Handle keyframe request it in the encoder and use x264 defaults

c_src/membrane_h264_ffmpeg_plugin/encoder.c

@@ -72,6 +72,16 @@ UNIFEX_TERM create(UnifexEnv *env, int width, int height, char *pix_fmt,
 
   av_dict_set_int(&params, "sc_threshold", sc_threshold, 0);
 
+  av_dict_set(&params, "qcomp", "0.6", 0);
+  av_dict_set(&params, "me_range", "16", 0);
+  av_dict_set(&params, "qdiff", "4", 0);
+  av_dict_set(&params, "qmin", "0", 0);
+  av_dict_set(&params, "qmax", "69", 0);
+  av_dict_set(&params, "i_qfactor", "1.4", 0);
+  av_dict_set(&params, "f_pb_factor", "1.3", 0);
+  av_dict_set(&params, "partitions", "p8x8,b8x8,i8x8,i4x4", 0);
+  av_dict_set(&params, "subq", "2", 0);
+
   if (avcodec_open2(state->codec_ctx, codec, &params) < 0) {
     res = create_result_error(env, "codec_open");
     goto exit_create;
@@ -153,7 +163,7 @@ static int get_frames(UnifexEnv *env, AVFrame *frame,
 }
 
 UNIFEX_TERM encode(UnifexEnv *env, UnifexPayload *payload, int64_t pts,
-                   int use_shm, State *state) {
+                   int use_shm, int keyframe_requested, State *state) {
   UNIFEX_TERM res_term;
   int res = 0;
   int max_frames = 16, frame_cnt = 0;
@@ -165,6 +175,9 @@ UNIFEX_TERM encode(UnifexEnv *env, UnifexPayload *payload, int64_t pts,
   frame->format = state->codec_ctx->pix_fmt;
   frame->width = state->codec_ctx->width;
   frame->height = state->codec_ctx->height;
+  if(keyframe_requested) {
+    frame->pict_type = AV_PICTURE_TYPE_I;
+  }
   av_image_fill_arrays(frame->data, frame->linesize, payload->data,
                        frame->format, frame->width, frame->height, 1);
 

c_src/membrane_h264_ffmpeg_plugin/encoder.spec.exs

@@ -19,7 +19,7 @@ spec create(
 
 spec get_frame_size(state) :: {:ok :: label, frame_size :: int} | {:error :: label}
 
-spec encode(payload, pts :: int64, use_shm :: bool, state) ::
+spec encode(payload, pts :: int64, use_shm :: bool, keyframe_requested :: bool, state) ::
        {:ok :: label, dts_list :: [int64], pts_list :: [int64], [payload]}
        | {:error :: label, reason :: atom}
 

lib/membrane_h264_ffmpeg/encoder.ex

@@ -128,6 +128,7 @@ defmodule Membrane.H264.FFmpeg.Encoder do
     state =
       opts
       |> Map.put(:encoder_ref, nil)
+      |> Map.put(:keyframe_requested?, false)
 
     {[], state}
   end
@@ -141,12 +142,13 @@ defmodule Membrane.H264.FFmpeg.Encoder do
            buffer.payload,
            pts,
            use_shm?,
+           state.keyframe_requested?,
            encoder_ref
          ) do
       {:ok, dts_list, pts_list, frames} ->
         bufs = wrap_frames(dts_list, pts_list, frames)
 
-        {bufs, state}
+        {bufs, %{state | keyframe_requested?: false}}
 
       {:error, reason} ->
         raise "Native encoder failed to encode the payload: #{inspect(reason)}"
@@ -194,6 +196,21 @@ defmodule Membrane.H264.FFmpeg.Encoder do
     {actions, state}
   end
 
+  @impl true
+  def handle_event(:input, event, _ctx, state) do
+    {[event: {:output, event}], state}
+  end
+
+  @impl true
+  def handle_event(:output, %Membrane.KeyframeRequestEvent{}, _ctx, state) do
+    {[], %{state | keyframe_requested?: true}}
+  end
+
+  @impl true
+  def handle_event(:output, event, _ctx, state) do
+    {[event: {:input, event}], state}
+  end
+
   defp flush_encoder_if_exists(%{encoder_ref: nil}), do: []
 
   defp flush_encoder_if_exists(%{encoder_ref: encoder_ref, use_shm?: use_shm?}) do

test/encoder/encoder_native_test.exs

@@ -20,7 +20,8 @@ defmodule Encoder.NativeTest do
                  Enc.encode(
                    frame,
                    Common.to_h264_time_base_truncated(seconds(timestamp)),
-                   false,
+                   _use_shm? = false,
+                   _keyframe_requested? = false,
                    ref
                  )
       end