ffmpeg: Add a metadata option to each output (#421)

This will allow us to identify the software version and
who transcoded a given segment.

ffmpeg/encoder.c

@@ -286,6 +286,8 @@ int open_output(struct output_ctx *octx, struct input_ctx *ictx)
     if (ret < 0) LPMS_ERR(open_output_err, "Error opening output file");
   }
 
+  if (octx->metadata) av_dict_copy(&oc->metadata, octx->metadata, 0);
+
   ret = avformat_write_header(oc, &octx->muxer->opts);
   if (ret < 0) LPMS_ERR(open_output_err, "Error writing header");
 
@@ -324,6 +326,8 @@ int reopen_output(struct output_ctx *octx, struct input_ctx *ictx)
     ret = avio_open(&octx->oc->pb, octx->fname, AVIO_FLAG_WRITE);
     if (ret < 0) LPMS_ERR(reopen_out_err, "Error re-opening output file");
   }
+
+  if (octx->metadata) av_dict_copy(&octx->oc->metadata, octx->metadata, 0);
   ret = avformat_write_header(octx->oc, &octx->muxer->opts);
   if (ret < 0) LPMS_ERR(reopen_out_err, "Error re-writing header");
 

ffmpeg/ffmpeg.go

@@ -112,6 +112,7 @@ type TranscodeOptions struct {
 	Muxer        ComponentOptions
 	VideoEncoder ComponentOptions
 	AudioEncoder ComponentOptions
+	Metadata     map[string]string
 }
 
 type MediaInfo struct {
@@ -778,6 +779,7 @@ func createCOutputParams(input *TranscodeOptionsIn, ps []TranscodeOptions) ([]C.
 			name: C.CString(audioEncoder),
 			opts: newAVOpts(p.AudioEncoder.Opts),
 		}
+		metadata := newAVOpts(p.Metadata)
 		fromMs := int(p.From.Milliseconds())
 		toMs := int(p.To.Milliseconds())
 		vfilt := C.CString(filters)
@@ -786,7 +788,7 @@ func createCOutputParams(input *TranscodeOptionsIn, ps []TranscodeOptions) ([]C.
 		params[i] = C.output_params{fname: oname, fps: fps,
 			w: C.int(w), h: C.int(h), bitrate: C.int(bitrate),
 			gop_time: C.int(gopMs), from: C.int(fromMs), to: C.int(toMs),
-			muxer: muxOpts, audio: audioOpts, video: vidOpts,
+			muxer: muxOpts, audio: audioOpts, video: vidOpts, metadata: metadata,
 			vfilters: vfilt, sfilters: nil, xcoderParams: xcoderOutParams}
 		if p.CalcSign {
 			//signfilter string
@@ -841,6 +843,9 @@ func destroyCOutputParams(params []C.output_params) {
 		if p.video.opts != nil {
 			C.av_dict_free(&p.video.opts)
 		}
+		if p.metadata != nil {
+			C.av_dict_free(&p.metadata)
+		}
 	}
 }
 

ffmpeg/ffmpeg_test.go

@@ -1628,6 +1628,9 @@ func TestTranscoder_FormatOptions(t *testing.T) {
 		Oname:        dir + "/test.flv",
 		VideoEncoder: ComponentOptions{Name: "copy"},
 		AudioEncoder: ComponentOptions{Name: "copy"},
+		Metadata: map[string]string{
+			"encoded_by": "Livepeer Media Server",
+		},
 	}}
 	if out[0].Profile.Format != FormatNone {
 		t.Error("Expected empty profile for output option")
@@ -1637,7 +1640,7 @@ func TestTranscoder_FormatOptions(t *testing.T) {
 		t.Error(err)
 	}
 	cmd = `
-        ffprobe -loglevel warning -show_format test.flv | grep format_name=flv
+        ffprobe -loglevel warning -show_format test.flv | grep 'format_name=flv\|encoded_by=Livepeer Media Server'
     `
 	run(cmd)
 
@@ -1646,6 +1649,9 @@ func TestTranscoder_FormatOptions(t *testing.T) {
 	out[0].Muxer = ComponentOptions{Name: "hls", Opts: map[string]string{
 		"hls_segment_filename": dir + "/test_segment_%d.ts",
 	}}
+	out[0].Metadata = map[string]string{
+		"service_provider": "Livepeer Media Server",
+	}
 	_, err = Transcode3(in, out)
 	if err != nil {
 		t.Error(err)
@@ -1660,6 +1666,7 @@ func TestTranscoder_FormatOptions(t *testing.T) {
         ffprobe -loglevel warning -show_entries format=format_name,duration test.ts > test.out
         diff -u segment.out test.out
         wc -l test.out | grep 4 # sanity check output file length
+        ffprobe segment.ts 2>&1 | grep 'service_provider: Livepeer Media Server'
     `
 	run(cmd)
 
@@ -1752,6 +1759,50 @@ func TestTranscoder_FormatOptions(t *testing.T) {
 	}
 }
 
+func TestTranscoder_Metadata(t *testing.T) {
+	runTestTranscoder_Metadata(t, Software)
+}
+
+func runTestTranscoder_Metadata(t *testing.T, accel Acceleration) {
+	// check that metadata is there in all segments
+	run, dir := setupTest(t)
+	defer os.RemoveAll(dir)
+
+	err := RTMPToHLS("../transcoder/test.ts", dir+"/in.m3u8", dir+"/in_%d.ts", "2", 0)
+	if err != nil {
+		t.Error(err)
+	}
+	tc := NewTranscoder()
+	defer tc.StopTranscoder()
+	for i := 0; i < 4; i++ {
+		in := &TranscodeOptionsIn{
+			Fname: fmt.Sprintf("%s/in_%d.ts", dir, i),
+			Accel: accel,
+		}
+		out := []TranscodeOptions{{
+			Accel:   accel,
+			Oname:   fmt.Sprintf("%s/out_%d.ts", dir, i),
+			Profile: P144p30fps16x9,
+			Metadata: map[string]string{
+				"service_name": fmt.Sprintf("lpms-test-%d", i),
+			},
+		}}
+		_, err := tc.Transcode(in, out)
+		if err != nil {
+			t.Error(err)
+		}
+	}
+
+	cmd := `
+		ffprobe -hide_banner -i out_1.ts
+		ffprobe -i out_0.ts 2>&1 | grep 'service_name    : lpms-test-0'
+		ffprobe -i out_1.ts 2>&1 | grep 'service_name    : lpms-test-1'
+		ffprobe -i out_2.ts 2>&1 | grep 'service_name    : lpms-test-2'
+		ffprobe -i out_3.ts 2>&1 | grep 'service_name    : lpms-test-3'
+	`
+	run(cmd)
+}
+
 func TestTranscoder_IgnoreUnknown(t *testing.T) {
 	run, dir := setupTest(t)
 	defer os.RemoveAll(dir)

ffmpeg/filter.h

@@ -65,6 +65,7 @@ struct output_ctx {
   component_opts *muxer;
   component_opts *video;
   component_opts *audio;
+  AVDictionary   *metadata;
 
   int64_t drop_ts;     // preroll audio ts to drop
 

ffmpeg/nvidia_test.go

@@ -801,3 +801,8 @@ func TestNvidia_DiscontinuityAudioSegment(t *testing.T) {
 func TestNvidia_Rotation(t *testing.T) {
 	runRotationTests(t, Nvidia)
 }
+
+func TestNvidia_Metadata(t *testing.T) {
+	// with nvenc we reopen the outputs so exercise that
+	runTestTranscoder_Metadata(t, Nvidia)
+}

ffmpeg/transcoder.c

@@ -216,6 +216,7 @@ int transcode_init(struct transcode_thread *h, input_params *inp,
     octx->muxer = &params[i].muxer;
     octx->audio = &params[i].audio;
     octx->video = &params[i].video;
+    octx->metadata = params[i].metadata;
     octx->vfilters = params[i].vfilters;
     octx->sfilters = params[i].sfilters;
     octx->xcoderParams = params[i].xcoderParams;

ffmpeg/transcoder.h

@@ -35,6 +35,7 @@ typedef struct {
   component_opts muxer;
   component_opts audio;
   component_opts video;
+  AVDictionary *metadata;
 } output_params;
 
 typedef struct {