Support video-only streams if there is no audio in the inbound stream. (#401)

Closes #400

core/ffmpeg/transcoder.go

@@ -27,6 +27,7 @@ type Transcoder struct {
 	ffmpegPath           string
 	segmentIdentifier    string
 	internalListenerPort int
+	videoOnly            bool // If true ignore any audio, if any
 	TranscoderCompleted  func(error)
 }
 
@@ -80,6 +81,9 @@ func (t *Transcoder) Start() {
 	command := t.getString()
 
 	log.Tracef("Video transcoder started with %d stream variants.", len(t.variants))
+	if t.videoOnly {
+		log.Tracef("Transcoder requested to operate on video only, ignoring audio.")
+	}
 
 	if config.Config.EnableDebugFeatures {
 		log.Println(command)
@@ -252,7 +256,14 @@ func (t *Transcoder) getVariantsString() string {
 
 	for _, variant := range t.variants {
 		variantsCommandFlags = variantsCommandFlags + " " + variant.getVariantString(t)
-		variantsStreamMaps = variantsStreamMaps + fmt.Sprintf("v:%d,a:%d ", variant.index, variant.index)
+		singleVariantMap := ""
+		if t.videoOnly {
+			singleVariantMap = fmt.Sprintf("v:%d ", variant.index)
+		} else {
+			singleVariantMap = fmt.Sprintf("v:%d,a:%d ", variant.index, variant.index)
+		}
+
+		variantsStreamMaps = variantsStreamMaps + singleVariantMap
 	}
 	variantsCommandFlags = variantsCommandFlags + " " + variantsStreamMaps + "\""
 
@@ -339,12 +350,12 @@ func (v *HLSVariant) SetAudioBitrate(bitrate string) {
 
 func (v *HLSVariant) getAudioQualityString() string {
 	if v.isAudioPassthrough {
-		return fmt.Sprintf("-map a:0 -c:a:%d copy", v.index)
+		return fmt.Sprintf("-map a:0? -c:a:%d copy", v.index)
 	}
 
 	// libfdk_aac is not a part of every ffmpeg install, so use "aac" instead
 	encoderCodec := "aac"
-	return fmt.Sprintf("-map a:0 -c:a:%d %s -b:a:%d %s", v.index, encoderCodec, v.index, v.audioBitrate)
+	return fmt.Sprintf("-map a:0? -c:a:%d %s -b:a:%d %s", v.index, encoderCodec, v.index, v.audioBitrate)
 }
 
 // AddVariant adds a new HLS variant to include in the output.
@@ -386,3 +397,8 @@ func (t *Transcoder) SetIdentifier(output string) {
 func (t *Transcoder) SetInternalHTTPPort(port int) {
 	t.internalListenerPort = port
 }
+
+// SetVideoOnly will ignore any audio streams, if any.
+func (t *Transcoder) SetVideoOnly(videoOnly bool) {
+	t.videoOnly = videoOnly
+}

core/ffmpeg/transcoder_test.go

@@ -35,7 +35,7 @@ func TestFFmpegCommand(t *testing.T) {
 
 	cmd := transcoder.getString()
 
-	expected := `/fake/path/ffmpeg -hide_banner -loglevel warning -i  fakecontent.flv  -map v:0 -c:v:0 libx264 -b:v:0 1200k -maxrate:v:0 1272k -bufsize:v:0 1440k -g:v:0 119 -profile:v:0 high -r:v:0 30 -x264-params:v:0 "scenecut=0:open_gop=0:min-keyint=119:keyint=119" -map a:0 -c:a:0 copy -preset veryfast -map v:0 -c:v:1 libx264 -b:v:1 3500k -maxrate:v:1 3710k -bufsize:v:1 4200k -g:v:1 95 -profile:v:1 high -r:v:1 24 -x264-params:v:1 "scenecut=0:open_gop=0:min-keyint=95:keyint=95" -map a:0 -c:a:1 copy -preset faster -map v:0 -c:v:2 copy -map a:0 -c:a:2 copy  -var_stream_map "v:0,a:0 v:1,a:1 v:2,a:2 " -f hls -hls_time 4 -hls_list_size 10 -hls_delete_threshold 10  -tune zerolatency -pix_fmt yuv420p -sc_threshold 0 -master_pl_name stream.m3u8 -strftime 1 -hls_segment_filename http://127.0.0.1:8123/%v/stream-jdofFGg%s.ts -max_muxing_queue_size 400 -method PUT -http_persistent 0 -fflags +genpts http://127.0.0.1:8123/%v/stream.m3u8 2> transcoder.log`
+	expected := `/fake/path/ffmpeg -hide_banner -loglevel warning -i  fakecontent.flv  -map v:0 -c:v:0 libx264 -b:v:0 1200k -maxrate:v:0 1272k -bufsize:v:0 1440k -g:v:0 119 -profile:v:0 high -r:v:0 30 -x264-params:v:0 "scenecut=0:open_gop=0:min-keyint=119:keyint=119" -map a:0? -c:a:0 copy -preset veryfast -map v:0 -c:v:1 libx264 -b:v:1 3500k -maxrate:v:1 3710k -bufsize:v:1 4200k -g:v:1 95 -profile:v:1 high -r:v:1 24 -x264-params:v:1 "scenecut=0:open_gop=0:min-keyint=95:keyint=95" -map a:0? -c:a:1 copy -preset faster -map v:0 -c:v:2 copy -map a:0? -c:a:2 copy  -var_stream_map "v:0,a:0 v:1,a:1 v:2,a:2 " -f hls -hls_time 4 -hls_list_size 10 -hls_delete_threshold 10  -tune zerolatency -pix_fmt yuv420p -sc_threshold 0 -master_pl_name stream.m3u8 -strftime 1 -hls_segment_filename http://127.0.0.1:8123/%v/stream-jdofFGg%s.ts -max_muxing_queue_size 400 -method PUT -http_persistent 0 -fflags +genpts http://127.0.0.1:8123/%v/stream.m3u8 2> transcoder.log`
 
 	if cmd != expected {
 		t.Errorf("ffmpeg command does not match expected.\nGot %s\n, want: %s", cmd, expected)

core/rtmp/broadcaster.go

@@ -27,6 +27,7 @@ func setCurrentBroadcasterInfo(t flvio.Tag, remoteAddr string) {
 			AudioBitrate:   int(data.AudioBitrate),
 			AudioCodec:     getAudioCodec(data.AudioCodec),
 			Encoder:        data.Encoder,
+			VideoOnly:      data.AudioCodec == nil,
 		},
 	}
 

core/rtmp/rtmp.go

@@ -70,6 +70,7 @@ func HandleConn(c *rtmp.Conn, nc net.Conn) {
 		if t.Type == flvio.TAG_AMF0 {
 			log.Tracef("%+v\n", t.DebugFields())
 			setCurrentBroadcasterInfo(t, nc.RemoteAddr().String())
+			_setStreamAsConnected()
 		}
 	}
 
@@ -98,7 +99,6 @@ func HandleConn(c *rtmp.Conn, nc net.Conn) {
 	}
 
 	_hasInboundRTMPConnection = true
-	_setStreamAsConnected()
 	_rtmpConnection = nc
 
 	f, err := os.OpenFile(pipePath, os.O_RDWR, os.ModeNamedPipe)

core/rtmp/utils.go

@@ -30,6 +30,10 @@ func getInboundDetailsFromMetadata(metadata []interface{}) (models.RTMPStreamMet
 }
 
 func getAudioCodec(codec interface{}) string {
+	if codec == nil {
+		return "No audio"
+	}
+
 	var codecID float64
 	if assertedCodecID, ok := codec.(float64); ok {
 		codecID = assertedCodecID

core/streamState.go

@@ -43,6 +43,7 @@ func setStreamAsConnected() {
 
 	go func() {
 		_transcoder = ffmpeg.NewTranscoder()
+		_transcoder.SetVideoOnly(_broadcaster.StreamDetails.VideoOnly)
 		_transcoder.TranscoderCompleted = func(error) {
 			SetStreamAsDisconnected()
 		}

models/broadcaster.go

@@ -18,6 +18,7 @@ type InboundStreamDetails struct {
 	AudioBitrate   int     `json:"audioBitrate"`
 	AudioCodec     string  `json:"audioCodec"`
 	Encoder        string  `json:"encoder"`
+	VideoOnly      bool    `json:"-"`
 }
 
 // RTMPStreamMetadata is the raw metadata that comes in with a RTMP connection.