+    if (
+        params.decoding_method == "ctc-prefix-beam-search-shallow-fussion"
+        and params.context_score != 0
+    ):
+        assert os.path.exists(
+            params.context_file
+        ), f"context_file does not exists, given path : {params.context_file}"
+        contexts = []
+        for line in open(params.context_file).readlines():
+            contexts.append(bpe_model.encode(line.strip()))
+        context_graph = ContextGraph(params.context_score)
+        context_graph.build(contexts)
+
     logging.info("About to create model")
     model = get_model(params)
 
@@ -967,6 +1160,9 @@ def main():
             bpe_model=bpe_model,
             word_table=lexicon.word_table,
             G=G,
+            NNLM=NNLM,
+            LODR_lm=LODR_lm,
+            context_graph=context_graph,
         )
 
         save_asr_output(
diff --git a/egs/ljspeech/TTS/.gitignore b/egs/ljspeech/TTS/.gitignore
new file mode 100644
index 0000000000..d5c19797ab
--- /dev/null
+++ b/egs/ljspeech/TTS/.gitignore
@@ -0,0 +1,7 @@
+build
+core.c
+*.so
+my-output*
+*.wav
+*.onnx
+generator_v*
diff --git a/egs/ljspeech/TTS/README.md b/egs/ljspeech/TTS/README.md
index 7b112c12c8..1cd6e8fd73 100644
--- a/egs/ljspeech/TTS/README.md
+++ b/egs/ljspeech/TTS/README.md
@@ -101,3 +101,121 @@ export CUDA_VISIBLE_DEVICES=4,5,6,7
 
 # (Note it is killed after `epoch-820.pt`)
 ```
+# matcha
+
+[./matcha](./matcha) contains the code for training [Matcha-TTS](https://github.com/shivammehta25/Matcha-TTS)
+
+This recipe provides a Matcha-TTS model trained on the LJSpeech dataset.
+
+Checkpoints and training logs can be found [here](https://huggingface.co/csukuangfj/icefall-tts-ljspeech-matcha-en-2024-10-28).
+The pull-request for this recipe can be found at <https://github.com/k2-fsa/icefall/pull/1773>
+
+The training command is given below:
+```bash
+export CUDA_VISIBLE_DEVICES=0,1,2,3
+
+python3 ./matcha/train.py \
+  --exp-dir ./matcha/exp-new-3/ \
+  --num-workers 4 \
+  --world-size 4 \
+  --num-epochs 4000 \
+  --max-duration 1000 \
+  --bucketing-sampler 1 \
+  --start-epoch 1
+```
+
+To inference, use:
+
+```bash
+# Download Hifigan vocoder. We use Hifigan v1 below. You can select from v1, v2, or v3
+
+wget https://github.com/csukuangfj/models/raw/refs/heads/master/hifigan/generator_v1
+
+./matcha/inference \
+  --exp-dir ./matcha/exp-new-3 \
+  --epoch 4000 \
+  --tokens ./data/tokens.txt \
+  --vocoder ./generator_v1 \
+  --input-text "how are you doing?"
+  --output-wav ./generated.wav
+```
+
+```bash
+soxi ./generated.wav
+```
+prints:
+```
+Input File     : './generated.wav'
+Channels       : 1
+Sample Rate    : 22050
+Precision      : 16-bit
+Duration       : 00:00:01.29 = 28416 samples ~ 96.6531 CDDA sectors
+File Size      : 56.9k
+Bit Rate       : 353k
+Sample Encoding: 16-bit Signed Integer PCM
+```
+
+To export the checkpoint to onnx:
+
+```bash
+# export the acoustic model to onnx
+
+./matcha/export_onnx.py \
+  --exp-dir ./matcha/exp-new-3 \
+  --epoch 4000 \
+  --tokens ./data/tokens.txt
+```
+
+The above command generate the following files:
+
+  - model-steps-2.onnx
+  - model-steps-3.onnx
+  - model-steps-4.onnx
+  - model-steps-5.onnx
+  - model-steps-6.onnx
+
+where the 2 in `model-steps-2.onnx` means it uses 2 steps for the ODE solver.
+
+
+To export the Hifigan vocoder to onnx, please use:
+
+```bash
+wget https://github.com/csukuangfj/models/raw/refs/heads/master/hifigan/generator_v1
+wget https://github.com/csukuangfj/models/raw/refs/heads/master/hifigan/generator_v2
+wget https://github.com/csukuangfj/models/raw/refs/heads/master/hifigan/generator_v3
+
+python3 ./matcha/export_onnx_hifigan.py
+```
+
+The above command generates 3 files:
+
+  - hifigan_v1.onnx
+  - hifigan_v2.onnx
+  - hifigan_v3.onnx
+
+To use the generated onnx files to generate speech from text, please run:
+
+```bash
+python3 ./matcha/onnx_pretrained.py \
+ --acoustic-model ./model-steps-6.onnx \
+ --vocoder ./hifigan_v1.onnx \
+ --tokens ./data/tokens.txt \
+ --input-text "Ask not what your country can do for you; ask what you can do for your country." \
+ --output-wav ./matcha-epoch-4000-step6-hfigian-v1.wav
+```
+
+```bash
+soxi ./matcha-epoch-4000-step6-hfigian-v1.wav
+
+Input File     : './matcha-epoch-4000-step6-hfigian-v1.wav'
+Channels       : 1
+Sample Rate    : 22050
+Precision      : 16-bit
+Duration       : 00:00:05.46 = 120320 samples ~ 409.252 CDDA sectors
+File Size      : 241k
+Bit Rate       : 353k
+Sample Encoding: 16-bit Signed Integer PCM
+```
+
+https://github.com/user-attachments/assets/b7c197a6-3870-49c6-90ca-db4d3776869b
+
diff --git a/egs/ljspeech/TTS/local/compute_fbank_ljspeech.py b/egs/ljspeech/TTS/local/compute_fbank_ljspeech.py
new file mode 100755
index 0000000000..5152ae675c
--- /dev/null
+++ b/egs/ljspeech/TTS/local/compute_fbank_ljspeech.py
@@ -0,0 +1,208 @@
+#!/usr/bin/env python3
+# Copyright    2021-2023  Xiaomi Corp.        (authors: Fangjun Kuang,
+#                                                       Zengwei Yao)
+#
+# See ../../../../LICENSE for clarification regarding multiple authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+"""
+This file computes fbank features of the LJSpeech dataset.
+It looks for manifests in the directory data/manifests.
+
+The generated fbank features are saved in data/fbank.
+"""
+
+import argparse
+import logging
+import os
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Union
+
+import numpy as np
+import torch
+from lhotse import CutSet, LilcomChunkyWriter, load_manifest
+from lhotse.audio import RecordingSet
+from lhotse.features.base import FeatureExtractor, register_extractor
+from lhotse.supervision import SupervisionSet
+from lhotse.utils import Seconds, compute_num_frames
+from matcha.audio import mel_spectrogram
+
+from icefall.utils import get_executor
+
+
+@dataclass
+class MyFbankConfig:
+    n_fft: int
+    n_mels: int
+    sampling_rate: int
+    hop_length: int
+    win_length: int
+    f_min: float
+    f_max: float
+
+
+@register_extractor
+class MyFbank(FeatureExtractor):
+
+    name = "MyFbank"
+    config_type = MyFbankConfig
+
+    def __init__(self, config):
+        super().__init__(config=config)
+
+    @property
+    def device(self) -> Union[str, torch.device]:
+        return self.config.device
+
+    def feature_dim(self, sampling_rate: int) -> int:
+        return self.config.n_mels
+
+    def extract(
+        self,
+        samples: np.ndarray,
+        sampling_rate: int,
+    ) -> torch.Tensor:
+        # Check for sampling rate compatibility.
+        expected_sr = self.config.sampling_rate
+        assert sampling_rate == expected_sr, (
+            f"Mismatched sampling rate: extractor expects {expected_sr}, "
+            f"got {sampling_rate}"
+        )
+        samples = torch.from_numpy(samples)
+        assert samples.ndim == 2, samples.shape
+        assert samples.shape[0] == 1, samples.shape
+
+        mel = (
+            mel_spectrogram(
+                samples,
+                self.config.n_fft,
+                self.config.n_mels,
+                self.config.sampling_rate,
+                self.config.hop_length,
+                self.config.win_length,
+                self.config.f_min,
+                self.config.f_max,
+                center=False,
+            )
+            .squeeze()
+            .t()
+        )
+
+        assert mel.ndim == 2, mel.shape
+        assert mel.shape[1] == self.config.n_mels, mel.shape
+
+        num_frames = compute_num_frames(
+            samples.shape[1] / sampling_rate, self.frame_shift, sampling_rate
+        )
+
+        if mel.shape[0] > num_frames:
+            mel = mel[:num_frames]
+        elif mel.shape[0] < num_frames:
+            mel = mel.unsqueeze(0)
+            mel = torch.nn.functional.pad(
+                mel, (0, 0, 0, num_frames - mel.shape[1]), mode="replicate"
+            ).squeeze(0)
+
+        return mel.numpy()
+
+    @property
+    def frame_shift(self) -> Seconds:
+        return self.config.hop_length / self.config.sampling_rate
+
+
+def get_parser():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter
+    )
+
+    parser.add_argument(
+        "--num-jobs",
+        type=int,
+        default=4,
+        help="""It specifies the checkpoint to use for decoding.
+        Note: Epoch counts from 1.
+        """,
+    )
+    return parser
+
+
+def compute_fbank_ljspeech(num_jobs: int):
+    src_dir = Path("data/manifests")
+    output_dir = Path("data/fbank")
+
+    if num_jobs < 1:
+        num_jobs = os.cpu_count()
+
+    logging.info(f"num_jobs: {num_jobs}")
+    logging.info(f"src_dir: {src_dir}")
+    logging.info(f"output_dir: {output_dir}")
+    config = MyFbankConfig(
+        n_fft=1024,
+        n_mels=80,
+        sampling_rate=22050,
+        hop_length=256,
+        win_length=1024,
+        f_min=0,
+        f_max=8000,
+    )
+
+    prefix = "ljspeech"
+    suffix = "jsonl.gz"
+    partition = "all"
+
+    recordings = load_manifest(
+        src_dir / f"{prefix}_recordings_{partition}.{suffix}", RecordingSet
+    )
+    supervisions = load_manifest(
+        src_dir / f"{prefix}_supervisions_{partition}.{suffix}", SupervisionSet
+    )
+
+    extractor = MyFbank(config)
+
+    with get_executor() as ex:  # Initialize the executor only once.
+        cuts_filename = f"{prefix}_cuts_{partition}.{suffix}"
+        if (output_dir / cuts_filename).is_file():
+            logging.info(f"{cuts_filename} already exists - skipping.")
+            return
+        logging.info(f"Processing {partition}")
+        cut_set = CutSet.from_manifests(
+            recordings=recordings, supervisions=supervisions
+        )
+
+        cut_set = cut_set.compute_and_store_features(
+            extractor=extractor,
+            storage_path=f"{output_dir}/{prefix}_feats_{partition}",
+            # when an executor is specified, make more partitions
+            num_jobs=num_jobs if ex is None else 80,
+            executor=ex,
+            storage_type=LilcomChunkyWriter,
+        )
+        cut_set.to_file(output_dir / cuts_filename)
+
+
+if __name__ == "__main__":
+    # Torch's multithreaded behavior needs to be disabled or
+    # it wastes a lot of CPU and slow things down.
+    # Do this outside of main() in case it needs to take effect
+    # even when we are not invoking the main (e.g. when spawning subprocesses).
+    torch.set_num_threads(1)
+    torch.set_num_interop_threads(1)
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+
+    args = get_parser().parse_args()
+    compute_fbank_ljspeech(args.num_jobs)
diff --git a/egs/ljspeech/TTS/local/compute_fbank_statistics.py b/egs/ljspeech/TTS/local/compute_fbank_statistics.py
new file mode 100755
index 0000000000..d0232c9832
--- /dev/null
+++ b/egs/ljspeech/TTS/local/compute_fbank_statistics.py
@@ -0,0 +1,84 @@
+#!/usr/bin/env python3
+# Copyright    2024  Xiaomi Corp.        (authors: Fangjun Kuang)
+#
+# See ../../../../LICENSE for clarification regarding multiple authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+This script compute the mean and std of the fbank features.
+"""
+
+import argparse
+import json
+import logging
+from pathlib import Path
+
+import torch
+from lhotse import CutSet, load_manifest_lazy
+
+
+def get_args():
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument(
+        "manifest",
+        type=Path,
+        help="Path to the manifest file",
+    )
+
+    parser.add_argument(
+        "cmvn",
+        type=Path,
+        help="Path to the cmvn.json",
+    )
+
+    return parser.parse_args()
+
+
+def main():
+    args = get_args()
+
+    manifest = args.manifest
+    logging.info(
+        f"Computing fbank mean and std for {manifest} and saving to {args.cmvn}"
+    )
+
+    assert manifest.is_file(), f"{manifest} does not exist"
+    cut_set = load_manifest_lazy(manifest)
+    assert isinstance(cut_set, CutSet), type(cut_set)
+
+    feat_dim = cut_set[0].features.num_features
+    num_frames = 0
+    s = 0
+    sq = 0
+    for c in cut_set:
+        f = torch.from_numpy(c.load_features())
+        num_frames += f.shape[0]
+        s += f.sum()
+        sq += f.square().sum()
+
+    fbank_mean = s / (num_frames * feat_dim)
+    fbank_var = sq / (num_frames * feat_dim) - fbank_mean * fbank_mean
+    print("fbank var", fbank_var)
+    fbank_std = fbank_var.sqrt()
+    with open(args.cmvn, "w") as f:
+        json.dump({"fbank_mean": fbank_mean.item(), "fbank_std": fbank_std.item()}, f)
+        f.write("\n")
+
+
+if __name__ == "__main__":
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+
+    main()
diff --git a/egs/ljspeech/TTS/local/prepare_tokens_ljspeech.py b/egs/ljspeech/TTS/local/prepare_tokens_ljspeech.py
index 4ba88604ce..33a8ac2ab7 100755
--- a/egs/ljspeech/TTS/local/prepare_tokens_ljspeech.py
+++ b/egs/ljspeech/TTS/local/prepare_tokens_ljspeech.py
@@ -28,17 +28,33 @@
 except ModuleNotFoundError as ex:
     raise RuntimeError(f"{ex}\nPlease run\n  pip install espnet_tts_frontend\n")
 
+import argparse
+
 from lhotse import CutSet, load_manifest
 from piper_phonemize import phonemize_espeak
 
 
-def prepare_tokens_ljspeech():
-    output_dir = Path("data/spectrogram")
+def get_parser():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter
+    )
+
+    parser.add_argument(
+        "--in-out-dir",
+        type=Path,
+        required=True,
+        help="Input and output directory",
+    )
+
+    return parser
+
+
+def prepare_tokens_ljspeech(in_out_dir):
     prefix = "ljspeech"
     suffix = "jsonl.gz"
     partition = "all"
 
-    cut_set = load_manifest(output_dir / f"{prefix}_cuts_{partition}.{suffix}")
+    cut_set = load_manifest(in_out_dir / f"{prefix}_cuts_{partition}.{suffix}")
 
     new_cuts = []
     for cut in cut_set:
@@ -56,11 +72,13 @@ def prepare_tokens_ljspeech():
         new_cuts.append(cut)
 
     new_cut_set = CutSet.from_cuts(new_cuts)
-    new_cut_set.to_file(output_dir / f"{prefix}_cuts_with_tokens_{partition}.{suffix}")
+    new_cut_set.to_file(in_out_dir / f"{prefix}_cuts_with_tokens_{partition}.{suffix}")
 
 
 if __name__ == "__main__":
     formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
     logging.basicConfig(format=formatter, level=logging.INFO)
 
-    prepare_tokens_ljspeech()
+    args = get_parser().parse_args()
+
+    prepare_tokens_ljspeech(args.in_out_dir)
diff --git a/egs/ljspeech/TTS/local/validate_manifest.py b/egs/ljspeech/TTS/local/validate_manifest.py
index 68159ae036..9535ba9f41 100755
--- a/egs/ljspeech/TTS/local/validate_manifest.py
+++ b/egs/ljspeech/TTS/local/validate_manifest.py
@@ -33,6 +33,7 @@
 import logging
 from pathlib import Path
 
+from compute_fbank_ljspeech import MyFbank
 from lhotse import CutSet, load_manifest_lazy
 from lhotse.dataset.speech_synthesis import validate_for_tts
 
diff --git a/egs/ljspeech/TTS/matcha/LICENSE b/egs/ljspeech/TTS/matcha/LICENSE
new file mode 100644
index 0000000000..858018e750
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 Shivam Mehta
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/egs/ljspeech/TTS/matcha/__init__.py b/egs/ljspeech/TTS/matcha/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/egs/ljspeech/TTS/matcha/audio.py b/egs/ljspeech/TTS/matcha/audio.py
new file mode 100644
index 0000000000..534331e596
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/audio.py
@@ -0,0 +1,92 @@
+# This file is copied from
+# https://github.com/shivammehta25/Matcha-TTS/blob/main/matcha/utils/audio.py
+import numpy as np
+import torch
+import torch.utils.data
+from librosa.filters import mel as librosa_mel_fn
+from scipy.io.wavfile import read
+
+MAX_WAV_VALUE = 32768.0
+
+
+def load_wav(full_path):
+    sampling_rate, data = read(full_path)
+    return data, sampling_rate
+
+
+def dynamic_range_compression(x, C=1, clip_val=1e-5):
+    return np.log(np.clip(x, a_min=clip_val, a_max=None) * C)
+
+
+def dynamic_range_decompression(x, C=1):
+    return np.exp(x) / C
+
+
+def dynamic_range_compression_torch(x, C=1, clip_val=1e-5):
+    return torch.log(torch.clamp(x, min=clip_val) * C)
+
+
+def dynamic_range_decompression_torch(x, C=1):
+    return torch.exp(x) / C
+
+
+def spectral_normalize_torch(magnitudes):
+    output = dynamic_range_compression_torch(magnitudes)
+    return output
+
+
+def spectral_de_normalize_torch(magnitudes):
+    output = dynamic_range_decompression_torch(magnitudes)
+    return output
+
+
+mel_basis = {}
+hann_window = {}
+
+
+def mel_spectrogram(
+    y, n_fft, num_mels, sampling_rate, hop_size, win_size, fmin, fmax, center=False
+):
+    if torch.min(y) < -1.0:
+        print("min value is ", torch.min(y))
+    if torch.max(y) > 1.0:
+        print("max value is ", torch.max(y))
+
+    global mel_basis, hann_window  # pylint: disable=global-statement
+    if f"{str(fmax)}_{str(y.device)}" not in mel_basis:
+        mel = librosa_mel_fn(
+            sr=sampling_rate, n_fft=n_fft, n_mels=num_mels, fmin=fmin, fmax=fmax
+        )
+        mel_basis[str(fmax) + "_" + str(y.device)] = (
+            torch.from_numpy(mel).float().to(y.device)
+        )
+        hann_window[str(y.device)] = torch.hann_window(win_size).to(y.device)
+
+    y = torch.nn.functional.pad(
+        y.unsqueeze(1),
+        (int((n_fft - hop_size) / 2), int((n_fft - hop_size) / 2)),
+        mode="reflect",
+    )
+    y = y.squeeze(1)
+
+    spec = torch.view_as_real(
+        torch.stft(
+            y,
+            n_fft,
+            hop_length=hop_size,
+            win_length=win_size,
+            window=hann_window[str(y.device)],
+            center=center,
+            pad_mode="reflect",
+            normalized=False,
+            onesided=True,
+            return_complex=True,
+        )
+    )
+
+    spec = torch.sqrt(spec.pow(2).sum(-1) + (1e-9))
+
+    spec = torch.matmul(mel_basis[str(fmax) + "_" + str(y.device)], spec)
+    spec = spectral_normalize_torch(spec)
+
+    return spec
diff --git a/egs/ljspeech/TTS/matcha/compute_fbank_ljspeech.py b/egs/ljspeech/TTS/matcha/compute_fbank_ljspeech.py
new file mode 120000
index 0000000000..85255ba0c0
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/compute_fbank_ljspeech.py
@@ -0,0 +1 @@
+../local/compute_fbank_ljspeech.py
\ No newline at end of file
diff --git a/egs/ljspeech/TTS/matcha/export_onnx.py b/egs/ljspeech/TTS/matcha/export_onnx.py
new file mode 100755
index 0000000000..487ea29952
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/export_onnx.py
@@ -0,0 +1,196 @@
+#!/usr/bin/env python3
+# Copyright         2024  Xiaomi Corp.        (authors: Fangjun Kuang)
+
+"""
+This script exports a Matcha-TTS model to ONNX.
+Note that the model outputs fbank. You need to use a vocoder to convert
+it to audio. See also ./export_onnx_hifigan.py
+"""
+
+import argparse
+import json
+import logging
+from pathlib import Path
+from typing import Any, Dict
+
+import onnx
+import torch
+from tokenizer import Tokenizer
+from train import get_model, get_params
+
+from icefall.checkpoint import load_checkpoint
+
+
+def get_parser():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter
+    )
+
+    parser.add_argument(
+        "--epoch",
+        type=int,
+        default=4000,
+        help="""It specifies the checkpoint to use for decoding.
+        Note: Epoch counts from 1.
+        """,
+    )
+
+    parser.add_argument(
+        "--exp-dir",
+        type=Path,
+        default="matcha/exp-new-3",
+        help="""The experiment dir.
+        It specifies the directory where all training related
+        files, e.g., checkpoints, log, etc, are saved
+        """,
+    )
+
+    parser.add_argument(
+        "--tokens",
+        type=Path,
+        default="data/tokens.txt",
+    )
+
+    parser.add_argument(
+        "--cmvn",
+        type=str,
+        default="data/fbank/cmvn.json",
+        help="""Path to vocabulary.""",
+    )
+
+    return parser
+
+
+def add_meta_data(filename: str, meta_data: Dict[str, Any]):
+    """Add meta data to an ONNX model. It is changed in-place.
+
+    Args:
+      filename:
+        Filename of the ONNX model to be changed.
+      meta_data:
+        Key-value pairs.
+    """
+    model = onnx.load(filename)
+
+    while len(model.metadata_props):
+        model.metadata_props.pop()
+
+    for key, value in meta_data.items():
+        meta = model.metadata_props.add()
+        meta.key = key
+        meta.value = str(value)
+
+    onnx.save(model, filename)
+
+
+class ModelWrapper(torch.nn.Module):
+    def __init__(self, model, num_steps: int = 5):
+        super().__init__()
+        self.model = model
+        self.num_steps = num_steps
+
+    def forward(
+        self,
+        x: torch.Tensor,
+        x_lengths: torch.Tensor,
+        temperature: torch.Tensor,
+        length_scale: torch.Tensor,
+    ) -> torch.Tensor:
+        """
+        Args: :
+          x: (batch_size, num_tokens), torch.int64
+          x_lengths: (batch_size,), torch.int64
+          temperature: (1,), torch.float32
+          length_scale (1,), torch.float32
+        Returns:
+          audio: (batch_size, num_samples)
+
+        """
+        mel = self.model.synthesise(
+            x=x,
+            x_lengths=x_lengths,
+            n_timesteps=self.num_steps,
+            temperature=temperature,
+            length_scale=length_scale,
+        )["mel"]
+        # mel: (batch_size, feat_dim, num_frames)
+
+        return mel
+
+
+@torch.inference_mode()
+def main():
+    parser = get_parser()
+    args = parser.parse_args()
+    params = get_params()
+
+    params.update(vars(args))
+
+    tokenizer = Tokenizer(params.tokens)
+    params.blank_id = tokenizer.pad_id
+    params.vocab_size = tokenizer.vocab_size
+    params.model_args.n_vocab = params.vocab_size
+
+    with open(params.cmvn) as f:
+        stats = json.load(f)
+        params.data_args.data_statistics.mel_mean = stats["fbank_mean"]
+        params.data_args.data_statistics.mel_std = stats["fbank_std"]
+
+        params.model_args.data_statistics.mel_mean = stats["fbank_mean"]
+        params.model_args.data_statistics.mel_std = stats["fbank_std"]
+    logging.info(params)
+
+    logging.info("About to create model")
+    model = get_model(params)
+    load_checkpoint(f"{params.exp_dir}/epoch-{params.epoch}.pt", model)
+
+    for num_steps in [2, 3, 4, 5, 6]:
+        logging.info(f"num_steps: {num_steps}")
+        wrapper = ModelWrapper(model, num_steps=num_steps)
+        wrapper.eval()
+
+        # Use a large value so the rotary position embedding in the text
+        # encoder has a large initial length
+        x = torch.ones(1, 1000, dtype=torch.int64)
+        x_lengths = torch.tensor([x.shape[1]], dtype=torch.int64)
+        temperature = torch.tensor([1.0])
+        length_scale = torch.tensor([1.0])
+
+        opset_version = 14
+        filename = f"model-steps-{num_steps}.onnx"
+        torch.onnx.export(
+            wrapper,
+            (x, x_lengths, temperature, length_scale),
+            filename,
+            opset_version=opset_version,
+            input_names=["x", "x_length", "temperature", "length_scale"],
+            output_names=["mel"],
+            dynamic_axes={
+                "x": {0: "N", 1: "L"},
+                "x_length": {0: "N"},
+                "mel": {0: "N", 2: "L"},
+            },
+        )
+
+        meta_data = {
+            "model_type": "matcha-tts",
+            "language": "English",
+            "voice": "en-us",
+            "has_espeak": 1,
+            "n_speakers": 1,
+            "sample_rate": 22050,
+            "version": 1,
+            "model_author": "icefall",
+            "maintainer": "k2-fsa",
+            "dataset": "LJ Speech",
+            "num_ode_steps": num_steps,
+        }
+        add_meta_data(filename=filename, meta_data=meta_data)
+        print(meta_data)
+
+
+if __name__ == "__main__":
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+    main()
diff --git a/egs/ljspeech/TTS/matcha/export_onnx_hifigan.py b/egs/ljspeech/TTS/matcha/export_onnx_hifigan.py
new file mode 100755
index 0000000000..63d1fac205
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/export_onnx_hifigan.py
@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+# Copyright         2024  Xiaomi Corp.        (authors: Fangjun Kuang)
+
+import logging
+from pathlib import Path
+from typing import Any, Dict
+
+import onnx
+import torch
+from inference import load_vocoder
+
+
+def add_meta_data(filename: str, meta_data: Dict[str, Any]):
+    """Add meta data to an ONNX model. It is changed in-place.
+
+    Args:
+      filename:
+        Filename of the ONNX model to be changed.
+      meta_data:
+        Key-value pairs.
+    """
+    model = onnx.load(filename)
+
+    while len(model.metadata_props):
+        model.metadata_props.pop()
+
+    for key, value in meta_data.items():
+        meta = model.metadata_props.add()
+        meta.key = key
+        meta.value = str(value)
+
+    onnx.save(model, filename)
+
+
+class ModelWrapper(torch.nn.Module):
+    def __init__(self, model):
+        super().__init__()
+        self.model = model
+
+    def forward(
+        self,
+        mel: torch.Tensor,
+    ) -> torch.Tensor:
+        """
+        Args: :
+          mel: (batch_size, feat_dim, num_frames), torch.float32
+        Returns:
+          audio: (batch_size, num_samples), torch.float32
+        """
+        audio = self.model(mel).clamp(-1, 1).squeeze(1)
+        return audio
+
+
+@torch.inference_mode()
+def main():
+    # Please go to
+    # https://github.com/csukuangfj/models/tree/master/hifigan
+    # to download the following files
+    model_filenames = ["./generator_v1", "./generator_v2", "./generator_v3"]
+
+    for f in model_filenames:
+        logging.info(f)
+        if not Path(f).is_file():
+            logging.info(f"Skipping {f} since {f} does not exist")
+            continue
+        model = load_vocoder(f)
+        wrapper = ModelWrapper(model)
+        wrapper.eval()
+        num_param = sum([p.numel() for p in wrapper.parameters()])
+        logging.info(f"{f}: Number of parameters: {num_param}")
+
+        # Use a large value so the rotary position embedding in the text
+        # encoder has a large initial length
+        x = torch.ones(1, 80, 100000, dtype=torch.float32)
+        opset_version = 14
+        suffix = f.split("_")[-1]
+        filename = f"hifigan_{suffix}.onnx"
+        torch.onnx.export(
+            wrapper,
+            x,
+            filename,
+            opset_version=opset_version,
+            input_names=["mel"],
+            output_names=["audio"],
+            dynamic_axes={
+                "mel": {0: "N", 2: "L"},
+                "audio": {0: "N", 1: "L"},
+            },
+        )
+
+        meta_data = {
+            "model_type": "hifigan",
+            "model_filename": f.split("/")[-1],
+            "sample_rate": 22050,
+            "version": 1,
+            "model_author": "jik876",
+            "maintainer": "k2-fsa",
+            "dataset": "LJ Speech",
+            "url1": "https://github.com/jik876/hifi-gan",
+            "url2": "https://github.com/csukuangfj/models/tree/master/hifigan",
+        }
+        add_meta_data(filename=filename, meta_data=meta_data)
+        print(meta_data)
+
+
+if __name__ == "__main__":
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+    main()
diff --git a/egs/ljspeech/TTS/matcha/hifigan/LICENSE b/egs/ljspeech/TTS/matcha/hifigan/LICENSE
new file mode 100644
index 0000000000..91751daed8
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/hifigan/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020 Jungil Kong
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/egs/ljspeech/TTS/matcha/hifigan/README.md b/egs/ljspeech/TTS/matcha/hifigan/README.md
new file mode 100644
index 0000000000..5db2585045
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/hifigan/README.md
@@ -0,0 +1,101 @@
+# HiFi-GAN: Generative Adversarial Networks for Efficient and High Fidelity Speech Synthesis
+
+### Jungil Kong, Jaehyeon Kim, Jaekyoung Bae
+
+In our [paper](https://arxiv.org/abs/2010.05646),
+we proposed HiFi-GAN: a GAN-based model capable of generating high fidelity speech efficiently.<br/>
+We provide our implementation and pretrained models as open source in this repository.
+
+**Abstract :**
+Several recent work on speech synthesis have employed generative adversarial networks (GANs) to produce raw waveforms.
+Although such methods improve the sampling efficiency and memory usage,
+their sample quality has not yet reached that of autoregressive and flow-based generative models.
+In this work, we propose HiFi-GAN, which achieves both efficient and high-fidelity speech synthesis.
+As speech audio consists of sinusoidal signals with various periods,
+we demonstrate that modeling periodic patterns of an audio is crucial for enhancing sample quality.
+A subjective human evaluation (mean opinion score, MOS) of a single speaker dataset indicates that our proposed method
+demonstrates similarity to human quality while generating 22.05 kHz high-fidelity audio 167.9 times faster than
+real-time on a single V100 GPU. We further show the generality of HiFi-GAN to the mel-spectrogram inversion of unseen
+speakers and end-to-end speech synthesis. Finally, a small footprint version of HiFi-GAN generates samples 13.4 times
+faster than real-time on CPU with comparable quality to an autoregressive counterpart.
+
+Visit our [demo website](https://jik876.github.io/hifi-gan-demo/) for audio samples.
+
+## Pre-requisites
+
+1. Python >= 3.6
+2. Clone this repository.
+3. Install python requirements. Please refer [requirements.txt](requirements.txt)
+4. Download and extract the [LJ Speech dataset](https://keithito.com/LJ-Speech-Dataset/).
+   And move all wav files to `LJSpeech-1.1/wavs`
+
+## Training
+
+```
+python train.py --config config_v1.json
+```
+
+To train V2 or V3 Generator, replace `config_v1.json` with `config_v2.json` or `config_v3.json`.<br>
+Checkpoints and copy of the configuration file are saved in `cp_hifigan` directory by default.<br>
+You can change the path by adding `--checkpoint_path` option.
+
+Validation loss during training with V1 generator.<br>
+![validation loss](./validation_loss.png)
+
+## Pretrained Model
+
+You can also use pretrained models we provide.<br/>
+[Download pretrained models](https://drive.google.com/drive/folders/1-eEYTB5Av9jNql0WGBlRoi-WH2J7bp5Y?usp=sharing)<br/>
+Details of each folder are as in follows:
+
+| Folder Name  | Generator | Dataset   | Fine-Tuned                                             |
+| ------------ | --------- | --------- | ------------------------------------------------------ |
+| LJ_V1        | V1        | LJSpeech  | No                                                     |
+| LJ_V2        | V2        | LJSpeech  | No                                                     |
+| LJ_V3        | V3        | LJSpeech  | No                                                     |
+| LJ_FT_T2_V1  | V1        | LJSpeech  | Yes ([Tacotron2](https://github.com/NVIDIA/tacotron2)) |
+| LJ_FT_T2_V2  | V2        | LJSpeech  | Yes ([Tacotron2](https://github.com/NVIDIA/tacotron2)) |
+| LJ_FT_T2_V3  | V3        | LJSpeech  | Yes ([Tacotron2](https://github.com/NVIDIA/tacotron2)) |
+| VCTK_V1      | V1        | VCTK      | No                                                     |
+| VCTK_V2      | V2        | VCTK      | No                                                     |
+| VCTK_V3      | V3        | VCTK      | No                                                     |
+| UNIVERSAL_V1 | V1        | Universal | No                                                     |
+
+We provide the universal model with discriminator weights that can be used as a base for transfer learning to other datasets.
+
+## Fine-Tuning
+
+1. Generate mel-spectrograms in numpy format using [Tacotron2](https://github.com/NVIDIA/tacotron2) with teacher-forcing.<br/>
+   The file name of the generated mel-spectrogram should match the audio file and the extension should be `.npy`.<br/>
+   Example:
+   `   Audio File : LJ001-0001.wav
+Mel-Spectrogram File : LJ001-0001.npy`
+2. Create `ft_dataset` folder and copy the generated mel-spectrogram files into it.<br/>
+3. Run the following command.
+   ```
+   python train.py --fine_tuning True --config config_v1.json
+   ```
+   For other command line options, please refer to the training section.
+
+## Inference from wav file
+
+1. Make `test_files` directory and copy wav files into the directory.
+2. Run the following command.
+   `   python inference.py --checkpoint_file [generator checkpoint file path]`
+   Generated wav files are saved in `generated_files` by default.<br>
+   You can change the path by adding `--output_dir` option.
+
+## Inference for end-to-end speech synthesis
+
+1. Make `test_mel_files` directory and copy generated mel-spectrogram files into the directory.<br>
+   You can generate mel-spectrograms using [Tacotron2](https://github.com/NVIDIA/tacotron2),
+   [Glow-TTS](https://github.com/jaywalnut310/glow-tts) and so forth.
+2. Run the following command.
+   `   python inference_e2e.py --checkpoint_file [generator checkpoint file path]`
+   Generated wav files are saved in `generated_files_from_mel` by default.<br>
+   You can change the path by adding `--output_dir` option.
+
+## Acknowledgements
+
+We referred to [WaveGlow](https://github.com/NVIDIA/waveglow), [MelGAN](https://github.com/descriptinc/melgan-neurips)
+and [Tacotron2](https://github.com/NVIDIA/tacotron2) to implement this.
diff --git a/egs/ljspeech/TTS/matcha/hifigan/__init__.py b/egs/ljspeech/TTS/matcha/hifigan/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/egs/ljspeech/TTS/matcha/hifigan/config.py b/egs/ljspeech/TTS/matcha/hifigan/config.py
new file mode 100644
index 0000000000..ecba62fd42
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/hifigan/config.py
@@ -0,0 +1,100 @@
+v1 = {
+    "resblock": "1",
+    "num_gpus": 0,
+    "batch_size": 16,
+    "learning_rate": 0.0004,
+    "adam_b1": 0.8,
+    "adam_b2": 0.99,
+    "lr_decay": 0.999,
+    "seed": 1234,
+    "upsample_rates": [8, 8, 2, 2],
+    "upsample_kernel_sizes": [16, 16, 4, 4],
+    "upsample_initial_channel": 512,
+    "resblock_kernel_sizes": [3, 7, 11],
+    "resblock_dilation_sizes": [[1, 3, 5], [1, 3, 5], [1, 3, 5]],
+    "resblock_initial_channel": 256,
+    "segment_size": 8192,
+    "num_mels": 80,
+    "num_freq": 1025,
+    "n_fft": 1024,
+    "hop_size": 256,
+    "win_size": 1024,
+    "sampling_rate": 22050,
+    "fmin": 0,
+    "fmax": 8000,
+    "fmax_loss": None,
+    "num_workers": 4,
+    "dist_config": {
+        "dist_backend": "nccl",
+        "dist_url": "tcp://localhost:54321",
+        "world_size": 1,
+    },
+}
+
+# See https://drive.google.com/drive/folders/1bB1tnGIxRN-edlf6k2Rmi1gNCK9Cpcvf
+v2 = {
+    "resblock": "1",
+    "num_gpus": 0,
+    "batch_size": 16,
+    "learning_rate": 0.0002,
+    "adam_b1": 0.8,
+    "adam_b2": 0.99,
+    "lr_decay": 0.999,
+    "seed": 1234,
+    "upsample_rates": [8, 8, 2, 2],
+    "upsample_kernel_sizes": [16, 16, 4, 4],
+    "upsample_initial_channel": 128,
+    "resblock_kernel_sizes": [3, 7, 11],
+    "resblock_dilation_sizes": [[1, 3, 5], [1, 3, 5], [1, 3, 5]],
+    "resblock_initial_channel": 64,
+    "segment_size": 8192,
+    "num_mels": 80,
+    "num_freq": 1025,
+    "n_fft": 1024,
+    "hop_size": 256,
+    "win_size": 1024,
+    "sampling_rate": 22050,
+    "fmin": 0,
+    "fmax": 8000,
+    "fmax_loss": None,
+    "num_workers": 4,
+    "dist_config": {
+        "dist_backend": "nccl",
+        "dist_url": "tcp://localhost:54321",
+        "world_size": 1,
+    },
+}
+
+# See https://drive.google.com/drive/folders/1KKvuJTLp_gZXC8lug7H_lSXct38_3kx1
+v3 = {
+    "resblock": "2",
+    "num_gpus": 0,
+    "batch_size": 16,
+    "learning_rate": 0.0002,
+    "adam_b1": 0.8,
+    "adam_b2": 0.99,
+    "lr_decay": 0.999,
+    "seed": 1234,
+    "upsample_rates": [8, 8, 4],
+    "upsample_kernel_sizes": [16, 16, 8],
+    "upsample_initial_channel": 256,
+    "resblock_kernel_sizes": [3, 5, 7],
+    "resblock_dilation_sizes": [[1, 2], [2, 6], [3, 12]],
+    "resblock_initial_channel": 128,
+    "segment_size": 8192,
+    "num_mels": 80,
+    "num_freq": 1025,
+    "n_fft": 1024,
+    "hop_size": 256,
+    "win_size": 1024,
+    "sampling_rate": 22050,
+    "fmin": 0,
+    "fmax": 8000,
+    "fmax_loss": None,
+    "num_workers": 4,
+    "dist_config": {
+        "dist_backend": "nccl",
+        "dist_url": "tcp://localhost:54321",
+        "world_size": 1,
+    },
+}
diff --git a/egs/ljspeech/TTS/matcha/hifigan/denoiser.py b/egs/ljspeech/TTS/matcha/hifigan/denoiser.py
new file mode 100644
index 0000000000..b9aea61b8e
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/hifigan/denoiser.py
@@ -0,0 +1,71 @@
+# Code modified from Rafael Valle's implementation https://github.com/NVIDIA/waveglow/blob/5bc2a53e20b3b533362f974cfa1ea0267ae1c2b1/denoiser.py
+
+"""Waveglow style denoiser can be used to remove the artifacts from the HiFiGAN generated audio."""
+import torch
+
+
+class Denoiser(torch.nn.Module):
+    """Removes model bias from audio produced with waveglow"""
+
+    def __init__(
+        self, vocoder, filter_length=1024, n_overlap=4, win_length=1024, mode="zeros"
+    ):
+        super().__init__()
+        self.filter_length = filter_length
+        self.hop_length = int(filter_length / n_overlap)
+        self.win_length = win_length
+
+        dtype, device = (
+            next(vocoder.parameters()).dtype,
+            next(vocoder.parameters()).device,
+        )
+        self.device = device
+        if mode == "zeros":
+            mel_input = torch.zeros((1, 80, 88), dtype=dtype, device=device)
+        elif mode == "normal":
+            mel_input = torch.randn((1, 80, 88), dtype=dtype, device=device)
+        else:
+            raise Exception(f"Mode {mode} if not supported")
+
+        def stft_fn(audio, n_fft, hop_length, win_length, window):
+            spec = torch.stft(
+                audio,
+                n_fft=n_fft,
+                hop_length=hop_length,
+                win_length=win_length,
+                window=window,
+                return_complex=True,
+            )
+            spec = torch.view_as_real(spec)
+            return torch.sqrt(spec.pow(2).sum(-1)), torch.atan2(
+                spec[..., -1], spec[..., 0]
+            )
+
+        self.stft = lambda x: stft_fn(
+            audio=x,
+            n_fft=self.filter_length,
+            hop_length=self.hop_length,
+            win_length=self.win_length,
+            window=torch.hann_window(self.win_length, device=device),
+        )
+        self.istft = lambda x, y: torch.istft(
+            torch.complex(x * torch.cos(y), x * torch.sin(y)),
+            n_fft=self.filter_length,
+            hop_length=self.hop_length,
+            win_length=self.win_length,
+            window=torch.hann_window(self.win_length, device=device),
+        )
+
+        with torch.no_grad():
+            bias_audio = vocoder(mel_input).float().squeeze(0)
+            bias_spec, _ = self.stft(bias_audio)
+
+        self.register_buffer("bias_spec", bias_spec[:, :, 0][:, :, None])
+
+    @torch.inference_mode()
+    def forward(self, audio, strength=0.0005):
+        audio_spec, audio_angles = self.stft(audio)
+        audio_spec_denoised = audio_spec - self.bias_spec.to(audio.device) * strength
+        audio_spec_denoised = torch.clamp(audio_spec_denoised, 0.0)
+        audio_denoised = self.istft(audio_spec_denoised, audio_angles)
+        return audio_denoised
diff --git a/egs/ljspeech/TTS/matcha/hifigan/env.py b/egs/ljspeech/TTS/matcha/hifigan/env.py
new file mode 100644
index 0000000000..9ea4f948a3
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/hifigan/env.py
@@ -0,0 +1,17 @@
+""" from https://github.com/jik876/hifi-gan """
+
+import os
+import shutil
+
+
+class AttrDict(dict):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.__dict__ = self
+
+
+def build_env(config, config_name, path):
+    t_path = os.path.join(path, config_name)
+    if config != t_path:
+        os.makedirs(path, exist_ok=True)
+        shutil.copyfile(config, os.path.join(path, config_name))
diff --git a/egs/ljspeech/TTS/matcha/hifigan/meldataset.py b/egs/ljspeech/TTS/matcha/hifigan/meldataset.py
new file mode 100644
index 0000000000..6eb15a326c
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/hifigan/meldataset.py
@@ -0,0 +1,245 @@
+""" from https://github.com/jik876/hifi-gan """
+
+import math
+import os
+import random
+
+import numpy as np
+import torch
+import torch.utils.data
+from librosa.filters import mel as librosa_mel_fn
+from librosa.util import normalize
+from scipy.io.wavfile import read
+
+MAX_WAV_VALUE = 32768.0
+
+
+def load_wav(full_path):
+    sampling_rate, data = read(full_path)
+    return data, sampling_rate
+
+
+def dynamic_range_compression(x, C=1, clip_val=1e-5):
+    return np.log(np.clip(x, a_min=clip_val, a_max=None) * C)
+
+
+def dynamic_range_decompression(x, C=1):
+    return np.exp(x) / C
+
+
+def dynamic_range_compression_torch(x, C=1, clip_val=1e-5):
+    return torch.log(torch.clamp(x, min=clip_val) * C)
+
+
+def dynamic_range_decompression_torch(x, C=1):
+    return torch.exp(x) / C
+
+
+def spectral_normalize_torch(magnitudes):
+    output = dynamic_range_compression_torch(magnitudes)
+    return output
+
+
+def spectral_de_normalize_torch(magnitudes):
+    output = dynamic_range_decompression_torch(magnitudes)
+    return output
+
+
+mel_basis = {}
+hann_window = {}
+
+
+def mel_spectrogram(
+    y, n_fft, num_mels, sampling_rate, hop_size, win_size, fmin, fmax, center=False
+):
+    if torch.min(y) < -1.0:
+        print("min value is ", torch.min(y))
+    if torch.max(y) > 1.0:
+        print("max value is ", torch.max(y))
+
+    global mel_basis, hann_window  # pylint: disable=global-statement
+    if fmax not in mel_basis:
+        mel = librosa_mel_fn(sampling_rate, n_fft, num_mels, fmin, fmax)
+        mel_basis[str(fmax) + "_" + str(y.device)] = (
+            torch.from_numpy(mel).float().to(y.device)
+        )
+        hann_window[str(y.device)] = torch.hann_window(win_size).to(y.device)
+
+    y = torch.nn.functional.pad(
+        y.unsqueeze(1),
+        (int((n_fft - hop_size) / 2), int((n_fft - hop_size) / 2)),
+        mode="reflect",
+    )
+    y = y.squeeze(1)
+
+    spec = torch.view_as_real(
+        torch.stft(
+            y,
+            n_fft,
+            hop_length=hop_size,
+            win_length=win_size,
+            window=hann_window[str(y.device)],
+            center=center,
+            pad_mode="reflect",
+            normalized=False,
+            onesided=True,
+            return_complex=True,
+        )
+    )
+
+    spec = torch.sqrt(spec.pow(2).sum(-1) + (1e-9))
+
+    spec = torch.matmul(mel_basis[str(fmax) + "_" + str(y.device)], spec)
+    spec = spectral_normalize_torch(spec)
+
+    return spec
+
+
+def get_dataset_filelist(a):
+    with open(a.input_training_file, encoding="utf-8") as fi:
+        training_files = [
+            os.path.join(a.input_wavs_dir, x.split("|")[0] + ".wav")
+            for x in fi.read().split("\n")
+            if len(x) > 0
+        ]
+
+    with open(a.input_validation_file, encoding="utf-8") as fi:
+        validation_files = [
+            os.path.join(a.input_wavs_dir, x.split("|")[0] + ".wav")
+            for x in fi.read().split("\n")
+            if len(x) > 0
+        ]
+    return training_files, validation_files
+
+
+class MelDataset(torch.utils.data.Dataset):
+    def __init__(
+        self,
+        training_files,
+        segment_size,
+        n_fft,
+        num_mels,
+        hop_size,
+        win_size,
+        sampling_rate,
+        fmin,
+        fmax,
+        split=True,
+        shuffle=True,
+        n_cache_reuse=1,
+        device=None,
+        fmax_loss=None,
+        fine_tuning=False,
+        base_mels_path=None,
+    ):
+        self.audio_files = training_files
+        random.seed(1234)
+        if shuffle:
+            random.shuffle(self.audio_files)
+        self.segment_size = segment_size
+        self.sampling_rate = sampling_rate
+        self.split = split
+        self.n_fft = n_fft
+        self.num_mels = num_mels
+        self.hop_size = hop_size
+        self.win_size = win_size
+        self.fmin = fmin
+        self.fmax = fmax
+        self.fmax_loss = fmax_loss
+        self.cached_wav = None
+        self.n_cache_reuse = n_cache_reuse
+        self._cache_ref_count = 0
+        self.device = device
+        self.fine_tuning = fine_tuning
+        self.base_mels_path = base_mels_path
+
+    def __getitem__(self, index):
+        filename = self.audio_files[index]
+        if self._cache_ref_count == 0:
+            audio, sampling_rate = load_wav(filename)
+            audio = audio / MAX_WAV_VALUE
+            if not self.fine_tuning:
+                audio = normalize(audio) * 0.95
+            self.cached_wav = audio
+            if sampling_rate != self.sampling_rate:
+                raise ValueError(
+                    f"{sampling_rate} SR doesn't match target {self.sampling_rate} SR"
+                )
+            self._cache_ref_count = self.n_cache_reuse
+        else:
+            audio = self.cached_wav
+            self._cache_ref_count -= 1
+
+        audio = torch.FloatTensor(audio)
+        audio = audio.unsqueeze(0)
+
+        if not self.fine_tuning:
+            if self.split:
+                if audio.size(1) >= self.segment_size:
+                    max_audio_start = audio.size(1) - self.segment_size
+                    audio_start = random.randint(0, max_audio_start)
+                    audio = audio[:, audio_start : audio_start + self.segment_size]
+                else:
+                    audio = torch.nn.functional.pad(
+                        audio, (0, self.segment_size - audio.size(1)), "constant"
+                    )
+
+            mel = mel_spectrogram(
+                audio,
+                self.n_fft,
+                self.num_mels,
+                self.sampling_rate,
+                self.hop_size,
+                self.win_size,
+                self.fmin,
+                self.fmax,
+                center=False,
+            )
+        else:
+            mel = np.load(
+                os.path.join(
+                    self.base_mels_path,
+                    os.path.splitext(os.path.split(filename)[-1])[0] + ".npy",
+                )
+            )
+            mel = torch.from_numpy(mel)
+
+            if len(mel.shape) < 3:
+                mel = mel.unsqueeze(0)
+
+            if self.split:
+                frames_per_seg = math.ceil(self.segment_size / self.hop_size)
+
+                if audio.size(1) >= self.segment_size:
+                    mel_start = random.randint(0, mel.size(2) - frames_per_seg - 1)
+                    mel = mel[:, :, mel_start : mel_start + frames_per_seg]
+                    audio = audio[
+                        :,
+                        mel_start
+                        * self.hop_size : (mel_start + frames_per_seg)
+                        * self.hop_size,
+                    ]
+                else:
+                    mel = torch.nn.functional.pad(
+                        mel, (0, frames_per_seg - mel.size(2)), "constant"
+                    )
+                    audio = torch.nn.functional.pad(
+                        audio, (0, self.segment_size - audio.size(1)), "constant"
+                    )
+
+        mel_loss = mel_spectrogram(
+            audio,
+            self.n_fft,
+            self.num_mels,
+            self.sampling_rate,
+            self.hop_size,
+            self.win_size,
+            self.fmin,
+            self.fmax_loss,
+            center=False,
+        )
+
+        return (mel.squeeze(), audio.squeeze(0), filename, mel_loss.squeeze())
+
+    def __len__(self):
+        return len(self.audio_files)
diff --git a/egs/ljspeech/TTS/matcha/hifigan/models.py b/egs/ljspeech/TTS/matcha/hifigan/models.py
new file mode 100644
index 0000000000..e6da206108
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/hifigan/models.py
@@ -0,0 +1,406 @@
+""" from https://github.com/jik876/hifi-gan """
+
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+from torch.nn import AvgPool1d, Conv1d, Conv2d, ConvTranspose1d
+from torch.nn.utils import remove_weight_norm, spectral_norm, weight_norm
+
+from .xutils import get_padding, init_weights
+
+LRELU_SLOPE = 0.1
+
+
+class ResBlock1(torch.nn.Module):
+    def __init__(self, h, channels, kernel_size=3, dilation=(1, 3, 5)):
+        super().__init__()
+        self.h = h
+        self.convs1 = nn.ModuleList(
+            [
+                weight_norm(
+                    Conv1d(
+                        channels,
+                        channels,
+                        kernel_size,
+                        1,
+                        dilation=dilation[0],
+                        padding=get_padding(kernel_size, dilation[0]),
+                    )
+                ),
+                weight_norm(
+                    Conv1d(
+                        channels,
+                        channels,
+                        kernel_size,
+                        1,
+                        dilation=dilation[1],
+                        padding=get_padding(kernel_size, dilation[1]),
+                    )
+                ),
+                weight_norm(
+                    Conv1d(
+                        channels,
+                        channels,
+                        kernel_size,
+                        1,
+                        dilation=dilation[2],
+                        padding=get_padding(kernel_size, dilation[2]),
+                    )
+                ),
+            ]
+        )
+        self.convs1.apply(init_weights)
+
+        self.convs2 = nn.ModuleList(
+            [
+                weight_norm(
+                    Conv1d(
+                        channels,
+                        channels,
+                        kernel_size,
+                        1,
+                        dilation=1,
+                        padding=get_padding(kernel_size, 1),
+                    )
+                ),
+                weight_norm(
+                    Conv1d(
+                        channels,
+                        channels,
+                        kernel_size,
+                        1,
+                        dilation=1,
+                        padding=get_padding(kernel_size, 1),
+                    )
+                ),
+                weight_norm(
+                    Conv1d(
+                        channels,
+                        channels,
+                        kernel_size,
+                        1,
+                        dilation=1,
+                        padding=get_padding(kernel_size, 1),
+                    )
+                ),
+            ]
+        )
+        self.convs2.apply(init_weights)
+
+    def forward(self, x):
+        for c1, c2 in zip(self.convs1, self.convs2):
+            xt = F.leaky_relu(x, LRELU_SLOPE)
+            xt = c1(xt)
+            xt = F.leaky_relu(xt, LRELU_SLOPE)
+            xt = c2(xt)
+            x = xt + x
+        return x
+
+    def remove_weight_norm(self):
+        for l in self.convs1:
+            remove_weight_norm(l)
+        for l in self.convs2:
+            remove_weight_norm(l)
+
+
+class ResBlock2(torch.nn.Module):
+    def __init__(self, h, channels, kernel_size=3, dilation=(1, 3)):
+        super().__init__()
+        self.h = h
+        self.convs = nn.ModuleList(
+            [
+                weight_norm(
+                    Conv1d(
+                        channels,
+                        channels,
+                        kernel_size,
+                        1,
+                        dilation=dilation[0],
+                        padding=get_padding(kernel_size, dilation[0]),
+                    )
+                ),
+                weight_norm(
+                    Conv1d(
+                        channels,
+                        channels,
+                        kernel_size,
+                        1,
+                        dilation=dilation[1],
+                        padding=get_padding(kernel_size, dilation[1]),
+                    )
+                ),
+            ]
+        )
+        self.convs.apply(init_weights)
+
+    def forward(self, x):
+        for c in self.convs:
+            xt = F.leaky_relu(x, LRELU_SLOPE)
+            xt = c(xt)
+            x = xt + x
+        return x
+
+    def remove_weight_norm(self):
+        for l in self.convs:
+            remove_weight_norm(l)
+
+
+class Generator(torch.nn.Module):
+    def __init__(self, h):
+        super().__init__()
+        self.h = h
+        self.num_kernels = len(h.resblock_kernel_sizes)
+        self.num_upsamples = len(h.upsample_rates)
+        self.conv_pre = weight_norm(
+            Conv1d(80, h.upsample_initial_channel, 7, 1, padding=3)
+        )
+        resblock = ResBlock1 if h.resblock == "1" else ResBlock2
+
+        self.ups = nn.ModuleList()
+        for i, (u, k) in enumerate(zip(h.upsample_rates, h.upsample_kernel_sizes)):
+            self.ups.append(
+                weight_norm(
+                    ConvTranspose1d(
+                        h.upsample_initial_channel // (2**i),
+                        h.upsample_initial_channel // (2 ** (i + 1)),
+                        k,
+                        u,
+                        padding=(k - u) // 2,
+                    )
+                )
+            )
+
+        self.resblocks = nn.ModuleList()
+        for i in range(len(self.ups)):
+            ch = h.upsample_initial_channel // (2 ** (i + 1))
+            for _, (k, d) in enumerate(
+                zip(h.resblock_kernel_sizes, h.resblock_dilation_sizes)
+            ):
+                self.resblocks.append(resblock(h, ch, k, d))
+
+        self.conv_post = weight_norm(Conv1d(ch, 1, 7, 1, padding=3))
+        self.ups.apply(init_weights)
+        self.conv_post.apply(init_weights)
+
+    def forward(self, x):
+        x = self.conv_pre(x)
+        for i in range(self.num_upsamples):
+            x = F.leaky_relu(x, LRELU_SLOPE)
+            x = self.ups[i](x)
+            xs = None
+            for j in range(self.num_kernels):
+                if xs is None:
+                    xs = self.resblocks[i * self.num_kernels + j](x)
+                else:
+                    xs += self.resblocks[i * self.num_kernels + j](x)
+            x = xs / self.num_kernels
+        x = F.leaky_relu(x)
+        x = self.conv_post(x)
+        x = torch.tanh(x)
+
+        return x
+
+    def remove_weight_norm(self):
+        print("Removing weight norm...")
+        for l in self.ups:
+            remove_weight_norm(l)
+        for l in self.resblocks:
+            l.remove_weight_norm()
+        remove_weight_norm(self.conv_pre)
+        remove_weight_norm(self.conv_post)
+
+
+class DiscriminatorP(torch.nn.Module):
+    def __init__(self, period, kernel_size=5, stride=3, use_spectral_norm=False):
+        super().__init__()
+        self.period = period
+        norm_f = weight_norm if use_spectral_norm is False else spectral_norm
+        self.convs = nn.ModuleList(
+            [
+                norm_f(
+                    Conv2d(
+                        1,
+                        32,
+                        (kernel_size, 1),
+                        (stride, 1),
+                        padding=(get_padding(5, 1), 0),
+                    )
+                ),
+                norm_f(
+                    Conv2d(
+                        32,
+                        128,
+                        (kernel_size, 1),
+                        (stride, 1),
+                        padding=(get_padding(5, 1), 0),
+                    )
+                ),
+                norm_f(
+                    Conv2d(
+                        128,
+                        512,
+                        (kernel_size, 1),
+                        (stride, 1),
+                        padding=(get_padding(5, 1), 0),
+                    )
+                ),
+                norm_f(
+                    Conv2d(
+                        512,
+                        1024,
+                        (kernel_size, 1),
+                        (stride, 1),
+                        padding=(get_padding(5, 1), 0),
+                    )
+                ),
+                norm_f(Conv2d(1024, 1024, (kernel_size, 1), 1, padding=(2, 0))),
+            ]
+        )
+        self.conv_post = norm_f(Conv2d(1024, 1, (3, 1), 1, padding=(1, 0)))
+
+    def forward(self, x):
+        fmap = []
+
+        # 1d to 2d
+        b, c, t = x.shape
+        if t % self.period != 0:  # pad first
+            n_pad = self.period - (t % self.period)
+            x = F.pad(x, (0, n_pad), "reflect")
+            t = t + n_pad
+        x = x.view(b, c, t // self.period, self.period)
+
+        for l in self.convs:
+            x = l(x)
+            x = F.leaky_relu(x, LRELU_SLOPE)
+            fmap.append(x)
+        x = self.conv_post(x)
+        fmap.append(x)
+        x = torch.flatten(x, 1, -1)
+
+        return x, fmap
+
+
+class MultiPeriodDiscriminator(torch.nn.Module):
+    def __init__(self):
+        super().__init__()
+        self.discriminators = nn.ModuleList(
+            [
+                DiscriminatorP(2),
+                DiscriminatorP(3),
+                DiscriminatorP(5),
+                DiscriminatorP(7),
+                DiscriminatorP(11),
+            ]
+        )
+
+    def forward(self, y, y_hat):
+        y_d_rs = []
+        y_d_gs = []
+        fmap_rs = []
+        fmap_gs = []
+        for _, d in enumerate(self.discriminators):
+            y_d_r, fmap_r = d(y)
+            y_d_g, fmap_g = d(y_hat)
+            y_d_rs.append(y_d_r)
+            fmap_rs.append(fmap_r)
+            y_d_gs.append(y_d_g)
+            fmap_gs.append(fmap_g)
+
+        return y_d_rs, y_d_gs, fmap_rs, fmap_gs
+
+
+class DiscriminatorS(torch.nn.Module):
+    def __init__(self, use_spectral_norm=False):
+        super().__init__()
+        norm_f = weight_norm if use_spectral_norm is False else spectral_norm
+        self.convs = nn.ModuleList(
+            [
+                norm_f(Conv1d(1, 128, 15, 1, padding=7)),
+                norm_f(Conv1d(128, 128, 41, 2, groups=4, padding=20)),
+                norm_f(Conv1d(128, 256, 41, 2, groups=16, padding=20)),
+                norm_f(Conv1d(256, 512, 41, 4, groups=16, padding=20)),
+                norm_f(Conv1d(512, 1024, 41, 4, groups=16, padding=20)),
+                norm_f(Conv1d(1024, 1024, 41, 1, groups=16, padding=20)),
+                norm_f(Conv1d(1024, 1024, 5, 1, padding=2)),
+            ]
+        )
+        self.conv_post = norm_f(Conv1d(1024, 1, 3, 1, padding=1))
+
+    def forward(self, x):
+        fmap = []
+        for l in self.convs:
+            x = l(x)
+            x = F.leaky_relu(x, LRELU_SLOPE)
+            fmap.append(x)
+        x = self.conv_post(x)
+        fmap.append(x)
+        x = torch.flatten(x, 1, -1)
+
+        return x, fmap
+
+
+class MultiScaleDiscriminator(torch.nn.Module):
+    def __init__(self):
+        super().__init__()
+        self.discriminators = nn.ModuleList(
+            [
+                DiscriminatorS(use_spectral_norm=True),
+                DiscriminatorS(),
+                DiscriminatorS(),
+            ]
+        )
+        self.meanpools = nn.ModuleList(
+            [AvgPool1d(4, 2, padding=2), AvgPool1d(4, 2, padding=2)]
+        )
+
+    def forward(self, y, y_hat):
+        y_d_rs = []
+        y_d_gs = []
+        fmap_rs = []
+        fmap_gs = []
+        for i, d in enumerate(self.discriminators):
+            if i != 0:
+                y = self.meanpools[i - 1](y)
+                y_hat = self.meanpools[i - 1](y_hat)
+            y_d_r, fmap_r = d(y)
+            y_d_g, fmap_g = d(y_hat)
+            y_d_rs.append(y_d_r)
+            fmap_rs.append(fmap_r)
+            y_d_gs.append(y_d_g)
+            fmap_gs.append(fmap_g)
+
+        return y_d_rs, y_d_gs, fmap_rs, fmap_gs
+
+
+def feature_loss(fmap_r, fmap_g):
+    loss = 0
+    for dr, dg in zip(fmap_r, fmap_g):
+        for rl, gl in zip(dr, dg):
+            loss += torch.mean(torch.abs(rl - gl))
+
+    return loss * 2
+
+
+def discriminator_loss(disc_real_outputs, disc_generated_outputs):
+    loss = 0
+    r_losses = []
+    g_losses = []
+    for dr, dg in zip(disc_real_outputs, disc_generated_outputs):
+        r_loss = torch.mean((1 - dr) ** 2)
+        g_loss = torch.mean(dg**2)
+        loss += r_loss + g_loss
+        r_losses.append(r_loss.item())
+        g_losses.append(g_loss.item())
+
+    return loss, r_losses, g_losses
+
+
+def generator_loss(disc_outputs):
+    loss = 0
+    gen_losses = []
+    for dg in disc_outputs:
+        l = torch.mean((1 - dg) ** 2)
+        gen_losses.append(l)
+        loss += l
+
+    return loss, gen_losses
diff --git a/egs/ljspeech/TTS/matcha/hifigan/xutils.py b/egs/ljspeech/TTS/matcha/hifigan/xutils.py
new file mode 100644
index 0000000000..eefadcb7a1
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/hifigan/xutils.py
@@ -0,0 +1,60 @@
+""" from https://github.com/jik876/hifi-gan """
+
+import glob
+import os
+
+import matplotlib
+import torch
+from torch.nn.utils import weight_norm
+
+matplotlib.use("Agg")
+import matplotlib.pylab as plt
+
+
+def plot_spectrogram(spectrogram):
+    fig, ax = plt.subplots(figsize=(10, 2))
+    im = ax.imshow(spectrogram, aspect="auto", origin="lower", interpolation="none")
+    plt.colorbar(im, ax=ax)
+
+    fig.canvas.draw()
+    plt.close()
+
+    return fig
+
+
+def init_weights(m, mean=0.0, std=0.01):
+    classname = m.__class__.__name__
+    if classname.find("Conv") != -1:
+        m.weight.data.normal_(mean, std)
+
+
+def apply_weight_norm(m):
+    classname = m.__class__.__name__
+    if classname.find("Conv") != -1:
+        weight_norm(m)
+
+
+def get_padding(kernel_size, dilation=1):
+    return int((kernel_size * dilation - dilation) / 2)
+
+
+def load_checkpoint(filepath, device):
+    assert os.path.isfile(filepath)
+    print(f"Loading '{filepath}'")
+    checkpoint_dict = torch.load(filepath, map_location=device)
+    print("Complete.")
+    return checkpoint_dict
+
+
+def save_checkpoint(filepath, obj):
+    print(f"Saving checkpoint to {filepath}")
+    torch.save(obj, filepath)
+    print("Complete.")
+
+
+def scan_checkpoint(cp_dir, prefix):
+    pattern = os.path.join(cp_dir, prefix + "????????")
+    cp_list = glob.glob(pattern)
+    if len(cp_list) == 0:
+        return None
+    return sorted(cp_list)[-1]
diff --git a/egs/ljspeech/TTS/matcha/inference.py b/egs/ljspeech/TTS/matcha/inference.py
new file mode 100755
index 0000000000..64abd8e50b
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/inference.py
@@ -0,0 +1,199 @@
+#!/usr/bin/env python3
+# Copyright         2024  Xiaomi Corp.        (authors: Fangjun Kuang)
+
+import argparse
+import datetime as dt
+import json
+import logging
+from pathlib import Path
+
+import soundfile as sf
+import torch
+from matcha.hifigan.config import v1, v2, v3
+from matcha.hifigan.denoiser import Denoiser
+from matcha.hifigan.models import Generator as HiFiGAN
+from tokenizer import Tokenizer
+from train import get_model, get_params
+
+from icefall.checkpoint import load_checkpoint
+from icefall.utils import AttributeDict
+
+
+def get_parser():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter
+    )
+
+    parser.add_argument(
+        "--epoch",
+        type=int,
+        default=4000,
+        help="""It specifies the checkpoint to use for decoding.
+        Note: Epoch counts from 1.
+        """,
+    )
+
+    parser.add_argument(
+        "--exp-dir",
+        type=Path,
+        default="matcha/exp-new-3",
+        help="""The experiment dir.
+        It specifies the directory where all training related
+        files, e.g., checkpoints, log, etc, are saved
+        """,
+    )
+
+    parser.add_argument(
+        "--vocoder",
+        type=Path,
+        default="./generator_v1",
+        help="Path to the vocoder",
+    )
+
+    parser.add_argument(
+        "--tokens",
+        type=Path,
+        default="data/tokens.txt",
+    )
+
+    parser.add_argument(
+        "--cmvn",
+        type=str,
+        default="data/fbank/cmvn.json",
+        help="""Path to vocabulary.""",
+    )
+
+    parser.add_argument(
+        "--input-text",
+        type=str,
+        required=True,
+        help="The text to generate speech for",
+    )
+
+    parser.add_argument(
+        "--output-wav",
+        type=str,
+        required=True,
+        help="The filename of the wave to save the generated speech",
+    )
+
+    return parser
+
+
+def load_vocoder(checkpoint_path):
+    checkpoint_path = str(checkpoint_path)
+    if checkpoint_path.endswith("v1"):
+        h = AttributeDict(v1)
+    elif checkpoint_path.endswith("v2"):
+        h = AttributeDict(v2)
+    elif checkpoint_path.endswith("v3"):
+        h = AttributeDict(v3)
+    else:
+        raise ValueError(f"supports only v1, v2, and v3, given {checkpoint_path}")
+
+    hifigan = HiFiGAN(h).to("cpu")
+    hifigan.load_state_dict(
+        torch.load(checkpoint_path, map_location="cpu")["generator"]
+    )
+    _ = hifigan.eval()
+    hifigan.remove_weight_norm()
+    return hifigan
+
+
+def to_waveform(mel, vocoder, denoiser):
+    audio = vocoder(mel).clamp(-1, 1)
+    audio = denoiser(audio.squeeze(0), strength=0.00025).cpu().squeeze()
+    return audio.cpu().squeeze()
+
+
+def process_text(text: str, tokenizer):
+    x = tokenizer.texts_to_token_ids([text], add_sos=True, add_eos=True)
+    x = torch.tensor(x, dtype=torch.long)
+    x_lengths = torch.tensor([x.shape[-1]], dtype=torch.long, device="cpu")
+    return {"x_orig": text, "x": x, "x_lengths": x_lengths}
+
+
+def synthesise(
+    model, tokenizer, n_timesteps, text, length_scale, temperature, spks=None
+):
+    text_processed = process_text(text, tokenizer)
+    start_t = dt.datetime.now()
+    output = model.synthesise(
+        text_processed["x"],
+        text_processed["x_lengths"],
+        n_timesteps=n_timesteps,
+        temperature=temperature,
+        spks=spks,
+        length_scale=length_scale,
+    )
+    # merge everything to one dict
+    output.update({"start_t": start_t, **text_processed})
+    return output
+
+
+@torch.inference_mode()
+def main():
+    parser = get_parser()
+    args = parser.parse_args()
+    params = get_params()
+
+    params.update(vars(args))
+
+    tokenizer = Tokenizer(params.tokens)
+    params.blank_id = tokenizer.pad_id
+    params.vocab_size = tokenizer.vocab_size
+    params.model_args.n_vocab = params.vocab_size
+
+    with open(params.cmvn) as f:
+        stats = json.load(f)
+        params.data_args.data_statistics.mel_mean = stats["fbank_mean"]
+        params.data_args.data_statistics.mel_std = stats["fbank_std"]
+
+        params.model_args.data_statistics.mel_mean = stats["fbank_mean"]
+        params.model_args.data_statistics.mel_std = stats["fbank_std"]
+    logging.info(params)
+
+    logging.info("About to create model")
+    model = get_model(params)
+
+    if not Path(f"{params.exp_dir}/epoch-{params.epoch}.pt").is_file():
+        raise ValueError("{params.exp_dir}/epoch-{params.epoch}.pt does not exist")
+
+    load_checkpoint(f"{params.exp_dir}/epoch-{params.epoch}.pt", model)
+    model.eval()
+
+    if not Path(params.vocoder).is_file():
+        raise ValueError(f"{params.vocoder} does not exist")
+
+    vocoder = load_vocoder(params.vocoder)
+    denoiser = Denoiser(vocoder, mode="zeros")
+
+    # Number of ODE Solver steps
+    n_timesteps = 2
+
+    # Changes to the speaking rate
+    length_scale = 1.0
+
+    # Sampling temperature
+    temperature = 0.667
+
+    output = synthesise(
+        model=model,
+        tokenizer=tokenizer,
+        n_timesteps=n_timesteps,
+        text=params.input_text,
+        length_scale=length_scale,
+        temperature=temperature,
+    )
+    output["waveform"] = to_waveform(output["mel"], vocoder, denoiser)
+
+    sf.write(params.output_wav, output["waveform"], 22050, "PCM_16")
+
+
+if __name__ == "__main__":
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+    torch.set_num_threads(1)
+    torch.set_num_interop_threads(1)
+    main()
diff --git a/egs/ljspeech/TTS/matcha/model.py b/egs/ljspeech/TTS/matcha/model.py
new file mode 100644
index 0000000000..6539ffc24c
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/model.py
@@ -0,0 +1,97 @@
+# This file is copied from
+# https://github.com/shivammehta25/Matcha-TTS/blob/main/matcha/utils/model.py
+""" from https://github.com/jaywalnut310/glow-tts """
+
+import numpy as np
+import torch
+
+
+def sequence_mask(length, max_length=None):
+    if max_length is None:
+        max_length = length.max()
+    x = torch.arange(max_length, dtype=length.dtype, device=length.device)
+    return x.unsqueeze(0) < length.unsqueeze(1)
+
+
+def fix_len_compatibility(length, num_downsamplings_in_unet=2):
+    factor = torch.scalar_tensor(2).pow(num_downsamplings_in_unet)
+    length = (length / factor).ceil() * factor
+    if not torch.onnx.is_in_onnx_export():
+        return length.int().item()
+    else:
+        return length
+
+
+def convert_pad_shape(pad_shape):
+    inverted_shape = pad_shape[::-1]
+    pad_shape = [item for sublist in inverted_shape for item in sublist]
+    return pad_shape
+
+
+def generate_path(duration, mask):
+    device = duration.device
+
+    b, t_x, t_y = mask.shape
+    cum_duration = torch.cumsum(duration, 1)
+    path = torch.zeros(b, t_x, t_y, dtype=mask.dtype).to(device=device)
+
+    cum_duration_flat = cum_duration.view(b * t_x)
+    path = sequence_mask(cum_duration_flat, t_y).to(mask.dtype)
+    path = path.view(b, t_x, t_y)
+    path = (
+        path
+        - torch.nn.functional.pad(path, convert_pad_shape([[0, 0], [1, 0], [0, 0]]))[
+            :, :-1
+        ]
+    )
+    path = path * mask
+    return path
+
+
+def duration_loss(logw, logw_, lengths):
+    loss = torch.sum((logw - logw_) ** 2) / torch.sum(lengths)
+    return loss
+
+
+def normalize(data, mu, std):
+    if not isinstance(mu, (float, int)):
+        if isinstance(mu, list):
+            mu = torch.tensor(mu, dtype=data.dtype, device=data.device)
+        elif isinstance(mu, torch.Tensor):
+            mu = mu.to(data.device)
+        elif isinstance(mu, np.ndarray):
+            mu = torch.from_numpy(mu).to(data.device)
+        mu = mu.unsqueeze(-1)
+
+    if not isinstance(std, (float, int)):
+        if isinstance(std, list):
+            std = torch.tensor(std, dtype=data.dtype, device=data.device)
+        elif isinstance(std, torch.Tensor):
+            std = std.to(data.device)
+        elif isinstance(std, np.ndarray):
+            std = torch.from_numpy(std).to(data.device)
+        std = std.unsqueeze(-1)
+
+    return (data - mu) / std
+
+
+def denormalize(data, mu, std):
+    if not isinstance(mu, float):
+        if isinstance(mu, list):
+            mu = torch.tensor(mu, dtype=data.dtype, device=data.device)
+        elif isinstance(mu, torch.Tensor):
+            mu = mu.to(data.device)
+        elif isinstance(mu, np.ndarray):
+            mu = torch.from_numpy(mu).to(data.device)
+        mu = mu.unsqueeze(-1)
+
+    if not isinstance(std, float):
+        if isinstance(std, list):
+            std = torch.tensor(std, dtype=data.dtype, device=data.device)
+        elif isinstance(std, torch.Tensor):
+            std = std.to(data.device)
+        elif isinstance(std, np.ndarray):
+            std = torch.from_numpy(std).to(data.device)
+        std = std.unsqueeze(-1)
+
+    return data * std + mu
diff --git a/egs/ljspeech/TTS/matcha/models/README.md b/egs/ljspeech/TTS/matcha/models/README.md
new file mode 100644
index 0000000000..1099ef3c83
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/models/README.md
@@ -0,0 +1,3 @@
+# Introduction
+Files in this folder are copied from
+https://github.com/shivammehta25/Matcha-TTS/tree/main/matcha/models
diff --git a/egs/ljspeech/TTS/matcha/models/__init__.py b/egs/ljspeech/TTS/matcha/models/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/egs/ljspeech/TTS/matcha/models/components/__init__.py b/egs/ljspeech/TTS/matcha/models/components/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/egs/ljspeech/TTS/matcha/models/components/decoder.py b/egs/ljspeech/TTS/matcha/models/components/decoder.py
new file mode 100644
index 0000000000..14d19f5d4e
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/models/components/decoder.py
@@ -0,0 +1,459 @@
+import math
+from typing import Optional
+
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+from conformer import ConformerBlock
+from diffusers.models.activations import get_activation
+from einops import pack, rearrange, repeat
+from matcha.models.components.transformer import BasicTransformerBlock
+
+
+class SinusoidalPosEmb(torch.nn.Module):
+    def __init__(self, dim):
+        super().__init__()
+        self.dim = dim
+        assert self.dim % 2 == 0, "SinusoidalPosEmb requires dim to be even"
+
+    def forward(self, x, scale=1000):
+        if x.ndim < 1:
+            x = x.unsqueeze(0)
+        device = x.device
+        half_dim = self.dim // 2
+        emb = math.log(10000) / (half_dim - 1)
+        emb = torch.exp(torch.arange(half_dim, device=device).float() * -emb)
+        emb = scale * x.unsqueeze(1) * emb.unsqueeze(0)
+        emb = torch.cat((emb.sin(), emb.cos()), dim=-1)
+        return emb
+
+
+class Block1D(torch.nn.Module):
+    def __init__(self, dim, dim_out, groups=8):
+        super().__init__()
+        self.block = torch.nn.Sequential(
+            torch.nn.Conv1d(dim, dim_out, 3, padding=1),
+            torch.nn.GroupNorm(groups, dim_out),
+            nn.Mish(),
+        )
+
+    def forward(self, x, mask):
+        output = self.block(x * mask)
+        return output * mask
+
+
+class ResnetBlock1D(torch.nn.Module):
+    def __init__(self, dim, dim_out, time_emb_dim, groups=8):
+        super().__init__()
+        self.mlp = torch.nn.Sequential(
+            nn.Mish(), torch.nn.Linear(time_emb_dim, dim_out)
+        )
+
+        self.block1 = Block1D(dim, dim_out, groups=groups)
+        self.block2 = Block1D(dim_out, dim_out, groups=groups)
+
+        self.res_conv = torch.nn.Conv1d(dim, dim_out, 1)
+
+    def forward(self, x, mask, time_emb):
+        h = self.block1(x, mask)
+        h += self.mlp(time_emb).unsqueeze(-1)
+        h = self.block2(h, mask)
+        output = h + self.res_conv(x * mask)
+        return output
+
+
+class Downsample1D(nn.Module):
+    def __init__(self, dim):
+        super().__init__()
+        self.conv = torch.nn.Conv1d(dim, dim, 3, 2, 1)
+
+    def forward(self, x):
+        return self.conv(x)
+
+
+class TimestepEmbedding(nn.Module):
+    def __init__(
+        self,
+        in_channels: int,
+        time_embed_dim: int,
+        act_fn: str = "silu",
+        out_dim: int = None,
+        post_act_fn: Optional[str] = None,
+        cond_proj_dim=None,
+    ):
+        super().__init__()
+
+        self.linear_1 = nn.Linear(in_channels, time_embed_dim)
+
+        if cond_proj_dim is not None:
+            self.cond_proj = nn.Linear(cond_proj_dim, in_channels, bias=False)
+        else:
+            self.cond_proj = None
+
+        self.act = get_activation(act_fn)
+
+        if out_dim is not None:
+            time_embed_dim_out = out_dim
+        else:
+            time_embed_dim_out = time_embed_dim
+        self.linear_2 = nn.Linear(time_embed_dim, time_embed_dim_out)
+
+        if post_act_fn is None:
+            self.post_act = None
+        else:
+            self.post_act = get_activation(post_act_fn)
+
+    def forward(self, sample, condition=None):
+        if condition is not None:
+            sample = sample + self.cond_proj(condition)
+        sample = self.linear_1(sample)
+
+        if self.act is not None:
+            sample = self.act(sample)
+
+        sample = self.linear_2(sample)
+
+        if self.post_act is not None:
+            sample = self.post_act(sample)
+        return sample
+
+
+class Upsample1D(nn.Module):
+    """A 1D upsampling layer with an optional convolution.
+
+    Parameters:
+        channels (`int`):
+            number of channels in the inputs and outputs.
+        use_conv (`bool`, default `False`):
+            option to use a convolution.
+        use_conv_transpose (`bool`, default `False`):
+            option to use a convolution transpose.
+        out_channels (`int`, optional):
+            number of output channels. Defaults to `channels`.
+    """
+
+    def __init__(
+        self,
+        channels,
+        use_conv=False,
+        use_conv_transpose=True,
+        out_channels=None,
+        name="conv",
+    ):
+        super().__init__()
+        self.channels = channels
+        self.out_channels = out_channels or channels
+        self.use_conv = use_conv
+        self.use_conv_transpose = use_conv_transpose
+        self.name = name
+
+        self.conv = None
+        if use_conv_transpose:
+            self.conv = nn.ConvTranspose1d(channels, self.out_channels, 4, 2, 1)
+        elif use_conv:
+            self.conv = nn.Conv1d(self.channels, self.out_channels, 3, padding=1)
+
+    def forward(self, inputs):
+        assert inputs.shape[1] == self.channels
+        if self.use_conv_transpose:
+            return self.conv(inputs)
+
+        outputs = F.interpolate(inputs, scale_factor=2.0, mode="nearest")
+
+        if self.use_conv:
+            outputs = self.conv(outputs)
+
+        return outputs
+
+
+class ConformerWrapper(ConformerBlock):
+    def __init__(  # pylint: disable=useless-super-delegation
+        self,
+        *,
+        dim,
+        dim_head=64,
+        heads=8,
+        ff_mult=4,
+        conv_expansion_factor=2,
+        conv_kernel_size=31,
+        attn_dropout=0,
+        ff_dropout=0,
+        conv_dropout=0,
+        conv_causal=False,
+    ):
+        super().__init__(
+            dim=dim,
+            dim_head=dim_head,
+            heads=heads,
+            ff_mult=ff_mult,
+            conv_expansion_factor=conv_expansion_factor,
+            conv_kernel_size=conv_kernel_size,
+            attn_dropout=attn_dropout,
+            ff_dropout=ff_dropout,
+            conv_dropout=conv_dropout,
+            conv_causal=conv_causal,
+        )
+
+    def forward(
+        self,
+        hidden_states,
+        attention_mask,
+        encoder_hidden_states=None,
+        encoder_attention_mask=None,
+        timestep=None,
+    ):
+        return super().forward(x=hidden_states, mask=attention_mask.bool())
+
+
+class Decoder(nn.Module):
+    def __init__(
+        self,
+        in_channels,
+        out_channels,
+        channels=(256, 256),
+        dropout=0.05,
+        attention_head_dim=64,
+        n_blocks=1,
+        num_mid_blocks=2,
+        num_heads=4,
+        act_fn="snake",
+        down_block_type="transformer",
+        mid_block_type="transformer",
+        up_block_type="transformer",
+    ):
+        super().__init__()
+        channels = tuple(channels)
+        self.in_channels = in_channels
+        self.out_channels = out_channels
+
+        self.time_embeddings = SinusoidalPosEmb(in_channels)
+        time_embed_dim = channels[0] * 4
+        self.time_mlp = TimestepEmbedding(
+            in_channels=in_channels,
+            time_embed_dim=time_embed_dim,
+            act_fn="silu",
+        )
+
+        self.down_blocks = nn.ModuleList([])
+        self.mid_blocks = nn.ModuleList([])
+        self.up_blocks = nn.ModuleList([])
+
+        output_channel = in_channels
+        for i in range(len(channels)):  # pylint: disable=consider-using-enumerate
+            input_channel = output_channel
+            output_channel = channels[i]
+            is_last = i == len(channels) - 1
+            resnet = ResnetBlock1D(
+                dim=input_channel, dim_out=output_channel, time_emb_dim=time_embed_dim
+            )
+            transformer_blocks = nn.ModuleList(
+                [
+                    self.get_block(
+                        down_block_type,
+                        output_channel,
+                        attention_head_dim,
+                        num_heads,
+                        dropout,
+                        act_fn,
+                    )
+                    for _ in range(n_blocks)
+                ]
+            )
+            downsample = (
+                Downsample1D(output_channel)
+                if not is_last
+                else nn.Conv1d(output_channel, output_channel, 3, padding=1)
+            )
+
+            self.down_blocks.append(
+                nn.ModuleList([resnet, transformer_blocks, downsample])
+            )
+
+        for i in range(num_mid_blocks):
+            input_channel = channels[-1]
+            out_channels = channels[-1]
+
+            resnet = ResnetBlock1D(
+                dim=input_channel, dim_out=output_channel, time_emb_dim=time_embed_dim
+            )
+
+            transformer_blocks = nn.ModuleList(
+                [
+                    self.get_block(
+                        mid_block_type,
+                        output_channel,
+                        attention_head_dim,
+                        num_heads,
+                        dropout,
+                        act_fn,
+                    )
+                    for _ in range(n_blocks)
+                ]
+            )
+
+            self.mid_blocks.append(nn.ModuleList([resnet, transformer_blocks]))
+
+        channels = channels[::-1] + (channels[0],)
+        for i in range(len(channels) - 1):
+            input_channel = channels[i]
+            output_channel = channels[i + 1]
+            is_last = i == len(channels) - 2
+
+            resnet = ResnetBlock1D(
+                dim=2 * input_channel,
+                dim_out=output_channel,
+                time_emb_dim=time_embed_dim,
+            )
+            transformer_blocks = nn.ModuleList(
+                [
+                    self.get_block(
+                        up_block_type,
+                        output_channel,
+                        attention_head_dim,
+                        num_heads,
+                        dropout,
+                        act_fn,
+                    )
+                    for _ in range(n_blocks)
+                ]
+            )
+            upsample = (
+                Upsample1D(output_channel, use_conv_transpose=True)
+                if not is_last
+                else nn.Conv1d(output_channel, output_channel, 3, padding=1)
+            )
+
+            self.up_blocks.append(nn.ModuleList([resnet, transformer_blocks, upsample]))
+
+        self.final_block = Block1D(channels[-1], channels[-1])
+        self.final_proj = nn.Conv1d(channels[-1], self.out_channels, 1)
+
+        self.initialize_weights()
+        # nn.init.normal_(self.final_proj.weight)
+
+    @staticmethod
+    def get_block(block_type, dim, attention_head_dim, num_heads, dropout, act_fn):
+        if block_type == "conformer":
+            block = ConformerWrapper(
+                dim=dim,
+                dim_head=attention_head_dim,
+                heads=num_heads,
+                ff_mult=1,
+                conv_expansion_factor=2,
+                ff_dropout=dropout,
+                attn_dropout=dropout,
+                conv_dropout=dropout,
+                conv_kernel_size=31,
+            )
+        elif block_type == "transformer":
+            block = BasicTransformerBlock(
+                dim=dim,
+                num_attention_heads=num_heads,
+                attention_head_dim=attention_head_dim,
+                dropout=dropout,
+                activation_fn=act_fn,
+            )
+        else:
+            raise ValueError(f"Unknown block type {block_type}")
+
+        return block
+
+    def initialize_weights(self):
+        for m in self.modules():
+            if isinstance(m, nn.Conv1d):
+                nn.init.kaiming_normal_(m.weight, nonlinearity="relu")
+
+                if m.bias is not None:
+                    nn.init.constant_(m.bias, 0)
+
+            elif isinstance(m, nn.GroupNorm):
+                nn.init.constant_(m.weight, 1)
+                nn.init.constant_(m.bias, 0)
+
+            elif isinstance(m, nn.Linear):
+                nn.init.kaiming_normal_(m.weight, nonlinearity="relu")
+
+                if m.bias is not None:
+                    nn.init.constant_(m.bias, 0)
+
+    def forward(self, x, mask, mu, t, spks=None, cond=None):
+        """Forward pass of the UNet1DConditional model.
+
+        Args:
+            x (torch.Tensor): shape (batch_size, in_channels, time)
+            mask (_type_): shape (batch_size, 1, time)
+            t (_type_): shape (batch_size)
+            spks (_type_, optional): shape: (batch_size, condition_channels). Defaults to None.
+            cond (_type_, optional): placeholder for future use. Defaults to None.
+
+        Raises:
+            ValueError: _description_
+            ValueError: _description_
+
+        Returns:
+            _type_: _description_
+        """
+
+        t = self.time_embeddings(t)
+        t = self.time_mlp(t)
+
+        x = pack([x, mu], "b * t")[0]
+
+        if spks is not None:
+            spks = repeat(spks, "b c -> b c t", t=x.shape[-1])
+            x = pack([x, spks], "b * t")[0]
+
+        hiddens = []
+        masks = [mask]
+        for resnet, transformer_blocks, downsample in self.down_blocks:
+            mask_down = masks[-1]
+            x = resnet(x, mask_down, t)
+            x = rearrange(x, "b c t -> b t c")
+            mask_down = rearrange(mask_down, "b 1 t -> b t")
+            for transformer_block in transformer_blocks:
+                x = transformer_block(
+                    hidden_states=x,
+                    attention_mask=mask_down,
+                    timestep=t,
+                )
+            x = rearrange(x, "b t c -> b c t")
+            mask_down = rearrange(mask_down, "b t -> b 1 t")
+            hiddens.append(x)  # Save hidden states for skip connections
+            x = downsample(x * mask_down)
+            masks.append(mask_down[:, :, ::2])
+
+        masks = masks[:-1]
+        mask_mid = masks[-1]
+
+        for resnet, transformer_blocks in self.mid_blocks:
+            x = resnet(x, mask_mid, t)
+            x = rearrange(x, "b c t -> b t c")
+            mask_mid = rearrange(mask_mid, "b 1 t -> b t")
+            for transformer_block in transformer_blocks:
+                x = transformer_block(
+                    hidden_states=x,
+                    attention_mask=mask_mid,
+                    timestep=t,
+                )
+            x = rearrange(x, "b t c -> b c t")
+            mask_mid = rearrange(mask_mid, "b t -> b 1 t")
+
+        for resnet, transformer_blocks, upsample in self.up_blocks:
+            mask_up = masks.pop()
+            x = resnet(pack([x, hiddens.pop()], "b * t")[0], mask_up, t)
+            x = rearrange(x, "b c t -> b t c")
+            mask_up = rearrange(mask_up, "b 1 t -> b t")
+            for transformer_block in transformer_blocks:
+                x = transformer_block(
+                    hidden_states=x,
+                    attention_mask=mask_up,
+                    timestep=t,
+                )
+            x = rearrange(x, "b t c -> b c t")
+            mask_up = rearrange(mask_up, "b t -> b 1 t")
+            x = upsample(x * mask_up)
+
+        x = self.final_block(x, mask_up)
+        output = self.final_proj(x * mask_up)
+
+        return output * mask
diff --git a/egs/ljspeech/TTS/matcha/models/components/flow_matching.py b/egs/ljspeech/TTS/matcha/models/components/flow_matching.py
new file mode 100644
index 0000000000..997689b1cb
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/models/components/flow_matching.py
@@ -0,0 +1,140 @@
+from abc import ABC
+
+import torch
+import torch.nn.functional as F
+from matcha.models.components.decoder import Decoder
+
+
+class BASECFM(torch.nn.Module, ABC):
+    def __init__(
+        self,
+        n_feats,
+        cfm_params,
+        n_spks=1,
+        spk_emb_dim=128,
+    ):
+        super().__init__()
+        self.n_feats = n_feats
+        self.n_spks = n_spks
+        self.spk_emb_dim = spk_emb_dim
+        self.solver = cfm_params.solver
+        if hasattr(cfm_params, "sigma_min"):
+            self.sigma_min = cfm_params.sigma_min
+        else:
+            self.sigma_min = 1e-4
+
+        self.estimator = None
+
+    @torch.inference_mode()
+    def forward(self, mu, mask, n_timesteps, temperature=1.0, spks=None, cond=None):
+        """Forward diffusion
+
+        Args:
+            mu (torch.Tensor): output of encoder
+                shape: (batch_size, n_feats, mel_timesteps)
+            mask (torch.Tensor): output_mask
+                shape: (batch_size, 1, mel_timesteps)
+            n_timesteps (int): number of diffusion steps
+            temperature (float, optional): temperature for scaling noise. Defaults to 1.0.
+            spks (torch.Tensor, optional): speaker ids. Defaults to None.
+                shape: (batch_size, spk_emb_dim)
+            cond: Not used but kept for future purposes
+
+        Returns:
+            sample: generated mel-spectrogram
+                shape: (batch_size, n_feats, mel_timesteps)
+        """
+        z = torch.randn_like(mu) * temperature
+        t_span = torch.linspace(0, 1, n_timesteps + 1, device=mu.device)
+        return self.solve_euler(
+            z, t_span=t_span, mu=mu, mask=mask, spks=spks, cond=cond
+        )
+
+    def solve_euler(self, x, t_span, mu, mask, spks, cond):
+        """
+        Fixed euler solver for ODEs.
+        Args:
+            x (torch.Tensor): random noise
+            t_span (torch.Tensor): n_timesteps interpolated
+                shape: (n_timesteps + 1,)
+            mu (torch.Tensor): output of encoder
+                shape: (batch_size, n_feats, mel_timesteps)
+            mask (torch.Tensor): output_mask
+                shape: (batch_size, 1, mel_timesteps)
+            spks (torch.Tensor, optional): speaker ids. Defaults to None.
+                shape: (batch_size, spk_emb_dim)
+            cond: Not used but kept for future purposes
+        """
+        t, _, dt = t_span[0], t_span[-1], t_span[1] - t_span[0]
+
+        # I am storing this because I can later plot it by putting a debugger here and saving it to a file
+        # Or in future might add like a return_all_steps flag
+        sol = []
+
+        for step in range(1, len(t_span)):
+            dphi_dt = self.estimator(x, mask, mu, t, spks, cond)
+
+            x = x + dt * dphi_dt
+            t = t + dt
+            sol.append(x)
+            if step < len(t_span) - 1:
+                dt = t_span[step + 1] - t
+
+        return sol[-1]
+
+    def compute_loss(self, x1, mask, mu, spks=None, cond=None):
+        """Computes diffusion loss
+
+        Args:
+            x1 (torch.Tensor): Target
+                shape: (batch_size, n_feats, mel_timesteps)
+            mask (torch.Tensor): target mask
+                shape: (batch_size, 1, mel_timesteps)
+            mu (torch.Tensor): output of encoder
+                shape: (batch_size, n_feats, mel_timesteps)
+            spks (torch.Tensor, optional): speaker embedding. Defaults to None.
+                shape: (batch_size, spk_emb_dim)
+
+        Returns:
+            loss: conditional flow matching loss
+            y: conditional flow
+                shape: (batch_size, n_feats, mel_timesteps)
+        """
+        b, _, t = mu.shape
+
+        # random timestep
+        t = torch.rand([b, 1, 1], device=mu.device, dtype=mu.dtype)
+        # sample noise p(x_0)
+        z = torch.randn_like(x1)
+
+        y = (1 - (1 - self.sigma_min) * t) * z + t * x1
+        u = x1 - (1 - self.sigma_min) * z
+
+        loss = F.mse_loss(
+            self.estimator(y, mask, mu, t.squeeze(), spks), u, reduction="sum"
+        ) / (torch.sum(mask) * u.shape[1])
+        return loss, y
+
+
+class CFM(BASECFM):
+    def __init__(
+        self,
+        in_channels,
+        out_channel,
+        cfm_params,
+        decoder_params,
+        n_spks=1,
+        spk_emb_dim=64,
+    ):
+        super().__init__(
+            n_feats=in_channels,
+            cfm_params=cfm_params,
+            n_spks=n_spks,
+            spk_emb_dim=spk_emb_dim,
+        )
+
+        in_channels = in_channels + (spk_emb_dim if n_spks > 1 else 0)
+        # Just change the architecture of the estimator here
+        self.estimator = Decoder(
+            in_channels=in_channels, out_channels=out_channel, **decoder_params
+        )
diff --git a/egs/ljspeech/TTS/matcha/models/components/text_encoder.py b/egs/ljspeech/TTS/matcha/models/components/text_encoder.py
new file mode 100644
index 0000000000..ca77cba51c
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/models/components/text_encoder.py
@@ -0,0 +1,447 @@
+""" from https://github.com/jaywalnut310/glow-tts """
+
+import math
+
+import torch
+import torch.nn as nn
+from einops import rearrange
+from matcha.model import sequence_mask
+
+
+class LayerNorm(nn.Module):
+    def __init__(self, channels, eps=1e-4):
+        super().__init__()
+        self.channels = channels
+        self.eps = eps
+
+        self.gamma = torch.nn.Parameter(torch.ones(channels))
+        self.beta = torch.nn.Parameter(torch.zeros(channels))
+
+    def forward(self, x):
+        n_dims = len(x.shape)
+        mean = torch.mean(x, 1, keepdim=True)
+        variance = torch.mean((x - mean) ** 2, 1, keepdim=True)
+
+        x = (x - mean) * torch.rsqrt(variance + self.eps)
+
+        shape = [1, -1] + [1] * (n_dims - 2)
+        x = x * self.gamma.view(*shape) + self.beta.view(*shape)
+        return x
+
+
+class ConvReluNorm(nn.Module):
+    def __init__(
+        self,
+        in_channels,
+        hidden_channels,
+        out_channels,
+        kernel_size,
+        n_layers,
+        p_dropout,
+    ):
+        super().__init__()
+        self.in_channels = in_channels
+        self.hidden_channels = hidden_channels
+        self.out_channels = out_channels
+        self.kernel_size = kernel_size
+        self.n_layers = n_layers
+        self.p_dropout = p_dropout
+
+        self.conv_layers = torch.nn.ModuleList()
+        self.norm_layers = torch.nn.ModuleList()
+        self.conv_layers.append(
+            torch.nn.Conv1d(
+                in_channels, hidden_channels, kernel_size, padding=kernel_size // 2
+            )
+        )
+        self.norm_layers.append(LayerNorm(hidden_channels))
+        self.relu_drop = torch.nn.Sequential(
+            torch.nn.ReLU(), torch.nn.Dropout(p_dropout)
+        )
+        for _ in range(n_layers - 1):
+            self.conv_layers.append(
+                torch.nn.Conv1d(
+                    hidden_channels,
+                    hidden_channels,
+                    kernel_size,
+                    padding=kernel_size // 2,
+                )
+            )
+            self.norm_layers.append(LayerNorm(hidden_channels))
+        self.proj = torch.nn.Conv1d(hidden_channels, out_channels, 1)
+        self.proj.weight.data.zero_()
+        self.proj.bias.data.zero_()
+
+    def forward(self, x, x_mask):
+        x_org = x
+        for i in range(self.n_layers):
+            x = self.conv_layers[i](x * x_mask)
+            x = self.norm_layers[i](x)
+            x = self.relu_drop(x)
+        x = x_org + self.proj(x)
+        return x * x_mask
+
+
+class DurationPredictor(nn.Module):
+    def __init__(self, in_channels, filter_channels, kernel_size, p_dropout):
+        super().__init__()
+        self.in_channels = in_channels
+        self.filter_channels = filter_channels
+        self.p_dropout = p_dropout
+
+        self.drop = torch.nn.Dropout(p_dropout)
+        self.conv_1 = torch.nn.Conv1d(
+            in_channels, filter_channels, kernel_size, padding=kernel_size // 2
+        )
+        self.norm_1 = LayerNorm(filter_channels)
+        self.conv_2 = torch.nn.Conv1d(
+            filter_channels, filter_channels, kernel_size, padding=kernel_size // 2
+        )
+        self.norm_2 = LayerNorm(filter_channels)
+        self.proj = torch.nn.Conv1d(filter_channels, 1, 1)
+
+    def forward(self, x, x_mask):
+        x = self.conv_1(x * x_mask)
+        x = torch.relu(x)
+        x = self.norm_1(x)
+        x = self.drop(x)
+        x = self.conv_2(x * x_mask)
+        x = torch.relu(x)
+        x = self.norm_2(x)
+        x = self.drop(x)
+        x = self.proj(x * x_mask)
+        return x * x_mask
+
+
+class RotaryPositionalEmbeddings(nn.Module):
+    """
+    ## RoPE module
+
+    Rotary encoding transforms pairs of features by rotating in the 2D plane.
+    That is, it organizes the $d$ features as $\frac{d}{2}$ pairs.
+    Each pair can be considered a coordinate in a 2D plane, and the encoding will rotate it
+    by an angle depending on the position of the token.
+    """
+
+    def __init__(self, d: int, base: int = 10_000):
+        r"""
+        * `d` is the number of features $d$
+        * `base` is the constant used for calculating $\Theta$
+        """
+        super().__init__()
+
+        self.base = base
+        self.d = int(d)
+        self.cos_cached = None
+        self.sin_cached = None
+
+    def _build_cache(self, x: torch.Tensor):
+        r"""
+        Cache $\cos$ and $\sin$ values
+        """
+        # Return if cache is already built
+        if self.cos_cached is not None and x.shape[0] <= self.cos_cached.shape[0]:
+            return
+
+        # Get sequence length
+        seq_len = x.shape[0]
+
+        # $\Theta = {\theta_i = 10000^{-\frac{2(i-1)}{d}}, i \in [1, 2, ..., \frac{d}{2}]}$
+        theta = 1.0 / (self.base ** (torch.arange(0, self.d, 2).float() / self.d)).to(
+            x.device
+        )
+
+        # Create position indexes `[0, 1, ..., seq_len - 1]`
+        seq_idx = torch.arange(seq_len, device=x.device).float().to(x.device)
+
+        # Calculate the product of position index and $\theta_i$
+        idx_theta = torch.einsum("n,d->nd", seq_idx, theta)
+
+        # Concatenate so that for row $m$ we have
+        # $[m \theta_0, m \theta_1, ..., m \theta_{\frac{d}{2}}, m \theta_0, m \theta_1, ..., m \theta_{\frac{d}{2}}]$
+        idx_theta2 = torch.cat([idx_theta, idx_theta], dim=1)
+
+        # Cache them
+        self.cos_cached = idx_theta2.cos()[:, None, None, :]
+        self.sin_cached = idx_theta2.sin()[:, None, None, :]
+
+    def _neg_half(self, x: torch.Tensor):
+        # $\frac{d}{2}$
+        d_2 = self.d // 2
+
+        # Calculate $[-x^{(\frac{d}{2} + 1)}, -x^{(\frac{d}{2} + 2)}, ..., -x^{(d)}, x^{(1)}, x^{(2)}, ..., x^{(\frac{d}{2})}]$
+        return torch.cat([-x[:, :, :, d_2:], x[:, :, :, :d_2]], dim=-1)
+
+    def forward(self, x: torch.Tensor):
+        """
+        * `x` is the Tensor at the head of a key or a query with shape `[seq_len, batch_size, n_heads, d]`
+        """
+        # Cache $\cos$ and $\sin$ values
+        x = rearrange(x, "b h t d -> t b h d")
+
+        self._build_cache(x)
+
+        # Split the features, we can choose to apply rotary embeddings only to a partial set of features.
+        x_rope, x_pass = x[..., : self.d], x[..., self.d :]
+
+        # Calculate
+        # $[-x^{(\frac{d}{2} + 1)}, -x^{(\frac{d}{2} + 2)}, ..., -x^{(d)}, x^{(1)}, x^{(2)}, ..., x^{(\frac{d}{2})}]$
+        neg_half_x = self._neg_half(x_rope)
+
+        x_rope = (x_rope * self.cos_cached[: x.shape[0]]) + (
+            neg_half_x * self.sin_cached[: x.shape[0]]
+        )
+
+        return rearrange(torch.cat((x_rope, x_pass), dim=-1), "t b h d -> b h t d")
+
+
+class MultiHeadAttention(nn.Module):
+    def __init__(
+        self,
+        channels,
+        out_channels,
+        n_heads,
+        heads_share=True,
+        p_dropout=0.0,
+        proximal_bias=False,
+        proximal_init=False,
+    ):
+        super().__init__()
+        assert channels % n_heads == 0
+
+        self.channels = channels
+        self.out_channels = out_channels
+        self.n_heads = n_heads
+        self.heads_share = heads_share
+        self.proximal_bias = proximal_bias
+        self.p_dropout = p_dropout
+        self.attn = None
+
+        self.k_channels = channels // n_heads
+        self.conv_q = torch.nn.Conv1d(channels, channels, 1)
+        self.conv_k = torch.nn.Conv1d(channels, channels, 1)
+        self.conv_v = torch.nn.Conv1d(channels, channels, 1)
+
+        # from https://nn.labml.ai/transformers/rope/index.html
+        self.query_rotary_pe = RotaryPositionalEmbeddings(self.k_channels * 0.5)
+        self.key_rotary_pe = RotaryPositionalEmbeddings(self.k_channels * 0.5)
+
+        self.conv_o = torch.nn.Conv1d(channels, out_channels, 1)
+        self.drop = torch.nn.Dropout(p_dropout)
+
+        torch.nn.init.xavier_uniform_(self.conv_q.weight)
+        torch.nn.init.xavier_uniform_(self.conv_k.weight)
+        if proximal_init:
+            self.conv_k.weight.data.copy_(self.conv_q.weight.data)
+            self.conv_k.bias.data.copy_(self.conv_q.bias.data)
+        torch.nn.init.xavier_uniform_(self.conv_v.weight)
+
+    def forward(self, x, c, attn_mask=None):
+        q = self.conv_q(x)
+        k = self.conv_k(c)
+        v = self.conv_v(c)
+
+        x, self.attn = self.attention(q, k, v, mask=attn_mask)
+
+        x = self.conv_o(x)
+        return x
+
+    def attention(self, query, key, value, mask=None):
+        b, d, t_s, t_t = (*key.size(), query.size(2))
+        query = rearrange(query, "b (h c) t-> b h t c", h=self.n_heads)
+        key = rearrange(key, "b (h c) t-> b h t c", h=self.n_heads)
+        value = rearrange(value, "b (h c) t-> b h t c", h=self.n_heads)
+
+        query = self.query_rotary_pe(query)
+        key = self.key_rotary_pe(key)
+
+        scores = torch.matmul(query, key.transpose(-2, -1)) / math.sqrt(self.k_channels)
+
+        if self.proximal_bias:
+            assert t_s == t_t, "Proximal bias is only available for self-attention."
+            scores = scores + self._attention_bias_proximal(t_s).to(
+                device=scores.device, dtype=scores.dtype
+            )
+        if mask is not None:
+            scores = scores.masked_fill(mask == 0, -1e4)
+        p_attn = torch.nn.functional.softmax(scores, dim=-1)
+        p_attn = self.drop(p_attn)
+        output = torch.matmul(p_attn, value)
+        output = output.transpose(2, 3).contiguous().view(b, d, t_t)
+        return output, p_attn
+
+    @staticmethod
+    def _attention_bias_proximal(length):
+        r = torch.arange(length, dtype=torch.float32)
+        diff = torch.unsqueeze(r, 0) - torch.unsqueeze(r, 1)
+        return torch.unsqueeze(torch.unsqueeze(-torch.log1p(torch.abs(diff)), 0), 0)
+
+
+class FFN(nn.Module):
+    def __init__(
+        self, in_channels, out_channels, filter_channels, kernel_size, p_dropout=0.0
+    ):
+        super().__init__()
+        self.in_channels = in_channels
+        self.out_channels = out_channels
+        self.filter_channels = filter_channels
+        self.kernel_size = kernel_size
+        self.p_dropout = p_dropout
+
+        self.conv_1 = torch.nn.Conv1d(
+            in_channels, filter_channels, kernel_size, padding=kernel_size // 2
+        )
+        self.conv_2 = torch.nn.Conv1d(
+            filter_channels, out_channels, kernel_size, padding=kernel_size // 2
+        )
+        self.drop = torch.nn.Dropout(p_dropout)
+
+    def forward(self, x, x_mask):
+        x = self.conv_1(x * x_mask)
+        x = torch.relu(x)
+        x = self.drop(x)
+        x = self.conv_2(x * x_mask)
+        return x * x_mask
+
+
+class Encoder(nn.Module):
+    def __init__(
+        self,
+        hidden_channels,
+        filter_channels,
+        n_heads,
+        n_layers,
+        kernel_size=1,
+        p_dropout=0.0,
+        **kwargs,
+    ):
+        super().__init__()
+        self.hidden_channels = hidden_channels
+        self.filter_channels = filter_channels
+        self.n_heads = n_heads
+        self.n_layers = n_layers
+        self.kernel_size = kernel_size
+        self.p_dropout = p_dropout
+
+        self.drop = torch.nn.Dropout(p_dropout)
+        self.attn_layers = torch.nn.ModuleList()
+        self.norm_layers_1 = torch.nn.ModuleList()
+        self.ffn_layers = torch.nn.ModuleList()
+        self.norm_layers_2 = torch.nn.ModuleList()
+        for _ in range(self.n_layers):
+            self.attn_layers.append(
+                MultiHeadAttention(
+                    hidden_channels, hidden_channels, n_heads, p_dropout=p_dropout
+                )
+            )
+            self.norm_layers_1.append(LayerNorm(hidden_channels))
+            self.ffn_layers.append(
+                FFN(
+                    hidden_channels,
+                    hidden_channels,
+                    filter_channels,
+                    kernel_size,
+                    p_dropout=p_dropout,
+                )
+            )
+            self.norm_layers_2.append(LayerNorm(hidden_channels))
+
+    def forward(self, x, x_mask):
+        attn_mask = x_mask.unsqueeze(2) * x_mask.unsqueeze(-1)
+        for i in range(self.n_layers):
+            x = x * x_mask
+            y = self.attn_layers[i](x, x, attn_mask)
+            y = self.drop(y)
+            x = self.norm_layers_1[i](x + y)
+            y = self.ffn_layers[i](x, x_mask)
+            y = self.drop(y)
+            x = self.norm_layers_2[i](x + y)
+        x = x * x_mask
+        return x
+
+
+class TextEncoder(nn.Module):
+    def __init__(
+        self,
+        encoder_type,
+        encoder_params,
+        duration_predictor_params,
+        n_vocab,
+        n_spks=1,
+        spk_emb_dim=128,
+    ):
+        super().__init__()
+        self.encoder_type = encoder_type
+        self.n_vocab = n_vocab
+        self.n_feats = encoder_params.n_feats
+        self.n_channels = encoder_params.n_channels
+        self.spk_emb_dim = spk_emb_dim
+        self.n_spks = n_spks
+
+        self.emb = torch.nn.Embedding(n_vocab, self.n_channels)
+        torch.nn.init.normal_(self.emb.weight, 0.0, self.n_channels**-0.5)
+
+        if encoder_params.prenet:
+            self.prenet = ConvReluNorm(
+                self.n_channels,
+                self.n_channels,
+                self.n_channels,
+                kernel_size=5,
+                n_layers=3,
+                p_dropout=0.5,
+            )
+        else:
+            self.prenet = lambda x, x_mask: x
+
+        self.encoder = Encoder(
+            encoder_params.n_channels + (spk_emb_dim if n_spks > 1 else 0),
+            encoder_params.filter_channels,
+            encoder_params.n_heads,
+            encoder_params.n_layers,
+            encoder_params.kernel_size,
+            encoder_params.p_dropout,
+        )
+
+        self.proj_m = torch.nn.Conv1d(
+            self.n_channels + (spk_emb_dim if n_spks > 1 else 0), self.n_feats, 1
+        )
+        self.proj_w = DurationPredictor(
+            self.n_channels + (spk_emb_dim if n_spks > 1 else 0),
+            duration_predictor_params.filter_channels_dp,
+            duration_predictor_params.kernel_size,
+            duration_predictor_params.p_dropout,
+        )
+
+    def forward(self, x, x_lengths, spks=None):
+        """Run forward pass to the transformer based encoder and duration predictor
+
+        Args:
+            x (torch.Tensor): text input
+                shape: (batch_size, max_text_length)
+            x_lengths (torch.Tensor): text input lengths
+                shape: (batch_size,)
+            spks (torch.Tensor, optional): speaker ids. Defaults to None.
+                shape: (batch_size,)
+
+        Returns:
+            mu (torch.Tensor): average output of the encoder
+                shape: (batch_size, n_feats, max_text_length)
+            logw (torch.Tensor): log duration predicted by the duration predictor
+                shape: (batch_size, 1, max_text_length)
+            x_mask (torch.Tensor): mask for the text input
+                shape: (batch_size, 1, max_text_length)
+        """
+        x = self.emb(x) * math.sqrt(self.n_channels)
+        x = torch.transpose(x, 1, -1)
+        x_mask = torch.unsqueeze(sequence_mask(x_lengths, x.size(2)), 1).to(x.dtype)
+
+        x = self.prenet(x, x_mask)
+        if self.n_spks > 1:
+            x = torch.cat([x, spks.unsqueeze(-1).repeat(1, 1, x.shape[-1])], dim=1)
+        x = self.encoder(x, x_mask)
+        mu = self.proj_m(x) * x_mask
+
+        x_dp = torch.detach(x)
+        logw = self.proj_w(x_dp, x_mask)
+
+        return mu, logw, x_mask
diff --git a/egs/ljspeech/TTS/matcha/models/components/transformer.py b/egs/ljspeech/TTS/matcha/models/components/transformer.py
new file mode 100644
index 0000000000..a82e560bca
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/models/components/transformer.py
@@ -0,0 +1,353 @@
+from typing import Any, Dict, Optional
+
+import torch
+import torch.nn as nn
+from diffusers.models.attention import (
+    GEGLU,
+    GELU,
+    AdaLayerNorm,
+    AdaLayerNormZero,
+    ApproximateGELU,
+)
+from diffusers.models.attention_processor import Attention
+from diffusers.models.lora import LoRACompatibleLinear
+from diffusers.utils.torch_utils import maybe_allow_in_graph
+
+
+class SnakeBeta(nn.Module):
+    """
+    A modified Snake function which uses separate parameters for the magnitude of the periodic components
+    Shape:
+        - Input: (B, C, T)
+        - Output: (B, C, T), same shape as the input
+    Parameters:
+        - alpha - trainable parameter that controls frequency
+        - beta - trainable parameter that controls magnitude
+    References:
+        - This activation function is a modified version based on this paper by Liu Ziyin, Tilman Hartwig, Masahito Ueda:
+        https://arxiv.org/abs/2006.08195
+    Examples:
+        >>> a1 = snakebeta(256)
+        >>> x = torch.randn(256)
+        >>> x = a1(x)
+    """
+
+    def __init__(
+        self,
+        in_features,
+        out_features,
+        alpha=1.0,
+        alpha_trainable=True,
+        alpha_logscale=True,
+    ):
+        """
+        Initialization.
+        INPUT:
+            - in_features: shape of the input
+            - alpha - trainable parameter that controls frequency
+            - beta - trainable parameter that controls magnitude
+            alpha is initialized to 1 by default, higher values = higher-frequency.
+            beta is initialized to 1 by default, higher values = higher-magnitude.
+            alpha will be trained along with the rest of your model.
+        """
+        super().__init__()
+        self.in_features = (
+            out_features if isinstance(out_features, list) else [out_features]
+        )
+        self.proj = LoRACompatibleLinear(in_features, out_features)
+
+        # initialize alpha
+        self.alpha_logscale = alpha_logscale
+        if self.alpha_logscale:  # log scale alphas initialized to zeros
+            self.alpha = nn.Parameter(torch.zeros(self.in_features) * alpha)
+            self.beta = nn.Parameter(torch.zeros(self.in_features) * alpha)
+        else:  # linear scale alphas initialized to ones
+            self.alpha = nn.Parameter(torch.ones(self.in_features) * alpha)
+            self.beta = nn.Parameter(torch.ones(self.in_features) * alpha)
+
+        self.alpha.requires_grad = alpha_trainable
+        self.beta.requires_grad = alpha_trainable
+
+        self.no_div_by_zero = 0.000000001
+
+    def forward(self, x):
+        """
+        Forward pass of the function.
+        Applies the function to the input elementwise.
+        SnakeBeta ∶= x + 1/b * sin^2 (xa)
+        """
+        x = self.proj(x)
+        if self.alpha_logscale:
+            alpha = torch.exp(self.alpha)
+            beta = torch.exp(self.beta)
+        else:
+            alpha = self.alpha
+            beta = self.beta
+
+        x = x + (1.0 / (beta + self.no_div_by_zero)) * torch.pow(
+            torch.sin(x * alpha), 2
+        )
+
+        return x
+
+
+class FeedForward(nn.Module):
+    r"""
+    A feed-forward layer.
+
+    Parameters:
+        dim (`int`): The number of channels in the input.
+        dim_out (`int`, *optional*): The number of channels in the output. If not given, defaults to `dim`.
+        mult (`int`, *optional*, defaults to 4): The multiplier to use for the hidden dimension.
+        dropout (`float`, *optional*, defaults to 0.0): The dropout probability to use.
+        activation_fn (`str`, *optional*, defaults to `"geglu"`): Activation function to be used in feed-forward.
+        final_dropout (`bool` *optional*, defaults to False): Apply a final dropout.
+    """
+
+    def __init__(
+        self,
+        dim: int,
+        dim_out: Optional[int] = None,
+        mult: int = 4,
+        dropout: float = 0.0,
+        activation_fn: str = "geglu",
+        final_dropout: bool = False,
+    ):
+        super().__init__()
+        inner_dim = int(dim * mult)
+        dim_out = dim_out if dim_out is not None else dim
+
+        if activation_fn == "gelu":
+            act_fn = GELU(dim, inner_dim)
+        if activation_fn == "gelu-approximate":
+            act_fn = GELU(dim, inner_dim, approximate="tanh")
+        elif activation_fn == "geglu":
+            act_fn = GEGLU(dim, inner_dim)
+        elif activation_fn == "geglu-approximate":
+            act_fn = ApproximateGELU(dim, inner_dim)
+        elif activation_fn == "snakebeta":
+            act_fn = SnakeBeta(dim, inner_dim)
+
+        self.net = nn.ModuleList([])
+        # project in
+        self.net.append(act_fn)
+        # project dropout
+        self.net.append(nn.Dropout(dropout))
+        # project out
+        self.net.append(LoRACompatibleLinear(inner_dim, dim_out))
+        # FF as used in Vision Transformer, MLP-Mixer, etc. have a final dropout
+        if final_dropout:
+            self.net.append(nn.Dropout(dropout))
+
+    def forward(self, hidden_states):
+        for module in self.net:
+            hidden_states = module(hidden_states)
+        return hidden_states
+
+
+@maybe_allow_in_graph
+class BasicTransformerBlock(nn.Module):
+    r"""
+    A basic Transformer block.
+
+    Parameters:
+        dim (`int`): The number of channels in the input and output.
+        num_attention_heads (`int`): The number of heads to use for multi-head attention.
+        attention_head_dim (`int`): The number of channels in each head.
+        dropout (`float`, *optional*, defaults to 0.0): The dropout probability to use.
+        cross_attention_dim (`int`, *optional*): The size of the encoder_hidden_states vector for cross attention.
+        only_cross_attention (`bool`, *optional*):
+            Whether to use only cross-attention layers. In this case two cross attention layers are used.
+        double_self_attention (`bool`, *optional*):
+            Whether to use two self-attention layers. In this case no cross attention layers are used.
+        activation_fn (`str`, *optional*, defaults to `"geglu"`): Activation function to be used in feed-forward.
+        num_embeds_ada_norm (:
+            obj: `int`, *optional*): The number of diffusion steps used during training. See `Transformer2DModel`.
+        attention_bias (:
+            obj: `bool`, *optional*, defaults to `False`): Configure if the attentions should contain a bias parameter.
+    """
+
+    def __init__(
+        self,
+        dim: int,
+        num_attention_heads: int,
+        attention_head_dim: int,
+        dropout=0.0,
+        cross_attention_dim: Optional[int] = None,
+        activation_fn: str = "geglu",
+        num_embeds_ada_norm: Optional[int] = None,
+        attention_bias: bool = False,
+        only_cross_attention: bool = False,
+        double_self_attention: bool = False,
+        upcast_attention: bool = False,
+        norm_elementwise_affine: bool = True,
+        norm_type: str = "layer_norm",
+        final_dropout: bool = False,
+    ):
+        super().__init__()
+        self.only_cross_attention = only_cross_attention
+
+        self.use_ada_layer_norm_zero = (
+            num_embeds_ada_norm is not None
+        ) and norm_type == "ada_norm_zero"
+        self.use_ada_layer_norm = (
+            num_embeds_ada_norm is not None
+        ) and norm_type == "ada_norm"
+
+        if norm_type in ("ada_norm", "ada_norm_zero") and num_embeds_ada_norm is None:
+            raise ValueError(
+                f"`norm_type` is set to {norm_type}, but `num_embeds_ada_norm` is not defined. Please make sure to"
+                f" define `num_embeds_ada_norm` if setting `norm_type` to {norm_type}."
+            )
+
+        # Define 3 blocks. Each block has its own normalization layer.
+        # 1. Self-Attn
+        if self.use_ada_layer_norm:
+            self.norm1 = AdaLayerNorm(dim, num_embeds_ada_norm)
+        elif self.use_ada_layer_norm_zero:
+            self.norm1 = AdaLayerNormZero(dim, num_embeds_ada_norm)
+        else:
+            self.norm1 = nn.LayerNorm(dim, elementwise_affine=norm_elementwise_affine)
+        self.attn1 = Attention(
+            query_dim=dim,
+            heads=num_attention_heads,
+            dim_head=attention_head_dim,
+            dropout=dropout,
+            bias=attention_bias,
+            cross_attention_dim=cross_attention_dim if only_cross_attention else None,
+            upcast_attention=upcast_attention,
+        )
+
+        # 2. Cross-Attn
+        if cross_attention_dim is not None or double_self_attention:
+            # We currently only use AdaLayerNormZero for self attention where there will only be one attention block.
+            # I.e. the number of returned modulation chunks from AdaLayerZero would not make sense if returned during
+            # the second cross attention block.
+            self.norm2 = (
+                AdaLayerNorm(dim, num_embeds_ada_norm)
+                if self.use_ada_layer_norm
+                else nn.LayerNorm(dim, elementwise_affine=norm_elementwise_affine)
+            )
+            self.attn2 = Attention(
+                query_dim=dim,
+                cross_attention_dim=cross_attention_dim
+                if not double_self_attention
+                else None,
+                heads=num_attention_heads,
+                dim_head=attention_head_dim,
+                dropout=dropout,
+                bias=attention_bias,
+                upcast_attention=upcast_attention,
+                # scale_qk=False, # uncomment this to not to use flash attention
+            )  # is self-attn if encoder_hidden_states is none
+        else:
+            self.norm2 = None
+            self.attn2 = None
+
+        # 3. Feed-forward
+        self.norm3 = nn.LayerNorm(dim, elementwise_affine=norm_elementwise_affine)
+        self.ff = FeedForward(
+            dim,
+            dropout=dropout,
+            activation_fn=activation_fn,
+            final_dropout=final_dropout,
+        )
+
+        # let chunk size default to None
+        self._chunk_size = None
+        self._chunk_dim = 0
+
+    def set_chunk_feed_forward(self, chunk_size: Optional[int], dim: int):
+        # Sets chunk feed-forward
+        self._chunk_size = chunk_size
+        self._chunk_dim = dim
+
+    def forward(
+        self,
+        hidden_states: torch.FloatTensor,
+        attention_mask: Optional[torch.FloatTensor] = None,
+        encoder_hidden_states: Optional[torch.FloatTensor] = None,
+        encoder_attention_mask: Optional[torch.FloatTensor] = None,
+        timestep: Optional[torch.LongTensor] = None,
+        cross_attention_kwargs: Dict[str, Any] = None,
+        class_labels: Optional[torch.LongTensor] = None,
+    ):
+        # Notice that normalization is always applied before the real computation in the following blocks.
+        # 1. Self-Attention
+        if self.use_ada_layer_norm:
+            norm_hidden_states = self.norm1(hidden_states, timestep)
+        elif self.use_ada_layer_norm_zero:
+            norm_hidden_states, gate_msa, shift_mlp, scale_mlp, gate_mlp = self.norm1(
+                hidden_states, timestep, class_labels, hidden_dtype=hidden_states.dtype
+            )
+        else:
+            norm_hidden_states = self.norm1(hidden_states)
+
+        cross_attention_kwargs = (
+            cross_attention_kwargs if cross_attention_kwargs is not None else {}
+        )
+
+        attn_output = self.attn1(
+            norm_hidden_states,
+            encoder_hidden_states=encoder_hidden_states
+            if self.only_cross_attention
+            else None,
+            attention_mask=encoder_attention_mask
+            if self.only_cross_attention
+            else attention_mask,
+            **cross_attention_kwargs,
+        )
+        if self.use_ada_layer_norm_zero:
+            attn_output = gate_msa.unsqueeze(1) * attn_output
+        hidden_states = attn_output + hidden_states
+
+        # 2. Cross-Attention
+        if self.attn2 is not None:
+            norm_hidden_states = (
+                self.norm2(hidden_states, timestep)
+                if self.use_ada_layer_norm
+                else self.norm2(hidden_states)
+            )
+
+            attn_output = self.attn2(
+                norm_hidden_states,
+                encoder_hidden_states=encoder_hidden_states,
+                attention_mask=encoder_attention_mask,
+                **cross_attention_kwargs,
+            )
+            hidden_states = attn_output + hidden_states
+
+        # 3. Feed-forward
+        norm_hidden_states = self.norm3(hidden_states)
+
+        if self.use_ada_layer_norm_zero:
+            norm_hidden_states = (
+                norm_hidden_states * (1 + scale_mlp[:, None]) + shift_mlp[:, None]
+            )
+
+        if self._chunk_size is not None:
+            # "feed_forward_chunk_size" can be used to save memory
+            if norm_hidden_states.shape[self._chunk_dim] % self._chunk_size != 0:
+                raise ValueError(
+                    f"`hidden_states` dimension to be chunked: {norm_hidden_states.shape[self._chunk_dim]} has to be divisible by chunk size: {self._chunk_size}. Make sure to set an appropriate `chunk_size` when calling `unet.enable_forward_chunking`."
+                )
+
+            num_chunks = norm_hidden_states.shape[self._chunk_dim] // self._chunk_size
+            ff_output = torch.cat(
+                [
+                    self.ff(hid_slice)
+                    for hid_slice in norm_hidden_states.chunk(
+                        num_chunks, dim=self._chunk_dim
+                    )
+                ],
+                dim=self._chunk_dim,
+            )
+        else:
+            ff_output = self.ff(norm_hidden_states)
+
+        if self.use_ada_layer_norm_zero:
+            ff_output = gate_mlp.unsqueeze(1) * ff_output
+
+        hidden_states = ff_output + hidden_states
+
+        return hidden_states
diff --git a/egs/ljspeech/TTS/matcha/models/matcha_tts.py b/egs/ljspeech/TTS/matcha/models/matcha_tts.py
new file mode 100644
index 0000000000..330d1dc472
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/models/matcha_tts.py
@@ -0,0 +1,295 @@
+import datetime as dt
+import math
+import random
+
+import matcha.monotonic_align as monotonic_align
+import torch
+from matcha.model import (
+    denormalize,
+    duration_loss,
+    fix_len_compatibility,
+    generate_path,
+    sequence_mask,
+)
+from matcha.models.components.flow_matching import CFM
+from matcha.models.components.text_encoder import TextEncoder
+
+
+class MatchaTTS(torch.nn.Module):  # 🍵
+    def __init__(
+        self,
+        n_vocab,
+        n_spks,
+        spk_emb_dim,
+        n_feats,
+        encoder,
+        decoder,
+        cfm,
+        data_statistics,
+        out_size,
+        optimizer=None,
+        scheduler=None,
+        prior_loss=True,
+        use_precomputed_durations=False,
+    ):
+        super().__init__()
+
+        #  self.save_hyperparameters(logger=False)
+
+        self.n_vocab = n_vocab
+        self.n_spks = n_spks
+        self.spk_emb_dim = spk_emb_dim
+        self.n_feats = n_feats
+        self.out_size = out_size
+        self.prior_loss = prior_loss
+        self.use_precomputed_durations = use_precomputed_durations
+
+        if n_spks > 1:
+            self.spk_emb = torch.nn.Embedding(n_spks, spk_emb_dim)
+
+        self.encoder = TextEncoder(
+            encoder.encoder_type,
+            encoder.encoder_params,
+            encoder.duration_predictor_params,
+            n_vocab,
+            n_spks,
+            spk_emb_dim,
+        )
+
+        self.decoder = CFM(
+            in_channels=2 * encoder.encoder_params.n_feats,
+            out_channel=encoder.encoder_params.n_feats,
+            cfm_params=cfm,
+            decoder_params=decoder,
+            n_spks=n_spks,
+            spk_emb_dim=spk_emb_dim,
+        )
+
+        if data_statistics is not None:
+            self.register_buffer("mel_mean", torch.tensor(data_statistics["mel_mean"]))
+            self.register_buffer("mel_std", torch.tensor(data_statistics["mel_std"]))
+        else:
+            self.register_buffer("mel_mean", torch.tensor(0.0))
+            self.register_buffer("mel_std", torch.tensor(1.0))
+
+    @torch.inference_mode()
+    def synthesise(
+        self, x, x_lengths, n_timesteps, temperature=1.0, spks=None, length_scale=1.0
+    ):
+        """
+        Generates mel-spectrogram from text. Returns:
+            1. encoder outputs
+            2. decoder outputs
+            3. generated alignment
+
+        Args:
+            x (torch.Tensor): batch of texts, converted to a tensor with phoneme embedding ids.
+                shape: (batch_size, max_text_length)
+            x_lengths (torch.Tensor): lengths of texts in batch.
+                shape: (batch_size,)
+            n_timesteps (int): number of steps to use for reverse diffusion in decoder.
+            temperature (float, optional): controls variance of terminal distribution.
+            spks (bool, optional): speaker ids.
+                shape: (batch_size,)
+            length_scale (float, optional): controls speech pace.
+                Increase value to slow down generated speech and vice versa.
+
+        Returns:
+            dict: {
+                "encoder_outputs": torch.Tensor, shape: (batch_size, n_feats, max_mel_length),
+                # Average mel spectrogram generated by the encoder
+                "decoder_outputs": torch.Tensor, shape: (batch_size, n_feats, max_mel_length),
+                # Refined mel spectrogram improved by the CFM
+                "attn": torch.Tensor, shape: (batch_size, max_text_length, max_mel_length),
+                # Alignment map between text and mel spectrogram
+                "mel": torch.Tensor, shape: (batch_size, n_feats, max_mel_length),
+                # Denormalized mel spectrogram
+                "mel_lengths": torch.Tensor, shape: (batch_size,),
+                # Lengths of mel spectrograms
+                "rtf": float,
+                # Real-time factor
+        """
+        # For RTF computation
+        t = dt.datetime.now()
+
+        if self.n_spks > 1:
+            # Get speaker embedding
+            spks = self.spk_emb(spks.long())
+
+        # Get encoder_outputs `mu_x` and log-scaled token durations `logw`
+        mu_x, logw, x_mask = self.encoder(x, x_lengths, spks)
+
+        w = torch.exp(logw) * x_mask
+        w_ceil = torch.ceil(w) * length_scale
+        y_lengths = torch.clamp_min(torch.sum(w_ceil, [1, 2]), 1).long()
+        y_max_length = y_lengths.max()
+        y_max_length_ = fix_len_compatibility(y_max_length)
+
+        # Using obtained durations `w` construct alignment map `attn`
+        y_mask = sequence_mask(y_lengths, y_max_length_).unsqueeze(1).to(x_mask.dtype)
+        attn_mask = x_mask.unsqueeze(-1) * y_mask.unsqueeze(2)
+        attn = generate_path(w_ceil.squeeze(1), attn_mask.squeeze(1)).unsqueeze(1)
+
+        # Align encoded text and get mu_y
+        mu_y = torch.matmul(attn.squeeze(1).transpose(1, 2), mu_x.transpose(1, 2))
+        mu_y = mu_y.transpose(1, 2)
+        encoder_outputs = mu_y[:, :, :y_max_length]
+
+        # Generate sample tracing the probability flow
+        decoder_outputs = self.decoder(mu_y, y_mask, n_timesteps, temperature, spks)
+        decoder_outputs = decoder_outputs[:, :, :y_max_length]
+
+        t = (dt.datetime.now() - t).total_seconds()
+        rtf = t * 22050 / (decoder_outputs.shape[-1] * 256)
+
+        return {
+            "encoder_outputs": encoder_outputs,
+            "decoder_outputs": decoder_outputs,
+            "attn": attn[:, :, :y_max_length],
+            "mel": denormalize(decoder_outputs, self.mel_mean, self.mel_std),
+            "mel_lengths": y_lengths,
+            "rtf": rtf,
+        }
+
+    def forward(
+        self,
+        x,
+        x_lengths,
+        y,
+        y_lengths,
+        spks=None,
+        out_size=None,
+        cond=None,
+        durations=None,
+    ):
+        """
+        Computes 3 losses:
+            1. duration loss: loss between predicted token durations and those extracted by Monotinic Alignment Search (MAS).
+            2. prior loss: loss between mel-spectrogram and encoder outputs.
+            3. flow matching loss: loss between mel-spectrogram and decoder outputs.
+
+        Args:
+            x (torch.Tensor): batch of texts, converted to a tensor with phoneme embedding ids.
+                shape: (batch_size, max_text_length)
+            x_lengths (torch.Tensor): lengths of texts in batch.
+                shape: (batch_size,)
+            y (torch.Tensor): batch of corresponding mel-spectrograms.
+                shape: (batch_size, n_feats, max_mel_length)
+            y_lengths (torch.Tensor): lengths of mel-spectrograms in batch.
+                shape: (batch_size,)
+            out_size (int, optional): length (in mel's sampling rate) of segment to cut, on which decoder will be trained.
+                Should be divisible by 2^{num of UNet downsamplings}. Needed to increase batch size.
+            spks (torch.Tensor, optional): speaker ids.
+                shape: (batch_size,)
+        """
+        if self.n_spks > 1:
+            # Get speaker embedding
+            spks = self.spk_emb(spks)
+
+        # Get encoder_outputs `mu_x` and log-scaled token durations `logw`
+        mu_x, logw, x_mask = self.encoder(x, x_lengths, spks)
+        y_max_length = y.shape[-1]
+
+        y_mask = sequence_mask(y_lengths, y_max_length).unsqueeze(1).to(x_mask)
+        attn_mask = x_mask.unsqueeze(-1) * y_mask.unsqueeze(2)
+
+        if self.use_precomputed_durations:
+            attn = generate_path(durations.squeeze(1), attn_mask.squeeze(1))
+        else:
+            # Use MAS to find most likely alignment `attn` between text and mel-spectrogram
+            with torch.no_grad():
+                const = -0.5 * math.log(2 * math.pi) * self.n_feats
+                factor = -0.5 * torch.ones(
+                    mu_x.shape, dtype=mu_x.dtype, device=mu_x.device
+                )
+                y_square = torch.matmul(factor.transpose(1, 2), y**2)
+                y_mu_double = torch.matmul(2.0 * (factor * mu_x).transpose(1, 2), y)
+                mu_square = torch.sum(factor * (mu_x**2), 1).unsqueeze(-1)
+                log_prior = y_square - y_mu_double + mu_square + const
+
+                attn = monotonic_align.maximum_path(log_prior, attn_mask.squeeze(1))
+                attn = attn.detach()  # b, t_text, T_mel
+
+        # Compute loss between predicted log-scaled durations and those obtained from MAS
+        # refered to as prior loss in the paper
+        logw_ = torch.log(1e-8 + torch.sum(attn.unsqueeze(1), -1)) * x_mask
+        dur_loss = duration_loss(logw, logw_, x_lengths)
+
+        # Cut a small segment of mel-spectrogram in order to increase batch size
+        #   - "Hack" taken from Grad-TTS, in case of Grad-TTS, we cannot train batch size 32 on a 24GB GPU without it
+        #   - Do not need this hack for Matcha-TTS, but it works with it as well
+        if not isinstance(out_size, type(None)):
+            max_offset = (y_lengths - out_size).clamp(0)
+            offset_ranges = list(
+                zip([0] * max_offset.shape[0], max_offset.cpu().numpy())
+            )
+            out_offset = torch.LongTensor(
+                [
+                    torch.tensor(random.choice(range(start, end)) if end > start else 0)
+                    for start, end in offset_ranges
+                ]
+            ).to(y_lengths)
+            attn_cut = torch.zeros(
+                attn.shape[0],
+                attn.shape[1],
+                out_size,
+                dtype=attn.dtype,
+                device=attn.device,
+            )
+            y_cut = torch.zeros(
+                y.shape[0], self.n_feats, out_size, dtype=y.dtype, device=y.device
+            )
+
+            y_cut_lengths = []
+            for i, (y_, out_offset_) in enumerate(zip(y, out_offset)):
+                y_cut_length = out_size + (y_lengths[i] - out_size).clamp(None, 0)
+                y_cut_lengths.append(y_cut_length)
+                cut_lower, cut_upper = out_offset_, out_offset_ + y_cut_length
+                y_cut[i, :, :y_cut_length] = y_[:, cut_lower:cut_upper]
+                attn_cut[i, :, :y_cut_length] = attn[i, :, cut_lower:cut_upper]
+
+            y_cut_lengths = torch.LongTensor(y_cut_lengths)
+            y_cut_mask = sequence_mask(y_cut_lengths).unsqueeze(1).to(y_mask)
+
+            attn = attn_cut
+            y = y_cut
+            y_mask = y_cut_mask
+
+        # Align encoded text with mel-spectrogram and get mu_y segment
+        mu_y = torch.matmul(attn.squeeze(1).transpose(1, 2), mu_x.transpose(1, 2))
+        mu_y = mu_y.transpose(1, 2)
+
+        # Compute loss of the decoder
+        diff_loss, _ = self.decoder.compute_loss(
+            x1=y, mask=y_mask, mu=mu_y, spks=spks, cond=cond
+        )
+
+        if self.prior_loss:
+            prior_loss = torch.sum(
+                0.5 * ((y - mu_y) ** 2 + math.log(2 * math.pi)) * y_mask
+            )
+            prior_loss = prior_loss / (torch.sum(y_mask) * self.n_feats)
+        else:
+            prior_loss = 0
+
+        return dur_loss, prior_loss, diff_loss, attn
+
+    def get_losses(self, batch):
+        x, x_lengths = batch["x"], batch["x_lengths"]
+        y, y_lengths = batch["y"], batch["y_lengths"]
+        spks = batch["spks"]
+
+        dur_loss, prior_loss, diff_loss, *_ = self(
+            x=x,
+            x_lengths=x_lengths,
+            y=y,
+            y_lengths=y_lengths,
+            spks=spks,
+            out_size=self.out_size,
+            durations=batch["durations"],
+        )
+        return {
+            "dur_loss": dur_loss,
+            "prior_loss": prior_loss,
+            "diff_loss": diff_loss,
+        }
diff --git a/egs/ljspeech/TTS/matcha/monotonic_align/.gitignore b/egs/ljspeech/TTS/matcha/monotonic_align/.gitignore
new file mode 100644
index 0000000000..28bdad6b84
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/monotonic_align/.gitignore
@@ -0,0 +1,3 @@
+build
+core.c
+*.so
diff --git a/egs/ljspeech/TTS/matcha/monotonic_align/__init__.py b/egs/ljspeech/TTS/matcha/monotonic_align/__init__.py
new file mode 100644
index 0000000000..5b26fe4743
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/monotonic_align/__init__.py
@@ -0,0 +1,23 @@
+# Copied from
+# https://github.com/shivammehta25/Matcha-TTS/blob/main/matcha/utils/monotonic_align/__init__.py
+import numpy as np
+import torch
+from matcha.monotonic_align.core import maximum_path_c
+
+
+def maximum_path(value, mask):
+    """Cython optimised version.
+    value: [b, t_x, t_y]
+    mask: [b, t_x, t_y]
+    """
+    value = value * mask
+    device = value.device
+    dtype = value.dtype
+    value = value.data.cpu().numpy().astype(np.float32)
+    path = np.zeros_like(value).astype(np.int32)
+    mask = mask.data.cpu().numpy()
+
+    t_x_max = mask.sum(1)[:, 0].astype(np.int32)
+    t_y_max = mask.sum(2)[:, 0].astype(np.int32)
+    maximum_path_c(path, value, t_x_max, t_y_max)
+    return torch.from_numpy(path).to(device=device, dtype=dtype)
diff --git a/egs/ljspeech/TTS/matcha/monotonic_align/core.pyx b/egs/ljspeech/TTS/matcha/monotonic_align/core.pyx
new file mode 100644
index 0000000000..eabc7f2736
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/monotonic_align/core.pyx
@@ -0,0 +1,49 @@
+# Copied from
+# https://github.com/shivammehta25/Matcha-TTS/blob/main/matcha/utils/monotonic_align/core.pyx
+import numpy as np
+
+cimport cython
+cimport numpy as np
+
+from cython.parallel import prange
+
+
+@cython.boundscheck(False)
+@cython.wraparound(False)
+cdef void maximum_path_each(int[:,::1] path, float[:,::1] value, int t_x, int t_y, float max_neg_val) nogil:
+  cdef int x
+  cdef int y
+  cdef float v_prev
+  cdef float v_cur
+  cdef float tmp
+  cdef int index = t_x - 1
+
+  for y in range(t_y):
+    for x in range(max(0, t_x + y - t_y), min(t_x, y + 1)):
+      if x == y:
+        v_cur = max_neg_val
+      else:
+        v_cur = value[x, y-1]
+      if x == 0:
+        if y == 0:
+          v_prev = 0.
+        else:
+          v_prev = max_neg_val
+      else:
+        v_prev = value[x-1, y-1]
+      value[x, y] = max(v_cur, v_prev) + value[x, y]
+
+  for y in range(t_y - 1, -1, -1):
+    path[index, y] = 1
+    if index != 0 and (index == y or value[index, y-1] < value[index-1, y-1]):
+      index = index - 1
+
+
+@cython.boundscheck(False)
+@cython.wraparound(False)
+cpdef void maximum_path_c(int[:,:,::1] paths, float[:,:,::1] values, int[::1] t_xs, int[::1] t_ys, float max_neg_val=-1e9) nogil:
+  cdef int b = values.shape[0]
+
+  cdef int i
+  for i in prange(b, nogil=True):
+    maximum_path_each(paths[i], values[i], t_xs[i], t_ys[i], max_neg_val)
diff --git a/egs/ljspeech/TTS/matcha/monotonic_align/setup.py b/egs/ljspeech/TTS/matcha/monotonic_align/setup.py
new file mode 100644
index 0000000000..df26c633e0
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/monotonic_align/setup.py
@@ -0,0 +1,12 @@
+# Copied from
+# https://github.com/shivammehta25/Matcha-TTS/blob/main/matcha/utils/monotonic_align/setup.py
+from distutils.core import setup
+
+import numpy
+from Cython.Build import cythonize
+
+setup(
+    name="monotonic_align",
+    ext_modules=cythonize("core.pyx"),
+    include_dirs=[numpy.get_include()],
+)
diff --git a/egs/ljspeech/TTS/matcha/onnx_pretrained.py b/egs/ljspeech/TTS/matcha/onnx_pretrained.py
new file mode 100755
index 0000000000..be34343d3b
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/onnx_pretrained.py
@@ -0,0 +1,204 @@
+#!/usr/bin/env python3
+# Copyright         2024  Xiaomi Corp.        (authors: Fangjun Kuang)
+
+import argparse
+import datetime as dt
+import logging
+
+import onnxruntime as ort
+import soundfile as sf
+import torch
+from inference import load_vocoder
+from tokenizer import Tokenizer
+
+
+def get_parser():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter
+    )
+
+    parser.add_argument(
+        "--acoustic-model",
+        type=str,
+        required=True,
+        help="Path to the acoustic model",
+    )
+
+    parser.add_argument(
+        "--tokens",
+        type=str,
+        required=True,
+        help="Path to the tokens.txt",
+    )
+
+    parser.add_argument(
+        "--vocoder",
+        type=str,
+        required=True,
+        help="Path to the vocoder",
+    )
+
+    parser.add_argument(
+        "--input-text",
+        type=str,
+        required=True,
+        help="The text to generate speech for",
+    )
+
+    parser.add_argument(
+        "--output-wav",
+        type=str,
+        required=True,
+        help="The filename of the wave to save the generated speech",
+    )
+
+    return parser
+
+
+class OnnxHifiGANModel:
+    def __init__(
+        self,
+        filename: str,
+    ):
+        session_opts = ort.SessionOptions()
+        session_opts.inter_op_num_threads = 1
+        session_opts.intra_op_num_threads = 1
+
+        self.session_opts = session_opts
+        self.model = ort.InferenceSession(
+            filename,
+            sess_options=self.session_opts,
+            providers=["CPUExecutionProvider"],
+        )
+
+        for i in self.model.get_inputs():
+            print(i)
+
+        print("-----")
+
+        for i in self.model.get_outputs():
+            print(i)
+
+    def __call__(self, x: torch.tensor):
+        assert x.ndim == 3, x.shape
+        assert x.shape[0] == 1, x.shape
+
+        audio = self.model.run(
+            [self.model.get_outputs()[0].name],
+            {
+                self.model.get_inputs()[0].name: x.numpy(),
+            },
+        )[0]
+
+        return torch.from_numpy(audio)
+
+
+class OnnxModel:
+    def __init__(
+        self,
+        filename: str,
+    ):
+        session_opts = ort.SessionOptions()
+        session_opts.inter_op_num_threads = 1
+        session_opts.intra_op_num_threads = 2
+
+        self.session_opts = session_opts
+        self.tokenizer = Tokenizer("./data/tokens.txt")
+        self.model = ort.InferenceSession(
+            filename,
+            sess_options=self.session_opts,
+            providers=["CPUExecutionProvider"],
+        )
+
+        for i in self.model.get_inputs():
+            print(i)
+
+        print("-----")
+
+        for i in self.model.get_outputs():
+            print(i)
+
+    def __call__(self, x: torch.tensor):
+        assert x.ndim == 2, x.shape
+        assert x.shape[0] == 1, x.shape
+
+        x_lengths = torch.tensor([x.shape[1]], dtype=torch.int64)
+        print("x_lengths", x_lengths)
+        print("x", x.shape)
+
+        temperature = torch.tensor([1.0], dtype=torch.float32)
+        length_scale = torch.tensor([1.0], dtype=torch.float32)
+
+        mel = self.model.run(
+            [self.model.get_outputs()[0].name],
+            {
+                self.model.get_inputs()[0].name: x.numpy(),
+                self.model.get_inputs()[1].name: x_lengths.numpy(),
+                self.model.get_inputs()[2].name: temperature.numpy(),
+                self.model.get_inputs()[3].name: length_scale.numpy(),
+            },
+        )[0]
+
+        return torch.from_numpy(mel)
+
+
+@torch.no_grad()
+def main():
+    params = get_parser().parse_args()
+    logging.info(vars(params))
+
+    model = OnnxModel(params.acoustic_model)
+    vocoder = OnnxHifiGANModel(params.vocoder)
+    text = params.input_text
+    x = model.tokenizer.texts_to_token_ids([text], add_sos=True, add_eos=True)
+    x = torch.tensor(x, dtype=torch.int64)
+
+    start_t = dt.datetime.now()
+    mel = model(x)
+    end_t = dt.datetime.now()
+
+    start_t2 = dt.datetime.now()
+    audio = vocoder(mel)
+    end_t2 = dt.datetime.now()
+
+    print("audio", audio.shape)  # (1, 1, num_samples)
+    audio = audio.squeeze()
+
+    t = (end_t - start_t).total_seconds()
+    t2 = (end_t2 - start_t2).total_seconds()
+    rtf_am = t * 22050 / audio.shape[-1]
+    rtf_vocoder = t2 * 22050 / audio.shape[-1]
+    print("RTF for acoustic model ", rtf_am)
+    print("RTF for vocoder", rtf_vocoder)
+
+    # skip denoiser
+    sf.write(params.output_wav, audio, 22050, "PCM_16")
+    logging.info(f"Saved to {params.output_wav}")
+
+
+if __name__ == "__main__":
+    torch.set_num_threads(1)
+    torch.set_num_interop_threads(1)
+
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+    main()
+
+"""
+
+|HifiGAN   |RTF  |#Parameters (M)|
+|----------|-----|---------------|
+|v1        |0.818|  13.926       |
+|v2        |0.101|   0.925       |
+|v3        |0.118|   1.462       |
+
+|Num steps|Acoustic Model RTF|
+|---------|------------------|
+| 2       |    0.039         |
+| 3       |    0.047         |
+| 4       |    0.071         |
+| 5       |    0.076         |
+| 6       |    0.103         |
+
+"""
diff --git a/egs/ljspeech/TTS/matcha/requirements.txt b/egs/ljspeech/TTS/matcha/requirements.txt
new file mode 100644
index 0000000000..5aadc89844
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/requirements.txt
@@ -0,0 +1,3 @@
+conformer==0.3.2
+diffusers # developed using version ==0.25.0
+librosa
diff --git a/egs/ljspeech/TTS/matcha/tokenizer.py b/egs/ljspeech/TTS/matcha/tokenizer.py
new file mode 120000
index 0000000000..44a19b0f4a
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/tokenizer.py
@@ -0,0 +1 @@
+../vits/tokenizer.py
\ No newline at end of file
diff --git a/egs/ljspeech/TTS/matcha/train.py b/egs/ljspeech/TTS/matcha/train.py
new file mode 100755
index 0000000000..5e713fdfdb
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/train.py
@@ -0,0 +1,723 @@
+#!/usr/bin/env python3
+# Copyright         2024  Xiaomi Corp.        (authors: Fangjun Kuang)
+
+
+import argparse
+import json
+import logging
+from pathlib import Path
+from shutil import copyfile
+from typing import Any, Dict, Optional, Union
+
+import k2
+import torch
+import torch.multiprocessing as mp
+import torch.nn as nn
+from lhotse.utils import fix_random_seed
+from matcha.model import fix_len_compatibility
+from matcha.models.matcha_tts import MatchaTTS
+from matcha.tokenizer import Tokenizer
+from torch.cuda.amp import GradScaler, autocast
+from torch.nn.parallel import DistributedDataParallel as DDP
+from torch.optim import Optimizer
+from torch.utils.tensorboard import SummaryWriter
+from tts_datamodule import LJSpeechTtsDataModule
+from utils import MetricsTracker
+
+from icefall.checkpoint import load_checkpoint, save_checkpoint
+from icefall.dist import cleanup_dist, setup_dist
+from icefall.env import get_env_info
+from icefall.utils import AttributeDict, setup_logger, str2bool
+
+
+def get_parser():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter
+    )
+
+    parser.add_argument(
+        "--world-size",
+        type=int,
+        default=1,
+        help="Number of GPUs for DDP training.",
+    )
+
+    parser.add_argument(
+        "--master-port",
+        type=int,
+        default=12335,
+        help="Master port to use for DDP training.",
+    )
+
+    parser.add_argument(
+        "--tensorboard",
+        type=str2bool,
+        default=True,
+        help="Should various information be logged in tensorboard.",
+    )
+
+    parser.add_argument(
+        "--num-epochs",
+        type=int,
+        default=1000,
+        help="Number of epochs to train.",
+    )
+
+    parser.add_argument(
+        "--start-epoch",
+        type=int,
+        default=1,
+        help="""Resume training from this epoch. It should be positive.
+        If larger than 1, it will load checkpoint from
+        exp-dir/epoch-{start_epoch-1}.pt
+        """,
+    )
+
+    parser.add_argument(
+        "--exp-dir",
+        type=Path,
+        default="matcha/exp",
+        help="""The experiment dir.
+        It specifies the directory where all training related
+        files, e.g., checkpoints, log, etc, are saved
+        """,
+    )
+
+    parser.add_argument(
+        "--tokens",
+        type=str,
+        default="data/tokens.txt",
+        help="""Path to vocabulary.""",
+    )
+
+    parser.add_argument(
+        "--cmvn",
+        type=str,
+        default="data/fbank/cmvn.json",
+        help="""Path to vocabulary.""",
+    )
+
+    parser.add_argument(
+        "--seed",
+        type=int,
+        default=42,
+        help="The seed for random generators intended for reproducibility",
+    )
+
+    parser.add_argument(
+        "--save-every-n",
+        type=int,
+        default=10,
+        help="""Save checkpoint after processing this number of epochs"
+        periodically. We save checkpoint to exp-dir/ whenever
+        params.cur_epoch % save_every_n == 0. The checkpoint filename
+        has the form: f'exp-dir/epoch-{params.cur_epoch}.pt'.
+        Since it will take around 1000 epochs, we suggest using a large
+        save_every_n to save disk space.
+        """,
+    )
+
+    parser.add_argument(
+        "--use-fp16",
+        type=str2bool,
+        default=False,
+        help="Whether to use half precision training.",
+    )
+
+    return parser
+
+
+def get_data_statistics():
+    return AttributeDict(
+        {
+            "mel_mean": 0,
+            "mel_std": 1,
+        }
+    )
+
+
+def _get_data_params() -> AttributeDict:
+    params = AttributeDict(
+        {
+            "name": "ljspeech",
+            "train_filelist_path": "./filelists/ljs_audio_text_train_filelist.txt",
+            "valid_filelist_path": "./filelists/ljs_audio_text_val_filelist.txt",
+            #  "batch_size": 64,
+            #  "num_workers": 1,
+            #  "pin_memory": False,
+            "cleaners": ["english_cleaners2"],
+            "add_blank": True,
+            "n_spks": 1,
+            "n_fft": 1024,
+            "n_feats": 80,
+            "sample_rate": 22050,
+            "hop_length": 256,
+            "win_length": 1024,
+            "f_min": 0,
+            "f_max": 8000,
+            "seed": 1234,
+            "load_durations": False,
+            "data_statistics": get_data_statistics(),
+        }
+    )
+    return params
+
+
+def _get_model_params() -> AttributeDict:
+    n_feats = 80
+    filter_channels_dp = 256
+    encoder_params_p_dropout = 0.1
+    params = AttributeDict(
+        {
+            "n_spks": 1,  # for ljspeech.
+            "spk_emb_dim": 64,
+            "n_feats": n_feats,
+            "out_size": None,  # or use 172
+            "prior_loss": True,
+            "use_precomputed_durations": False,
+            "data_statistics": get_data_statistics(),
+            "encoder": AttributeDict(
+                {
+                    "encoder_type": "RoPE Encoder",  # not used
+                    "encoder_params": AttributeDict(
+                        {
+                            "n_feats": n_feats,
+                            "n_channels": 192,
+                            "filter_channels": 768,
+                            "filter_channels_dp": filter_channels_dp,
+                            "n_heads": 2,
+                            "n_layers": 6,
+                            "kernel_size": 3,
+                            "p_dropout": encoder_params_p_dropout,
+                            "spk_emb_dim": 64,
+                            "n_spks": 1,
+                            "prenet": True,
+                        }
+                    ),
+                    "duration_predictor_params": AttributeDict(
+                        {
+                            "filter_channels_dp": filter_channels_dp,
+                            "kernel_size": 3,
+                            "p_dropout": encoder_params_p_dropout,
+                        }
+                    ),
+                }
+            ),
+            "decoder": AttributeDict(
+                {
+                    "channels": [256, 256],
+                    "dropout": 0.05,
+                    "attention_head_dim": 64,
+                    "n_blocks": 1,
+                    "num_mid_blocks": 2,
+                    "num_heads": 2,
+                    "act_fn": "snakebeta",
+                }
+            ),
+            "cfm": AttributeDict(
+                {
+                    "name": "CFM",
+                    "solver": "euler",
+                    "sigma_min": 1e-4,
+                }
+            ),
+            "optimizer": AttributeDict(
+                {
+                    "lr": 1e-4,
+                    "weight_decay": 0.0,
+                }
+            ),
+        }
+    )
+
+    return params
+
+
+def get_params():
+    params = AttributeDict(
+        {
+            "model_args": _get_model_params(),
+            "data_args": _get_data_params(),
+            "best_train_loss": float("inf"),
+            "best_valid_loss": float("inf"),
+            "best_train_epoch": -1,
+            "best_valid_epoch": -1,
+            "batch_idx_train": -1,  # 0
+            "log_interval": 10,
+            "valid_interval": 1500,
+            "env_info": get_env_info(),
+        }
+    )
+    return params
+
+
+def get_model(params):
+    m = MatchaTTS(**params.model_args)
+    return m
+
+
+def load_checkpoint_if_available(
+    params: AttributeDict, model: nn.Module
+) -> Optional[Dict[str, Any]]:
+    """Load checkpoint from file.
+
+    If params.start_epoch is larger than 1, it will load the checkpoint from
+    `params.start_epoch - 1`.
+
+    Apart from loading state dict for `model` and `optimizer` it also updates
+    `best_train_epoch`, `best_train_loss`, `best_valid_epoch`,
+    and `best_valid_loss` in `params`.
+
+    Args:
+      params:
+        The return value of :func:`get_params`.
+      model:
+        The training model.
+    Returns:
+      Return a dict containing previously saved training info.
+    """
+    if params.start_epoch > 1:
+        filename = params.exp_dir / f"epoch-{params.start_epoch-1}.pt"
+    else:
+        return None
+
+    assert filename.is_file(), f"{filename} does not exist!"
+
+    saved_params = load_checkpoint(filename, model=model)
+
+    keys = [
+        "best_train_epoch",
+        "best_valid_epoch",
+        "batch_idx_train",
+        "best_train_loss",
+        "best_valid_loss",
+    ]
+    for k in keys:
+        params[k] = saved_params[k]
+
+    return saved_params
+
+
+def prepare_input(batch: dict, tokenizer: Tokenizer, device: torch.device, params):
+    """Parse batch data"""
+    mel_mean = params.data_args.data_statistics.mel_mean
+    mel_std_inv = 1 / params.data_args.data_statistics.mel_std
+    for i in range(batch["features"].shape[0]):
+        n = batch["features_lens"][i]
+        batch["features"][i : i + 1, :n, :] = (
+            batch["features"][i : i + 1, :n, :] - mel_mean
+        ) * mel_std_inv
+        batch["features"][i : i + 1, n:, :] = 0
+
+    audio = batch["audio"].to(device)
+    features = batch["features"].to(device)
+    audio_lens = batch["audio_lens"].to(device)
+    features_lens = batch["features_lens"].to(device)
+    tokens = batch["tokens"]
+
+    tokens = tokenizer.tokens_to_token_ids(
+        tokens, intersperse_blank=True, add_sos=True, add_eos=True
+    )
+    tokens = k2.RaggedTensor(tokens)
+    row_splits = tokens.shape.row_splits(1)
+    tokens_lens = row_splits[1:] - row_splits[:-1]
+    tokens = tokens.to(device)
+    tokens_lens = tokens_lens.to(device)
+    # a tensor of shape (B, T)
+    tokens = tokens.pad(mode="constant", padding_value=tokenizer.pad_id)
+
+    max_feature_length = fix_len_compatibility(features.shape[1])
+    if max_feature_length > features.shape[1]:
+        pad = max_feature_length - features.shape[1]
+        features = torch.nn.functional.pad(features, (0, 0, 0, pad))
+
+        #  features_lens[features_lens.argmax()] += pad
+
+    return audio, audio_lens, features, features_lens.long(), tokens, tokens_lens.long()
+
+
+def compute_validation_loss(
+    params: AttributeDict,
+    model: Union[nn.Module, DDP],
+    tokenizer: Tokenizer,
+    valid_dl: torch.utils.data.DataLoader,
+    world_size: int = 1,
+    rank: int = 0,
+) -> MetricsTracker:
+    """Run the validation process."""
+    model.eval()
+    device = model.device if isinstance(model, DDP) else next(model.parameters()).device
+    get_losses = model.module.get_losses if isinstance(model, DDP) else model.get_losses
+
+    # used to summary the stats over iterations
+    tot_loss = MetricsTracker()
+
+    with torch.no_grad():
+        for batch_idx, batch in enumerate(valid_dl):
+            (
+                audio,
+                audio_lens,
+                features,
+                features_lens,
+                tokens,
+                tokens_lens,
+            ) = prepare_input(batch, tokenizer, device, params)
+
+            losses = get_losses(
+                {
+                    "x": tokens,
+                    "x_lengths": tokens_lens,
+                    "y": features.permute(0, 2, 1),
+                    "y_lengths": features_lens,
+                    "spks": None,  # should change it for multi-speakers
+                    "durations": None,
+                }
+            )
+
+            batch_size = len(batch["tokens"])
+
+            loss_info = MetricsTracker()
+            loss_info["samples"] = batch_size
+
+            s = 0
+
+            for key, value in losses.items():
+                v = value.detach().item()
+                loss_info[key] = v * batch_size
+                s += v * batch_size
+
+            loss_info["tot_loss"] = s
+
+            # summary stats
+            tot_loss = tot_loss + loss_info
+
+    if world_size > 1:
+        tot_loss.reduce(device)
+
+    loss_value = tot_loss["tot_loss"] / tot_loss["samples"]
+    if loss_value < params.best_valid_loss:
+        params.best_valid_epoch = params.cur_epoch
+        params.best_valid_loss = loss_value
+
+    return tot_loss
+
+
+def train_one_epoch(
+    params: AttributeDict,
+    model: Union[nn.Module, DDP],
+    tokenizer: Tokenizer,
+    optimizer: Optimizer,
+    train_dl: torch.utils.data.DataLoader,
+    valid_dl: torch.utils.data.DataLoader,
+    scaler: GradScaler,
+    tb_writer: Optional[SummaryWriter] = None,
+    world_size: int = 1,
+    rank: int = 0,
+) -> None:
+    """Train the model for one epoch.
+
+    The training loss from the mean of all frames is saved in
+    `params.train_loss`. It runs the validation process every
+    `params.valid_interval` batches.
+
+    Args:
+      params:
+        It is returned by :func:`get_params`.
+      model:
+        The model for training.
+      optimizer:
+        The optimizer.
+      train_dl:
+        Dataloader for the training dataset.
+      valid_dl:
+        Dataloader for the validation dataset.
+      scaler:
+        The scaler used for mix precision training.
+      tb_writer:
+        Writer to write log messages to tensorboard.
+    """
+    model.train()
+    device = model.device if isinstance(model, DDP) else next(model.parameters()).device
+    get_losses = model.module.get_losses if isinstance(model, DDP) else model.get_losses
+
+    # used to track the stats over iterations in one epoch
+    tot_loss = MetricsTracker()
+
+    saved_bad_model = False
+
+    # used to track the stats over iterations in one epoch
+    tot_loss = MetricsTracker()
+
+    saved_bad_model = False
+
+    def save_bad_model(suffix: str = ""):
+        save_checkpoint(
+            filename=params.exp_dir / f"bad-model{suffix}-{rank}.pt",
+            model=model,
+            params=params,
+            optimizer=optimizer,
+            scaler=scaler,
+            rank=0,
+        )
+
+    for batch_idx, batch in enumerate(train_dl):
+        params.batch_idx_train += 1
+        # audio: (N, T), float32
+        # features: (N, T, C), float32
+        # audio_lens, (N,), int32
+        # features_lens, (N,), int32
+        # tokens: List[List[str]], len(tokens) == N
+
+        batch_size = len(batch["tokens"])
+
+        (
+            audio,
+            audio_lens,
+            features,
+            features_lens,
+            tokens,
+            tokens_lens,
+        ) = prepare_input(batch, tokenizer, device, params)
+        try:
+            with autocast(enabled=params.use_fp16):
+                losses = get_losses(
+                    {
+                        "x": tokens,
+                        "x_lengths": tokens_lens,
+                        "y": features.permute(0, 2, 1),
+                        "y_lengths": features_lens,
+                        "spks": None,  # should change it for multi-speakers
+                        "durations": None,
+                    }
+                )
+
+                loss = sum(losses.values())
+
+                optimizer.zero_grad()
+                scaler.scale(loss).backward()
+                scaler.step(optimizer)
+
+                loss_info = MetricsTracker()
+                loss_info["samples"] = batch_size
+
+                s = 0
+
+                for key, value in losses.items():
+                    v = value.detach().item()
+                    loss_info[key] = v * batch_size
+                    s += v * batch_size
+
+                loss_info["tot_loss"] = s
+
+                tot_loss = tot_loss + loss_info
+        except:  # noqa
+            save_bad_model()
+            raise
+
+        if params.batch_idx_train % 100 == 0 and params.use_fp16:
+            # If the grad scale was less than 1, try increasing it.
+            # The _growth_interval of the grad scaler is configurable,
+            # but we can't configure it to have different
+            # behavior depending on the current grad scale.
+            cur_grad_scale = scaler._scale.item()
+
+            if cur_grad_scale < 8.0 or (
+                cur_grad_scale < 32.0 and params.batch_idx_train % 400 == 0
+            ):
+                scaler.update(cur_grad_scale * 2.0)
+            if cur_grad_scale < 0.01:
+                if not saved_bad_model:
+                    save_bad_model(suffix="-first-warning")
+                    saved_bad_model = True
+                logging.warning(f"Grad scale is small: {cur_grad_scale}")
+            if cur_grad_scale < 1.0e-05:
+                save_bad_model()
+                raise RuntimeError(
+                    f"grad_scale is too small, exiting: {cur_grad_scale}"
+                )
+
+        if params.batch_idx_train % params.log_interval == 0:
+            cur_grad_scale = scaler._scale.item() if params.use_fp16 else 1.0
+
+            logging.info(
+                f"Epoch {params.cur_epoch}, batch {batch_idx}, "
+                f"global_batch_idx: {params.batch_idx_train}, "
+                f"batch size: {batch_size}, "
+                f"loss[{loss_info}], tot_loss[{tot_loss}], "
+                + (f"grad_scale: {scaler._scale.item()}" if params.use_fp16 else "")
+            )
+
+            if tb_writer is not None:
+                loss_info.write_summary(
+                    tb_writer, "train/current_", params.batch_idx_train
+                )
+                tot_loss.write_summary(tb_writer, "train/tot_", params.batch_idx_train)
+                if params.use_fp16:
+                    tb_writer.add_scalar(
+                        "train/grad_scale", cur_grad_scale, params.batch_idx_train
+                    )
+
+        if params.batch_idx_train % params.valid_interval == 1:
+            logging.info("Computing validation loss")
+            valid_info = compute_validation_loss(
+                params=params,
+                model=model,
+                tokenizer=tokenizer,
+                valid_dl=valid_dl,
+                world_size=world_size,
+                rank=rank,
+            )
+            model.train()
+            logging.info(f"Epoch {params.cur_epoch}, validation: {valid_info}")
+            logging.info(
+                "Maximum memory allocated so far is "
+                f"{torch.cuda.max_memory_allocated()//1000000}MB"
+            )
+            if tb_writer is not None:
+                valid_info.write_summary(
+                    tb_writer, "train/valid_", params.batch_idx_train
+                )
+
+    loss_value = tot_loss["tot_loss"] / tot_loss["samples"]
+    params.train_loss = loss_value
+    if params.train_loss < params.best_train_loss:
+        params.best_train_epoch = params.cur_epoch
+        params.best_train_loss = params.train_loss
+
+
+def run(rank, world_size, args):
+    params = get_params()
+    params.update(vars(args))
+
+    fix_random_seed(params.seed)
+    if world_size > 1:
+        setup_dist(rank, world_size, params.master_port)
+
+    setup_logger(f"{params.exp_dir}/log/log-train")
+    logging.info("Training started")
+
+    if args.tensorboard and rank == 0:
+        tb_writer = SummaryWriter(log_dir=f"{params.exp_dir}/tensorboard")
+    else:
+        tb_writer = None
+
+    device = torch.device("cpu")
+    if torch.cuda.is_available():
+        device = torch.device("cuda", rank)
+    logging.info(f"Device: {device}")
+
+    tokenizer = Tokenizer(params.tokens)
+    params.pad_id = tokenizer.pad_id
+    params.vocab_size = tokenizer.vocab_size
+    params.model_args.n_vocab = params.vocab_size
+
+    with open(params.cmvn) as f:
+        stats = json.load(f)
+        params.data_args.data_statistics.mel_mean = stats["fbank_mean"]
+        params.data_args.data_statistics.mel_std = stats["fbank_std"]
+
+        params.model_args.data_statistics.mel_mean = stats["fbank_mean"]
+        params.model_args.data_statistics.mel_std = stats["fbank_std"]
+
+    logging.info(params)
+    print(params)
+
+    logging.info("About to create model")
+    model = get_model(params)
+
+    num_param = sum([p.numel() for p in model.parameters()])
+    logging.info(f"Number of parameters: {num_param}")
+
+    assert params.start_epoch > 0, params.start_epoch
+    checkpoints = load_checkpoint_if_available(params=params, model=model)
+
+    model.to(device)
+
+    if world_size > 1:
+        logging.info("Using DDP")
+        model = DDP(model, device_ids=[rank], find_unused_parameters=True)
+
+    optimizer = torch.optim.Adam(model.parameters(), **params.model_args.optimizer)
+
+    logging.info("About to create datamodule")
+
+    ljspeech = LJSpeechTtsDataModule(args)
+
+    train_cuts = ljspeech.train_cuts()
+    train_dl = ljspeech.train_dataloaders(train_cuts)
+
+    valid_cuts = ljspeech.valid_cuts()
+    valid_dl = ljspeech.valid_dataloaders(valid_cuts)
+
+    scaler = GradScaler(enabled=params.use_fp16, init_scale=1.0)
+    if checkpoints and "grad_scaler" in checkpoints:
+        logging.info("Loading grad scaler state dict")
+        scaler.load_state_dict(checkpoints["grad_scaler"])
+
+    for epoch in range(params.start_epoch, params.num_epochs + 1):
+        logging.info(f"Start epoch {epoch}")
+        fix_random_seed(params.seed + epoch - 1)
+        if "sampler" in train_dl:
+            train_dl.sampler.set_epoch(epoch - 1)
+
+        params.cur_epoch = epoch
+
+        if tb_writer is not None:
+            tb_writer.add_scalar("train/epoch", epoch, params.batch_idx_train)
+
+        train_one_epoch(
+            params=params,
+            model=model,
+            tokenizer=tokenizer,
+            optimizer=optimizer,
+            train_dl=train_dl,
+            valid_dl=valid_dl,
+            scaler=scaler,
+            tb_writer=tb_writer,
+            world_size=world_size,
+            rank=rank,
+        )
+
+        if epoch % params.save_every_n == 0 or epoch == params.num_epochs:
+            filename = params.exp_dir / f"epoch-{params.cur_epoch}.pt"
+            save_checkpoint(
+                filename=filename,
+                params=params,
+                model=model,
+                optimizer=optimizer,
+                scaler=scaler,
+                rank=rank,
+            )
+            if rank == 0:
+                if params.best_train_epoch == params.cur_epoch:
+                    best_train_filename = params.exp_dir / "best-train-loss.pt"
+                    copyfile(src=filename, dst=best_train_filename)
+
+                if params.best_valid_epoch == params.cur_epoch:
+                    best_valid_filename = params.exp_dir / "best-valid-loss.pt"
+                    copyfile(src=filename, dst=best_valid_filename)
+
+    logging.info("Done!")
+
+    if world_size > 1:
+        torch.distributed.barrier()
+        cleanup_dist()
+
+
+def main():
+    parser = get_parser()
+    LJSpeechTtsDataModule.add_arguments(parser)
+    args = parser.parse_args()
+
+    world_size = args.world_size
+    assert world_size >= 1
+    if world_size > 1:
+        mp.spawn(run, args=(world_size, args), nprocs=world_size, join=True)
+    else:
+        run(rank=0, world_size=1, args=args)
+
+
+if __name__ == "__main__":
+    torch.set_num_threads(1)
+    torch.set_num_interop_threads(1)
+    main()
diff --git a/egs/ljspeech/TTS/matcha/tts_datamodule.py b/egs/ljspeech/TTS/matcha/tts_datamodule.py
new file mode 100644
index 0000000000..8e37fc0308
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/tts_datamodule.py
@@ -0,0 +1,341 @@
+# Copyright      2021  Piotr Żelasko
+# Copyright      2022-2023  Xiaomi Corporation     (Authors: Mingshuang Luo,
+#                                                            Zengwei Yao)
+#
+# See ../../../../LICENSE for clarification regarding multiple authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import argparse
+import logging
+from functools import lru_cache
+from pathlib import Path
+from typing import Any, Dict, Optional
+
+import torch
+from compute_fbank_ljspeech import MyFbank, MyFbankConfig
+from lhotse import CutSet, load_manifest_lazy
+from lhotse.dataset import (  # noqa F401 for PrecomputedFeatures
+    CutConcatenate,
+    CutMix,
+    DynamicBucketingSampler,
+    PrecomputedFeatures,
+    SimpleCutSampler,
+    SpecAugment,
+    SpeechSynthesisDataset,
+)
+from lhotse.dataset.input_strategies import (  # noqa F401 For AudioSamples
+    AudioSamples,
+    OnTheFlyFeatures,
+)
+from lhotse.utils import fix_random_seed
+from torch.utils.data import DataLoader
+
+from icefall.utils import str2bool
+
+
+class _SeedWorkers:
+    def __init__(self, seed: int):
+        self.seed = seed
+
+    def __call__(self, worker_id: int):
+        fix_random_seed(self.seed + worker_id)
+
+
+class LJSpeechTtsDataModule:
+    """
+    DataModule for tts experiments.
+    It assumes there is always one train and valid dataloader,
+    but there can be multiple test dataloaders (e.g. LibriSpeech test-clean
+    and test-other).
+
+    It contains all the common data pipeline modules used in ASR
+    experiments, e.g.:
+    - dynamic batch size,
+    - bucketing samplers,
+    - cut concatenation,
+    - on-the-fly feature extraction
+
+    This class should be derived for specific corpora used in ASR tasks.
+    """
+
+    def __init__(self, args: argparse.Namespace):
+        self.args = args
+
+    @classmethod
+    def add_arguments(cls, parser: argparse.ArgumentParser):
+        group = parser.add_argument_group(
+            title="TTS data related options",
+            description="These options are used for the preparation of "
+            "PyTorch DataLoaders from Lhotse CutSet's -- they control the "
+            "effective batch sizes, sampling strategies, applied data "
+            "augmentations, etc.",
+        )
+
+        group.add_argument(
+            "--manifest-dir",
+            type=Path,
+            default=Path("data/fbank"),
+            help="Path to directory with train/valid/test cuts.",
+        )
+        group.add_argument(
+            "--max-duration",
+            type=int,
+            default=200.0,
+            help="Maximum pooled recordings duration (seconds) in a "
+            "single batch. You can reduce it if it causes CUDA OOM.",
+        )
+        group.add_argument(
+            "--bucketing-sampler",
+            type=str2bool,
+            default=True,
+            help="When enabled, the batches will come from buckets of "
+            "similar duration (saves padding frames).",
+        )
+        group.add_argument(
+            "--num-buckets",
+            type=int,
+            default=30,
+            help="The number of buckets for the DynamicBucketingSampler"
+            "(you might want to increase it for larger datasets).",
+        )
+
+        group.add_argument(
+            "--on-the-fly-feats",
+            type=str2bool,
+            default=False,
+            help="When enabled, use on-the-fly cut mixing and feature "
+            "extraction. Will drop existing precomputed feature manifests "
+            "if available.",
+        )
+        group.add_argument(
+            "--shuffle",
+            type=str2bool,
+            default=True,
+            help="When enabled (=default), the examples will be "
+            "shuffled for each epoch.",
+        )
+        group.add_argument(
+            "--drop-last",
+            type=str2bool,
+            default=True,
+            help="Whether to drop last batch. Used by sampler.",
+        )
+        group.add_argument(
+            "--return-cuts",
+            type=str2bool,
+            default=False,
+            help="When enabled, each batch will have the "
+            "field: batch['cut'] with the cuts that "
+            "were used to construct it.",
+        )
+        group.add_argument(
+            "--num-workers",
+            type=int,
+            default=2,
+            help="The number of training dataloader workers that "
+            "collect the batches.",
+        )
+
+        group.add_argument(
+            "--input-strategy",
+            type=str,
+            default="PrecomputedFeatures",
+            help="AudioSamples or PrecomputedFeatures",
+        )
+
+    def train_dataloaders(
+        self,
+        cuts_train: CutSet,
+        sampler_state_dict: Optional[Dict[str, Any]] = None,
+    ) -> DataLoader:
+        """
+        Args:
+          cuts_train:
+            CutSet for training.
+          sampler_state_dict:
+            The state dict for the training sampler.
+        """
+        logging.info("About to create train dataset")
+        train = SpeechSynthesisDataset(
+            return_text=False,
+            return_tokens=True,
+            feature_input_strategy=eval(self.args.input_strategy)(),
+            return_cuts=self.args.return_cuts,
+        )
+
+        if self.args.on_the_fly_feats:
+            sampling_rate = 22050
+            config = MyFbankConfig(
+                n_fft=1024,
+                n_mels=80,
+                sampling_rate=sampling_rate,
+                hop_length=256,
+                win_length=1024,
+                f_min=0,
+                f_max=8000,
+            )
+            train = SpeechSynthesisDataset(
+                return_text=False,
+                return_tokens=True,
+                feature_input_strategy=OnTheFlyFeatures(MyFbank(config)),
+                return_cuts=self.args.return_cuts,
+            )
+
+        if self.args.bucketing_sampler:
+            logging.info("Using DynamicBucketingSampler.")
+            train_sampler = DynamicBucketingSampler(
+                cuts_train,
+                max_duration=self.args.max_duration,
+                shuffle=self.args.shuffle,
+                num_buckets=self.args.num_buckets,
+                buffer_size=self.args.num_buckets * 2000,
+                shuffle_buffer_size=self.args.num_buckets * 5000,
+                drop_last=self.args.drop_last,
+            )
+        else:
+            logging.info("Using SimpleCutSampler.")
+            train_sampler = SimpleCutSampler(
+                cuts_train,
+                max_duration=self.args.max_duration,
+                shuffle=self.args.shuffle,
+            )
+        logging.info("About to create train dataloader")
+
+        if sampler_state_dict is not None:
+            logging.info("Loading sampler state dict")
+            train_sampler.load_state_dict(sampler_state_dict)
+
+        # 'seed' is derived from the current random state, which will have
+        # previously been set in the main process.
+        seed = torch.randint(0, 100000, ()).item()
+        worker_init_fn = _SeedWorkers(seed)
+
+        train_dl = DataLoader(
+            train,
+            sampler=train_sampler,
+            batch_size=None,
+            num_workers=self.args.num_workers,
+            persistent_workers=True,
+            pin_memory=True,
+            worker_init_fn=worker_init_fn,
+        )
+
+        return train_dl
+
+    def valid_dataloaders(self, cuts_valid: CutSet) -> DataLoader:
+        logging.info("About to create dev dataset")
+        if self.args.on_the_fly_feats:
+            sampling_rate = 22050
+            config = MyFbankConfig(
+                n_fft=1024,
+                n_mels=80,
+                sampling_rate=sampling_rate,
+                hop_length=256,
+                win_length=1024,
+                f_min=0,
+                f_max=8000,
+            )
+            validate = SpeechSynthesisDataset(
+                return_text=False,
+                return_tokens=True,
+                feature_input_strategy=OnTheFlyFeatures(MyFbank(config)),
+                return_cuts=self.args.return_cuts,
+            )
+        else:
+            validate = SpeechSynthesisDataset(
+                return_text=False,
+                return_tokens=True,
+                feature_input_strategy=eval(self.args.input_strategy)(),
+                return_cuts=self.args.return_cuts,
+            )
+        valid_sampler = DynamicBucketingSampler(
+            cuts_valid,
+            max_duration=self.args.max_duration,
+            num_buckets=self.args.num_buckets,
+            shuffle=False,
+        )
+        logging.info("About to create valid dataloader")
+        valid_dl = DataLoader(
+            validate,
+            sampler=valid_sampler,
+            batch_size=None,
+            num_workers=2,
+            persistent_workers=True,
+            pin_memory=True,
+        )
+
+        return valid_dl
+
+    def test_dataloaders(self, cuts: CutSet) -> DataLoader:
+        logging.info("About to create test dataset")
+        if self.args.on_the_fly_feats:
+            sampling_rate = 22050
+            config = MyFbankConfig(
+                n_fft=1024,
+                n_mels=80,
+                sampling_rate=sampling_rate,
+                hop_length=256,
+                win_length=1024,
+                f_min=0,
+                f_max=8000,
+            )
+            test = SpeechSynthesisDataset(
+                return_text=False,
+                return_tokens=True,
+                feature_input_strategy=OnTheFlyFeatures(MyFbank(config)),
+                return_cuts=self.args.return_cuts,
+            )
+        else:
+            test = SpeechSynthesisDataset(
+                return_text=False,
+                return_tokens=True,
+                feature_input_strategy=eval(self.args.input_strategy)(),
+                return_cuts=self.args.return_cuts,
+            )
+        test_sampler = DynamicBucketingSampler(
+            cuts,
+            max_duration=self.args.max_duration,
+            num_buckets=self.args.num_buckets,
+            shuffle=False,
+        )
+        logging.info("About to create test dataloader")
+        test_dl = DataLoader(
+            test,
+            batch_size=None,
+            sampler=test_sampler,
+            num_workers=self.args.num_workers,
+        )
+        return test_dl
+
+    @lru_cache()
+    def train_cuts(self) -> CutSet:
+        logging.info("About to get train cuts")
+        return load_manifest_lazy(
+            self.args.manifest_dir / "ljspeech_cuts_train.jsonl.gz"
+        )
+
+    @lru_cache()
+    def valid_cuts(self) -> CutSet:
+        logging.info("About to get validation cuts")
+        return load_manifest_lazy(
+            self.args.manifest_dir / "ljspeech_cuts_valid.jsonl.gz"
+        )
+
+    @lru_cache()
+    def test_cuts(self) -> CutSet:
+        logging.info("About to get test cuts")
+        return load_manifest_lazy(
+            self.args.manifest_dir / "ljspeech_cuts_test.jsonl.gz"
+        )
diff --git a/egs/ljspeech/TTS/matcha/utils.py b/egs/ljspeech/TTS/matcha/utils.py
new file mode 120000
index 0000000000..c2144f8e07
--- /dev/null
+++ b/egs/ljspeech/TTS/matcha/utils.py
@@ -0,0 +1 @@
+../vits/utils.py
\ No newline at end of file
diff --git a/egs/ljspeech/TTS/prepare.sh b/egs/ljspeech/TTS/prepare.sh
index 9ed0f93fde..6f16f8d473 100755
--- a/egs/ljspeech/TTS/prepare.sh
+++ b/egs/ljspeech/TTS/prepare.sh
@@ -5,7 +5,7 @@ export PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python
 
 set -eou pipefail
 
-stage=0
+stage=-1
 stop_stage=100
 
 dl_dir=$PWD/download
@@ -31,7 +31,19 @@ if [ $stage -le -1 ] && [ $stop_stage -ge -1 ]; then
     python3 setup.py build_ext --inplace
     cd ../../
   else
-    log "monotonic_align lib already built"
+    log "monotonic_align lib for vits already built"
+  fi
+
+  if [ ! -f ./matcha/monotonic_align/core.cpython-38-x86_64-linux-gnu.so  ]; then
+    pushd matcha/monotonic_align
+    python3 setup.py build
+    mv -v build/lib.*/matcha/monotonic_align/core.*.so .
+    rm -rf build
+    rm core.c
+    ls -lh
+    popd
+  else
+    log "monotonic_align lib for matcha-tts already built"
   fi
 fi
 
@@ -63,7 +75,7 @@ if [ $stage -le 1 ] && [ $stop_stage -ge 1 ]; then
 fi
 
 if [ $stage -le 2 ] && [ $stop_stage -ge 2 ]; then
-  log "Stage 2: Compute spectrogram for LJSpeech"
+  log "Stage 2: Compute spectrogram for LJSpeech (used by ./vits)"
   mkdir -p data/spectrogram
   if [ ! -e data/spectrogram/.ljspeech.done ]; then
     ./local/compute_spectrogram_ljspeech.py
@@ -71,7 +83,7 @@ if [ $stage -le 2 ] && [ $stop_stage -ge 2 ]; then
   fi
 
   if [ ! -e data/spectrogram/.ljspeech-validated.done ]; then
-    log "Validating data/spectrogram for LJSpeech"
+    log "Validating data/spectrogram for LJSpeech (used by ./vits)"
     python3 ./local/validate_manifest.py \
       data/spectrogram/ljspeech_cuts_all.jsonl.gz
     touch data/spectrogram/.ljspeech-validated.done
@@ -79,13 +91,13 @@ if [ $stage -le 2 ] && [ $stop_stage -ge 2 ]; then
 fi
 
 if [ $stage -le 3 ] && [ $stop_stage -ge 3 ]; then
-  log "Stage 3: Prepare phoneme tokens for LJSpeech"
+  log "Stage 3: Prepare phoneme tokens for LJSpeech (used by ./vits)"
   # We assume you have installed piper_phonemize and espnet_tts_frontend.
   # If not, please install them with:
   #   - piper_phonemize: pip install piper_phonemize -f https://k2-fsa.github.io/icefall/piper_phonemize.html,
   #   - espnet_tts_frontend, `pip install espnet_tts_frontend`, refer to https://github.com/espnet/espnet_tts_frontend/
   if [ ! -e data/spectrogram/.ljspeech_with_token.done ]; then
-    ./local/prepare_tokens_ljspeech.py
+    ./local/prepare_tokens_ljspeech.py --in-out-dir ./data/spectrogram
     mv data/spectrogram/ljspeech_cuts_with_tokens_all.jsonl.gz \
       data/spectrogram/ljspeech_cuts_all.jsonl.gz
     touch data/spectrogram/.ljspeech_with_token.done
@@ -93,7 +105,7 @@ if [ $stage -le 3 ] && [ $stop_stage -ge 3 ]; then
 fi
 
 if [ $stage -le 4 ] && [ $stop_stage -ge 4 ]; then
-  log "Stage 4: Split the LJSpeech cuts into train, valid and test sets"
+  log "Stage 4: Split the LJSpeech cuts into train, valid and test sets (used by vits)"
   if [ ! -e data/spectrogram/.ljspeech_split.done ]; then
     lhotse subset --last 600 \
       data/spectrogram/ljspeech_cuts_all.jsonl.gz \
@@ -126,3 +138,63 @@ if [ $stage -le 5 ] && [ $stop_stage -ge 5 ]; then
     ./local/prepare_token_file.py --tokens data/tokens.txt
   fi
 fi
+
+if [ $stage -le 6 ] && [ $stop_stage -ge 6 ]; then
+  log "Stage 6: Generate fbank (used by ./matcha)"
+  mkdir -p data/fbank
+  if [ ! -e data/fbank/.ljspeech.done ]; then
+    ./local/compute_fbank_ljspeech.py
+    touch data/fbank/.ljspeech.done
+  fi
+
+  if [ ! -e data/fbank/.ljspeech-validated.done ]; then
+    log "Validating data/fbank for LJSpeech (used by ./matcha)"
+    python3 ./local/validate_manifest.py \
+      data/fbank/ljspeech_cuts_all.jsonl.gz
+    touch data/fbank/.ljspeech-validated.done
+  fi
+fi
+
+if [ $stage -le 7 ] && [ $stop_stage -ge 7 ]; then
+  log "Stage 7: Prepare phoneme tokens for LJSpeech (used by ./matcha)"
+  # We assume you have installed piper_phonemize and espnet_tts_frontend.
+  # If not, please install them with:
+  #   - piper_phonemize: pip install piper_phonemize -f https://k2-fsa.github.io/icefall/piper_phonemize.html,
+  #   - espnet_tts_frontend, `pip install espnet_tts_frontend`, refer to https://github.com/espnet/espnet_tts_frontend/
+  if [ ! -e data/fbank/.ljspeech_with_token.done ]; then
+    ./local/prepare_tokens_ljspeech.py --in-out-dir ./data/fbank
+    mv data/fbank/ljspeech_cuts_with_tokens_all.jsonl.gz \
+      data/fbank/ljspeech_cuts_all.jsonl.gz
+    touch data/fbank/.ljspeech_with_token.done
+  fi
+fi
+
+if [ $stage -le 8 ] && [ $stop_stage -ge 8 ]; then
+  log "Stage 8: Split the LJSpeech cuts into train, valid and test sets (used by ./matcha)"
+  if [ ! -e data/fbank/.ljspeech_split.done ]; then
+    lhotse subset --last 600 \
+      data/fbank/ljspeech_cuts_all.jsonl.gz \
+      data/fbank/ljspeech_cuts_validtest.jsonl.gz
+    lhotse subset --first 100 \
+      data/fbank/ljspeech_cuts_validtest.jsonl.gz \
+      data/fbank/ljspeech_cuts_valid.jsonl.gz
+    lhotse subset --last 500 \
+      data/fbank/ljspeech_cuts_validtest.jsonl.gz \
+      data/fbank/ljspeech_cuts_test.jsonl.gz
+
+    rm data/fbank/ljspeech_cuts_validtest.jsonl.gz
+
+    n=$(( $(gunzip -c data/fbank/ljspeech_cuts_all.jsonl.gz | wc -l) - 600 ))
+    lhotse subset --first $n  \
+      data/fbank/ljspeech_cuts_all.jsonl.gz \
+      data/fbank/ljspeech_cuts_train.jsonl.gz
+      touch data/fbank/.ljspeech_split.done
+  fi
+fi
+
+if [ $stage -le 9 ] && [ $stop_stage -ge 9 ]; then
+  log "Stage 9: Compute fbank mean and std (used by ./matcha)"
+  if [ ! -f ./data/fbank/cmvn.json ]; then
+    ./local/compute_fbank_statistics.py ./data/fbank/ljspeech_cuts_train.jsonl.gz ./data/fbank/cmvn.json
+  fi
+fi
diff --git a/icefall/checkpoint.py b/icefall/checkpoint.py
index 308a06b1f7..d31ce13019 100644
--- a/icefall/checkpoint.py
+++ b/icefall/checkpoint.py
@@ -90,7 +90,7 @@ def save_checkpoint(
 
     if params:
         for k, v in params.items():
-            assert k not in checkpoint
+            assert k not in checkpoint, k
             checkpoint[k] = v
 
     torch.save(checkpoint, filename)
diff --git a/icefall/decode.py b/icefall/decode.py
index dd3af1e99b..5d836bd480 100644
--- a/icefall/decode.py
+++ b/icefall/decode.py
@@ -1,4 +1,5 @@
-# Copyright      2021  Xiaomi Corp.        (authors: Fangjun Kuang)
+# Copyright      2021  Xiaomi Corp.        (authors: Fangjun Kuang,
+#                                                    Wei Kang)
 #
 # See ../../../../LICENSE for clarification regarding multiple authors
 #
@@ -15,11 +16,16 @@
 # limitations under the License.
 
 import logging
-from typing import Dict, List, Optional, Union
+from dataclasses import dataclass, field
+from multiprocessing.pool import Pool
+from typing import Dict, List, Optional, Tuple, Union
 
 import k2
 import torch
 
+from icefall.context_graph import ContextGraph, ContextState
+from icefall.lm_wrapper import LmScorer
+from icefall.ngram_lm import NgramLm, NgramLmStateCost
 from icefall.utils import add_eos, add_sos, get_texts
 
 DEFAULT_LM_SCALE = [
@@ -1497,3 +1503,667 @@ def ctc_greedy_search(
     hyps = [h[h != blank_id].tolist() for h in hyps]
 
     return hyps
+
+
+@dataclass
+class Hypothesis:
+    # The predicted tokens so far.
+    # Newly predicted tokens are appended to `ys`.
+    ys: List[int] = field(default_factory=list)
+
+    # The log prob of ys that ends with blank token.
+    # It contains only one entry.
+    log_prob_blank: torch.Tensor = torch.zeros(1, dtype=torch.float32)
+
+    # The log prob of ys that ends with non blank token.
+    # It contains only one entry.
+    log_prob_non_blank: torch.Tensor = torch.tensor(
+        [float("-inf")], dtype=torch.float32
+    )
+
+    # timestamp[i] is the frame index after subsampling
+    # on which ys[i] is decoded
+    timestamp: List[int] = field(default_factory=list)
+
+    # The lm score of ys
+    # May contain external LM score (including LODR score) and contextual biasing score
+    # It contains only one entry
+    lm_score: torch.Tensor = torch.zeros(1, dtype=torch.float32)
+
+    # the lm log_probs for next token given the history ys
+    # The number of elements should be equal to vocabulary size.
+    lm_log_probs: Optional[torch.Tensor] = None
+
+    # the RNNLM states (h and c in LSTM)
+    state: Optional[Tuple[torch.Tensor, torch.Tensor]] = None
+
+    # LODR (N-gram LM) state
+    LODR_state: Optional[NgramLmStateCost] = None
+
+    # N-gram LM state
+    Ngram_state: Optional[NgramLmStateCost] = None
+
+    # Context graph state
+    context_state: Optional[ContextState] = None
+
+    # This is the total score of current path, acoustic plus external LM score.
+    @property
+    def tot_score(self) -> torch.Tensor:
+        return self.log_prob + self.lm_score
+
+    # This is only the probability from model output (i.e External LM score not included).
+    @property
+    def log_prob(self) -> torch.Tensor:
+        return torch.logaddexp(self.log_prob_non_blank, self.log_prob_blank)
+
+    @property
+    def key(self) -> tuple:
+        """Return a tuple representation of self.ys"""
+        return tuple(self.ys)
+
+    def clone(self) -> "Hypothesis":
+        return Hypothesis(
+            ys=self.ys,
+            log_prob_blank=self.log_prob_blank,
+            log_prob_non_blank=self.log_prob_non_blank,
+            timestamp=self.timestamp,
+            lm_log_probs=self.lm_log_probs,
+            lm_score=self.lm_score,
+            state=self.state,
+            LODR_state=self.LODR_state,
+            Ngram_state=self.Ngram_state,
+            context_state=self.context_state,
+        )
+
+
+class HypothesisList(object):
+    def __init__(self, data: Optional[Dict[tuple, Hypothesis]] = None) -> None:
+        """
+        Args:
+          data:
+            A dict of Hypotheses. Its key is its `value.key`.
+        """
+        if data is None:
+            self._data = {}
+        else:
+            self._data = data
+
+    @property
+    def data(self) -> Dict[tuple, Hypothesis]:
+        return self._data
+
+    def add(self, hyp: Hypothesis) -> None:
+        """Add a Hypothesis to `self`.
+        If `hyp` already exists in `self`, its probability is updated using
+        `log-sum-exp` with the existed one.
+        Args:
+          hyp:
+            The hypothesis to be added.
+        """
+        key = hyp.key
+        if key in self:
+            old_hyp = self._data[key]  # shallow copy
+            torch.logaddexp(
+                old_hyp.log_prob_blank, hyp.log_prob_blank, out=old_hyp.log_prob_blank
+            )
+            torch.logaddexp(
+                old_hyp.log_prob_non_blank,
+                hyp.log_prob_non_blank,
+                out=old_hyp.log_prob_non_blank,
+            )
+        else:
+            self._data[key] = hyp
+
+    def get_most_probable(self, length_norm: bool = False) -> Hypothesis:
+        """Get the most probable hypothesis, i.e., the one with
+        the largest `tot_score`.
+        Args:
+          length_norm:
+            If True, the `tot_score` of a hypothesis is normalized by the
+            number of tokens in it.
+        Returns:
+          Return the hypothesis that has the largest `tot_score`.
+        """
+        if length_norm:
+            return max(self._data.values(), key=lambda hyp: hyp.tot_score / len(hyp.ys))
+        else:
+            return max(self._data.values(), key=lambda hyp: hyp.tot_score)
+
+    def remove(self, hyp: Hypothesis) -> None:
+        """Remove a given hypothesis.
+        Caution:
+          `self` is modified **in-place**.
+        Args:
+          hyp:
+            The hypothesis to be removed from `self`.
+            Note: It must be contained in `self`. Otherwise,
+            an exception is raised.
+        """
+        key = hyp.key
+        assert key in self, f"{key} does not exist"
+        del self._data[key]
+
+    def filter(self, threshold: torch.Tensor) -> "HypothesisList":
+        """Remove all Hypotheses whose tot_score is less than threshold.
+        Caution:
+          `self` is not modified. Instead, a new HypothesisList is returned.
+        Returns:
+          Return a new HypothesisList containing all hypotheses from `self`
+          with `tot_score` being greater than the given `threshold`.
+        """
+        ans = HypothesisList()
+        for _, hyp in self._data.items():
+            if hyp.tot_score > threshold:
+                ans.add(hyp)  # shallow copy
+        return ans
+
+    def topk(self, k: int, length_norm: bool = False) -> "HypothesisList":
+        """Return the top-k hypothesis.
+        Args:
+          length_norm:
+            If True, the `tot_score` of a hypothesis is normalized by the
+            number of tokens in it.
+        """
+        hyps = list(self._data.items())
+
+        if length_norm:
+            hyps = sorted(
+                hyps, key=lambda h: h[1].tot_score / len(h[1].ys), reverse=True
+            )[:k]
+        else:
+            hyps = sorted(hyps, key=lambda h: h[1].tot_score, reverse=True)[:k]
+
+        ans = HypothesisList(dict(hyps))
+        return ans
+
+    def __contains__(self, key: tuple):
+        return key in self._data
+
+    def __getitem__(self, key: tuple):
+        return self._data[key]
+
+    def __iter__(self):
+        return iter(self._data.values())
+
+    def __len__(self) -> int:
+        return len(self._data)
+
+    def __str__(self) -> str:
+        s = []
+        for key in self:
+            s.append(key)
+        return ", ".join(str(s))
+
+
+def get_hyps_shape(hyps: List[HypothesisList]) -> k2.RaggedShape:
+    """Return a ragged shape with axes [utt][num_hyps].
+    Args:
+      hyps:
+        len(hyps) == batch_size. It contains the current hypothesis for
+        each utterance in the batch.
+    Returns:
+      Return a ragged shape with 2 axes [utt][num_hyps]. Note that
+      the shape is on CPU.
+    """
+    num_hyps = [len(h) for h in hyps]
+
+    # torch.cumsum() is inclusive sum, so we put a 0 at the beginning
+    # to get exclusive sum later.
+    num_hyps.insert(0, 0)
+
+    num_hyps = torch.tensor(num_hyps)
+    row_splits = torch.cumsum(num_hyps, dim=0, dtype=torch.int32)
+    ans = k2.ragged.create_ragged_shape2(
+        row_splits=row_splits, cached_tot_size=row_splits[-1].item()
+    )
+    return ans
+
+
+def _step_worker(
+    log_probs: torch.Tensor,
+    indexes: torch.Tensor,
+    B: HypothesisList,
+    beam: int = 4,
+    blank_id: int = 0,
+    nnlm_scale: float = 0,
+    LODR_lm_scale: float = 0,
+    context_graph: Optional[ContextGraph] = None,
+) -> HypothesisList:
+    """The worker to decode one step.
+    Args:
+      log_probs:
+        topk log_probs of current step (i.e. the kept tokens of first pass pruning),
+        the shape is (beam,)
+      topk_indexes:
+        The indexes of the topk_values above, the shape is (beam,)
+      B:
+        An instance of HypothesisList containing the kept hypothesis.
+      beam:
+        The number of hypothesis to be kept at each step.
+      blank_id:
+        The id of blank in the vocabulary.
+      lm_scale:
+        The scale of nn lm.
+      LODR_lm_scale:
+        The scale of the LODR_lm
+      context_graph:
+        A ContextGraph instance containing contextual phrases.
+    Return:
+      Returns the updated HypothesisList.
+    """
+    A = list(B)
+    B = HypothesisList()
+    for h in range(len(A)):
+        hyp = A[h]
+        for k in range(log_probs.size(0)):
+            log_prob, index = log_probs[k], indexes[k]
+            new_token = index.item()
+            update_prefix = False
+            new_hyp = hyp.clone()
+            if new_token == blank_id:
+                # Case 0: *a + ε => *a
+                #         *aε + ε => *a
+                # Prefix does not change, update log_prob of blank
+                new_hyp.log_prob_non_blank = torch.tensor(
+                    [float("-inf")], dtype=torch.float32
+                )
+                new_hyp.log_prob_blank = hyp.log_prob + log_prob
+                B.add(new_hyp)
+            elif len(hyp.ys) > 0 and hyp.ys[-1] == new_token:
+                # Case 1: *a + a => *a
+                # Prefix does not change, update log_prob of non_blank
+                new_hyp.log_prob_non_blank = hyp.log_prob_non_blank + log_prob
+                new_hyp.log_prob_blank = torch.tensor(
+                    [float("-inf")], dtype=torch.float32
+                )
+                B.add(new_hyp)
+
+                # Case 2: *aε + a => *aa
+                # Prefix changes, update log_prob of blank
+                new_hyp = hyp.clone()
+                # Caution: DO NOT use append, as clone is shallow copy
+                new_hyp.ys = hyp.ys + [new_token]
+                new_hyp.log_prob_non_blank = hyp.log_prob_blank + log_prob
+                new_hyp.log_prob_blank = torch.tensor(
+                    [float("-inf")], dtype=torch.float32
+                )
+                update_prefix = True
+            else:
+                # Case 3: *a + b => *ab, *aε + b => *ab
+                # Prefix changes, update log_prob of non_blank
+                # Caution: DO NOT use append, as clone is shallow copy
+                new_hyp.ys = hyp.ys + [new_token]
+                new_hyp.log_prob_non_blank = hyp.log_prob + log_prob
+                new_hyp.log_prob_blank = torch.tensor(
+                    [float("-inf")], dtype=torch.float32
+                )
+                update_prefix = True
+
+            if update_prefix:
+                lm_score = hyp.lm_score
+                if hyp.lm_log_probs is not None:
+                    lm_score = lm_score + hyp.lm_log_probs[new_token] * nnlm_scale
+                    new_hyp.lm_log_probs = None
+
+                if context_graph is not None and hyp.context_state is not None:
+                    (
+                        context_score,
+                        new_context_state,
+                        matched_state,
+                    ) = context_graph.forward_one_step(hyp.context_state, new_token)
+                    lm_score = lm_score + context_score
+                    new_hyp.context_state = new_context_state
+
+                if hyp.LODR_state is not None:
+                    state_cost = hyp.LODR_state.forward_one_step(new_token)
+                    # calculate the score of the latest token
+                    current_ngram_score = state_cost.lm_score - hyp.LODR_state.lm_score
+                    assert current_ngram_score <= 0.0, (
+                        state_cost.lm_score,
+                        hyp.LODR_state.lm_score,
+                    )
+                    lm_score = lm_score + LODR_lm_scale * current_ngram_score
+                    new_hyp.LODR_state = state_cost
+
+                new_hyp.lm_score = lm_score
+                B.add(new_hyp)
+    B = B.topk(beam)
+    return B
+
+
+def _sequence_worker(
+    topk_values: torch.Tensor,
+    topk_indexes: torch.Tensor,
+    B: HypothesisList,
+    encoder_out_lens: torch.Tensor,
+    beam: int = 4,
+    blank_id: int = 0,
+) -> HypothesisList:
+    """The worker to decode one sequence.
+    Args:
+      topk_values:
+        topk log_probs of model output (i.e. the kept tokens of first pass pruning),
+        the shape is (T, beam)
+      topk_indexes:
+        The indexes of the topk_values above, the shape is (T, beam)
+      B:
+        An instance of HypothesisList containing the kept hypothesis.
+      encoder_out_lens:
+        The lengths (frames) of sequences after subsampling, the shape is (B,)
+      beam:
+        The number of hypothesis to be kept at each step.
+      blank_id:
+        The id of blank in the vocabulary.
+    Return:
+      Returns the updated HypothesisList.
+    """
+    B.add(Hypothesis())
+    for j in range(encoder_out_lens):
+        log_probs, indexes = topk_values[j], topk_indexes[j]
+        B = _step_worker(log_probs, indexes, B, beam, blank_id)
+    return B
+
+
+def ctc_prefix_beam_search(
+    ctc_output: torch.Tensor,
+    encoder_out_lens: torch.Tensor,
+    beam: int = 4,
+    blank_id: int = 0,
+    process_pool: Optional[Pool] = None,
+    return_nbest: Optional[bool] = False,
+) -> Union[List[List[int]], List[HypothesisList]]:
+    """Implement prefix search decoding in "Connectionist Temporal Classification:
+    Labelling Unsegmented Sequence Data with Recurrent Neural Networks".
+    Args:
+      ctc_output:
+        The output of ctc head (log probability), the shape is (B, T, V)
+      encoder_out_lens:
+        The lengths (frames) of sequences after subsampling, the shape is (B,)
+      beam:
+        The number of hypothesis to be kept at each step.
+      blank_id:
+        The id of blank in the vocabulary.
+      process_pool:
+        The process pool for parallel decoding, if not provided, it will use all
+        you cpu cores by default.
+      return_nbest:
+        If true, return a list of HypothesisList, return a list of list of decoded token ids otherwise.
+    """
+    batch_size, num_frames, vocab_size = ctc_output.shape
+
+    # TODO: using a larger beam for first pass pruning
+    topk_values, topk_indexes = ctc_output.topk(beam)  # (B, T, beam)
+    topk_values = topk_values.cpu()
+    topk_indexes = topk_indexes.cpu()
+
+    B = [HypothesisList() for _ in range(batch_size)]
+
+    pool = Pool() if process_pool is None else process_pool
+    arguments = []
+    for i in range(batch_size):
+        arguments.append(
+            (
+                topk_values[i],
+                topk_indexes[i],
+                B[i],
+                encoder_out_lens[i].item(),
+                beam,
+                blank_id,
+            )
+        )
+    async_results = pool.starmap_async(_sequence_worker, arguments)
+    B = list(async_results.get())
+    if process_pool is None:
+        pool.close()
+        pool.join()
+    if return_nbest:
+        return B
+    else:
+        best_hyps = [b.get_most_probable() for b in B]
+        return [hyp.ys for hyp in best_hyps]
+
+
+def ctc_prefix_beam_search_shallow_fussion(
+    ctc_output: torch.Tensor,
+    encoder_out_lens: torch.Tensor,
+    beam: int = 4,
+    blank_id: int = 0,
+    LODR_lm: Optional[NgramLm] = None,
+    LODR_lm_scale: Optional[float] = 0,
+    NNLM: Optional[LmScorer] = None,
+    context_graph: Optional[ContextGraph] = None,
+) -> List[List[int]]:
+    """Implement prefix search decoding in "Connectionist Temporal Classification:
+    Labelling Unsegmented Sequence Data with Recurrent Neural Networks" and add
+    nervous language model shallow fussion, it also supports contextual
+    biasing with a given grammar.
+    Args:
+      ctc_output:
+        The output of ctc head (log probability), the shape is (B, T, V)
+      encoder_out_lens:
+        The lengths (frames) of sequences after subsampling, the shape is (B,)
+      beam:
+        The number of hypothesis to be kept at each step.
+      blank_id:
+        The id of blank in the vocabulary.
+      LODR_lm:
+        A low order n-gram LM, whose score will be subtracted during shallow fusion
+      LODR_lm_scale:
+        The scale of the LODR_lm
+      LM:
+        A neural net LM, e.g an RNNLM or transformer LM
+      context_graph:
+        A ContextGraph instance containing contextual phrases.
+    Return:
+      Returns a list of list of decoded token ids.
+    """
+    batch_size, num_frames, vocab_size = ctc_output.shape
+    # TODO: using a larger beam for first pass pruning
+    topk_values, topk_indexes = ctc_output.topk(beam)  # (B, T, beam)
+    topk_values = topk_values.cpu()
+    topk_indexes = topk_indexes.cpu()
+    encoder_out_lens = encoder_out_lens.tolist()
+    device = ctc_output.device
+
+    nnlm_scale = 0
+    init_scores = None
+    init_states = None
+    if NNLM is not None:
+        nnlm_scale = NNLM.lm_scale
+        sos_id = getattr(NNLM, "sos_id", 1)
+        # get initial lm score and lm state by scoring the "sos" token
+        sos_token = torch.tensor([[sos_id]]).to(torch.int64).to(device)
+        lens = torch.tensor([1]).to(device)
+        init_scores, init_states = NNLM.score_token(sos_token, lens)
+        init_scores, init_states = init_scores.cpu(), (
+            init_states[0].cpu(),
+            init_states[1].cpu(),
+        )
+
+    B = [HypothesisList() for _ in range(batch_size)]
+    for i in range(batch_size):
+        B[i].add(
+            Hypothesis(
+                ys=[],
+                log_prob_non_blank=torch.tensor([float("-inf")], dtype=torch.float32),
+                log_prob_blank=torch.zeros(1, dtype=torch.float32),
+                lm_score=torch.zeros(1, dtype=torch.float32),
+                state=init_states,
+                lm_log_probs=None if init_scores is None else init_scores.reshape(-1),
+                LODR_state=None if LODR_lm is None else NgramLmStateCost(LODR_lm),
+                context_state=None if context_graph is None else context_graph.root,
+            )
+        )
+    for j in range(num_frames):
+        for i in range(batch_size):
+            if j < encoder_out_lens[i]:
+                log_probs, indexes = topk_values[i][j], topk_indexes[i][j]
+                B[i] = _step_worker(
+                    log_probs=log_probs,
+                    indexes=indexes,
+                    B=B[i],
+                    beam=beam,
+                    blank_id=blank_id,
+                    nnlm_scale=nnlm_scale,
+                    LODR_lm_scale=LODR_lm_scale,
+                    context_graph=context_graph,
+                )
+        if NNLM is None:
+            continue
+        # update lm_log_probs
+        token_list = []  # a list of list
+        hs = []
+        cs = []
+        indexes = []  # (batch_idx, key)
+        for batch_idx, hyps in enumerate(B):
+            for hyp in hyps:
+                if hyp.lm_log_probs is None:  # those hyps that prefix changes
+                    if NNLM.lm_type == "rnn":
+                        token_list.append([hyp.ys[-1]])
+                        # store the LSTM states
+                        hs.append(hyp.state[0])
+                        cs.append(hyp.state[1])
+                    else:
+                        # for transformer LM
+                        token_list.append([sos_id] + hyp.ys[:])
+                    indexes.append((batch_idx, hyp.key))
+        if len(token_list) != 0:
+            x_lens = torch.tensor([len(tokens) for tokens in token_list]).to(device)
+            if NNLM.lm_type == "rnn":
+                tokens_to_score = (
+                    torch.tensor(token_list).to(torch.int64).to(device).reshape(-1, 1)
+                )
+                hs = torch.cat(hs, dim=1).to(device)
+                cs = torch.cat(cs, dim=1).to(device)
+                state = (hs, cs)
+            else:
+                # for transformer LM
+                tokens_list = [torch.tensor(tokens) for tokens in token_list]
+                tokens_to_score = (
+                    torch.nn.utils.rnn.pad_sequence(
+                        tokens_list, batch_first=True, padding_value=0.0
+                    )
+                    .to(device)
+                    .to(torch.int64)
+                )
+                state = None
+
+            scores, lm_states = NNLM.score_token(tokens_to_score, x_lens, state)
+            scores, lm_states = scores.cpu(), (lm_states[0].cpu(), lm_states[1].cpu())
+            assert scores.size(0) == len(indexes), (scores.size(0), len(indexes))
+            for i in range(scores.size(0)):
+                batch_idx, key = indexes[i]
+                B[batch_idx][key].lm_log_probs = scores[i]
+                if NNLM.lm_type == "rnn":
+                    state = (
+                        lm_states[0][:, i, :].unsqueeze(1),
+                        lm_states[1][:, i, :].unsqueeze(1),
+                    )
+                    B[batch_idx][key].state = state
+
+    # finalize context_state, if the matched contexts do not reach final state
+    # we need to add the score on the corresponding backoff arc
+    if context_graph is not None:
+        for hyps in B:
+            for hyp in hyps:
+                context_score, new_context_state = context_graph.finalize(
+                    hyp.context_state
+                )
+                hyp.lm_score += context_score
+                hyp.context_state = new_context_state
+
+    best_hyps = [b.get_most_probable() for b in B]
+    return [hyp.ys for hyp in best_hyps]
+
+
+def ctc_prefix_beam_search_attention_decoder_rescoring(
+    ctc_output: torch.Tensor,
+    attention_decoder: torch.nn.Module,
+    encoder_out: torch.Tensor,
+    encoder_out_lens: torch.Tensor,
+    beam: int = 8,
+    blank_id: int = 0,
+    attention_scale: Optional[float] = None,
+    process_pool: Optional[Pool] = None,
+):
+    """Implement prefix search decoding in "Connectionist Temporal Classification:
+    Labelling Unsegmented Sequence Data with Recurrent Neural Networks" and add
+    attention decoder rescoring.
+    Args:
+      ctc_output:
+        The output of ctc head (log probability), the shape is (B, T, V)
+      attention_decoder:
+        The attention decoder.
+      encoder_out:
+        The output of encoder, the shape is (B, T, D)
+      encoder_out_lens:
+        The lengths (frames) of sequences after subsampling, the shape is (B,)
+      beam:
+        The number of hypothesis to be kept at each step.
+      blank_id:
+        The id of blank in the vocabulary.
+      attention_scale:
+        The scale of attention decoder score, if not provided it will search in
+        a default list (see the code below).
+      process_pool:
+        The process pool for parallel decoding, if not provided, it will use all
+        you cpu cores by default.
+    """
+    # List[HypothesisList]
+    nbest = ctc_prefix_beam_search(
+        ctc_output=ctc_output,
+        encoder_out_lens=encoder_out_lens,
+        beam=beam,
+        blank_id=blank_id,
+        return_nbest=True,
+    )
+
+    device = ctc_output.device
+
+    hyp_shape = get_hyps_shape(nbest).to(device)
+    hyp_to_utt_map = hyp_shape.row_ids(1).to(torch.long)
+    # the shape of encoder_out is (N, T, C), so we use axis=0 here
+    expanded_encoder_out = encoder_out.index_select(0, hyp_to_utt_map)
+    expanded_encoder_out_lens = encoder_out_lens.index_select(0, hyp_to_utt_map)
+
+    nbest = [list(x) for x in nbest]
+    token_ids = []
+    scores = []
+    for hyps in nbest:
+        for hyp in hyps:
+            token_ids.append(hyp.ys)
+            scores.append(hyp.log_prob.reshape(1))
+    scores = torch.cat(scores).to(device)
+
+    nll = attention_decoder.nll(
+        encoder_out=expanded_encoder_out,
+        encoder_out_lens=expanded_encoder_out_lens,
+        token_ids=token_ids,
+    )
+    assert nll.ndim == 2
+    assert nll.shape[0] == len(token_ids)
+
+    attention_scores = -nll.sum(dim=1)
+
+    if attention_scale is None:
+        attention_scale_list = [0.01, 0.05, 0.08]
+        attention_scale_list += [0.1, 0.3, 0.5, 0.6, 0.7, 0.9, 1.0]
+        attention_scale_list += [1.1, 1.2, 1.3, 1.5, 1.7, 1.9, 2.0]
+        attention_scale_list += [2.1, 2.2, 2.3, 2.5, 3.0, 4.0, 5.0]
+        attention_scale_list += [5.0, 6.0, 7.0, 8.0, 9.0]
+    else:
+        attention_scale_list = [attention_scale]
+
+    ans = dict()
+
+    start_indexes = hyp_shape.row_splits(1)[0:-1]
+    for a_scale in attention_scale_list:
+        tot_scores = scores + a_scale * attention_scores
+        ragged_tot_scores = k2.RaggedTensor(hyp_shape, tot_scores)
+        max_indexes = ragged_tot_scores.argmax()
+        max_indexes = max_indexes - start_indexes
+        max_indexes = max_indexes.cpu()
+        best_path = [nbest[i][max_indexes[i]].ys for i in range(len(max_indexes))]
+        key = f"attention_scale_{a_scale}"
+        ans[key] = best_path
+    return ans
diff --git a/icefall/utils.py b/icefall/utils.py
index 0682252f95..41eebadd46 100644
--- a/icefall/utils.py
+++ b/icefall/utils.py
@@ -19,8 +19,10 @@
 
 import argparse
 import collections
+import json
 import logging
 import os
+import pathlib
 import random
 import re
 import subprocess
@@ -180,6 +182,15 @@ def __delattr__(self, key):
             return
         raise AttributeError(f"No such attribute '{key}'")
 
+    def __str__(self, indent: int = 2):
+        tmp = {}
+        for k, v in self.items():
+            # PosixPath is ont JSON serializable
+            if isinstance(v, pathlib.Path) or isinstance(v, torch.device):
+                v = str(v)
+            tmp[k] = v
+        return json.dumps(tmp, indent=indent, sort_keys=True)
+
 
 def encode_supervisions(
     supervisions: dict,