replace video track on demand.

internal/types/event/events.go

@@ -11,6 +11,7 @@ const (
 	SIGNAL_ANSWER    = "signal/answer"
 	SIGNAL_PROVIDE   = "signal/provide"
 	SIGNAL_CANDIDATE = "signal/candidate"
+	SIGNAL_VIDEO     = "signal/video"
 )
 
 const (

internal/types/message/messages.go

@@ -57,6 +57,11 @@ type SignalAnswer struct {
 	SDP   string `json:"sdp"`
 }
 
+type SignalVideo struct {
+	Event   string `json:"event,omitempty"`
+	VideoID string `json:"video_id"`
+}
+
 /////////////////////////////
 // Member
 /////////////////////////////

internal/webrtc/manager.go

@@ -57,6 +57,8 @@ func (manager *WebRTCManagerCtx) Start() {
 	videoIDs := manager.capture.VideoIDs()
 	manager.videoTracks = map[string]*webrtc.TrackLocalStaticSample{}
 	for _, videoID := range videoIDs {
+		videoID := videoID
+
 		video, ok := manager.capture.Video(videoID)
 		if !ok {
 			manager.logger.Warn().Str("videoID", videoID).Msg("video stream not found, skipping")
@@ -65,12 +67,12 @@ func (manager *WebRTCManagerCtx) Start() {
 
 		track, err := webrtc.NewTrackLocalStaticSample(video.Codec().Capability, "video", "stream")
 		if err != nil {
-			manager.logger.Panic().Err(err).Msgf("unable to create video (%s) track", videoID)
+			manager.logger.Panic().Err(err).Str("videoID", videoID).Msg("unable to create video track")
 		}
 	
 		video.OnSample(func(sample types.Sample) {
 			if err := track.WriteSample(media.Sample(sample)); err != nil && err != io.ErrClosedPipe {
-				manager.logger.Warn().Err(err).Msgf("video (%s) pipeline failed to write", videoID)
+				manager.logger.Warn().Err(err).Str("videoID", videoID).Msg("vide pipeline failed to write")
 			}
 		})
 
@@ -141,16 +143,12 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session) (*webrtc.Sess
 		})
 	}
 
-	_, err = connection.AddTransceiverFromTrack(manager.audioTrack, webrtc.RtpTransceiverInit{
+	_, err = connection.AddTrack(manager.audioTrack)
-		Direction: webrtc.RTPTransceiverDirectionSendonly,
-	})
 	if err != nil {
 		return nil, err
 	}
 
-	videoTransceiver, err := connection.AddTransceiverFromTrack(manager.videoTracks[manager.defaultVideoID], webrtc.RtpTransceiverInit{
+	videoSender, err := connection.AddTrack(manager.videoTracks[manager.defaultVideoID])
-		Direction: webrtc.RTPTransceiverDirectionSendonly,
-	})
 	if err != nil {
 		return nil, err
 	}
@@ -206,13 +204,13 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session) (*webrtc.Sess
 	})
 
 	session.SetWebRTCPeer(&WebRTCPeerCtx{
-		api:               api,
+		api:            api,
-		engine:            engine,
+		engine:         engine,
-		settings:          settings,
+		settings:       settings,
-		connection:        connection,
+		connection:     connection,
-		configuration:     configuration,
+		configuration:  configuration,
-		videoTracks:       manager.videoTracks,
+		videoTracks:    manager.videoTracks,
-		videoTransceiver:  videoTransceiver,
+		videoSender:    videoSender,
 	})
 
 	return connection.LocalDescription(), nil

internal/webrtc/peer.go

@@ -7,13 +7,13 @@ import (
 )
 
 type WebRTCPeerCtx struct {
-	api               *webrtc.API
+	api            *webrtc.API
-	engine            *webrtc.MediaEngine
+	engine         *webrtc.MediaEngine
-	settings          *webrtc.SettingEngine
+	settings       *webrtc.SettingEngine
-	connection        *webrtc.PeerConnection
+	connection     *webrtc.PeerConnection
-	configuration     *webrtc.Configuration
+	configuration  *webrtc.Configuration
-	videoTracks       map[string]*webrtc.TrackLocalStaticSample
+	videoTracks    map[string]*webrtc.TrackLocalStaticSample
-	videoTransceiver  *webrtc.RTPTransceiver
+	videoSender    *webrtc.RTPSender
 }
 
 func (webrtc_peer *WebRTCPeerCtx) SignalAnswer(sdp string) error {
@@ -33,7 +33,7 @@ func (webrtc_peer *WebRTCPeerCtx) SetVideoID(videoID string) error {
 		return fmt.Errorf("videoID not found in available tracks")
 	}
 
-	return webrtc_peer.videoTransceiver.Sender().ReplaceTrack(track)
+	return webrtc_peer.videoSender.ReplaceTrack(track)
 }
 
 func (webrtc_peer *WebRTCPeerCtx) Destroy() error {

internal/websocket/handler/handler.go

@@ -59,6 +59,11 @@ func (h *MessageHandlerCtx) Message(session types.Session, raw []byte) bool {
 		err = utils.Unmarshal(payload, raw, func() error {
 			return h.signalCandidate(session, payload)
 		})
+	case event.SIGNAL_VIDEO:
+		payload := &message.SignalVideo{}
+		err = utils.Unmarshal(payload, raw, func() error {
+			return h.signalVideo(session, payload)
+		})
 
 	// Control Events
 	case event.CONTROL_RELEASE:

internal/websocket/handler/signal.go

@@ -44,3 +44,13 @@ func (h *MessageHandlerCtx) signalCandidate(session types.Session, payload *mess
 
 	return peer.SignalCandidate(*payload.ICECandidateInit)
 }
+
+func (h *MessageHandlerCtx) signalVideo(session types.Session, payload *message.SignalVideo) error {
+	peer := session.GetWebRTCPeer()
+	if peer == nil {
+		h.logger.Debug().Msg("webRTC peer does not exist")
+		return nil
+	}
+
+	return peer.SetVideoID(payload.VideoID)
+}