add passive estimator & REMB back. (#35)

internal/config/webrtc.go

@@ -28,6 +28,7 @@ type WebRTC struct {
 	IpRetrievalUrl string
 
 	EstimatorEnabled        bool
+	EstimatorPassive        bool
 	EstimatorInitialBitrate int
 }
 
@@ -79,6 +80,11 @@ func (WebRTC) Init(cmd *cobra.Command) error {
 		return err
 	}
 
+	cmd.PersistentFlags().Bool("webrtc.estimator.passive", false, "passive estimator mode, when it does not switch pipelines, only estimates")
+	if err := viper.BindPFlag("webrtc.estimator.passive", cmd.PersistentFlags().Lookup("webrtc.estimator.passive")); err != nil {
+		return err
+	}
+
 	cmd.PersistentFlags().Int("webrtc.estimator.initial_bitrate", 1_000_000, "initial bitrate for the bandwidth estimator")
 	if err := viper.BindPFlag("webrtc.estimator.initial_bitrate", cmd.PersistentFlags().Lookup("webrtc.estimator.initial_bitrate")); err != nil {
 		return err
@@ -154,5 +160,6 @@ func (s *WebRTC) Set() {
 	// bandwidth estimator
 
 	s.EstimatorEnabled = viper.GetBool("webrtc.estimator.enabled")
+	s.EstimatorPassive = viper.GetBool("webrtc.estimator.passive")
 	s.EstimatorInitialBitrate = viper.GetInt("webrtc.estimator.initial_bitrate")
 }

internal/webrtc/manager.go

@@ -316,8 +316,8 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, bitrate int,
 		return nil, err
 	}
 
-	// if estimator is disabled, disable video auto
-	if !manager.config.EstimatorEnabled {
+	// if estimator is disabled, or in passive mode, disable video auto bitrate
+	if !manager.config.EstimatorEnabled || manager.config.EstimatorPassive {
 		videoAuto = false
 	}
 
@@ -338,7 +338,7 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, bitrate int,
 	changeVideoFromBitrate := func(peerBitrate int) {
 		// when switching from manual to auto bitrate estimation, in case the estimator is
 		// idle (lastBitrate > maxBitrate), we want to go back to the previous estimated bitrate
-		if peerBitrate == 0 && estimator != nil {
+		if peerBitrate == 0 && estimator != nil && !manager.config.EstimatorPassive {
 			peerBitrate = estimator.GetTargetBitrate()
 			manager.logger.Debug().
 				Int("peer_bitrate", peerBitrate).
@@ -423,7 +423,7 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, bitrate int,
 
 			for range ticker.C {
 				targetBitrate := estimator.GetTargetBitrate()
-				manager.metrics.SetReceiverEstimatedMaximumBitrate(session, float64(targetBitrate))
+				manager.metrics.SetReceiverEstimatedTargetBitrate(session, float64(targetBitrate))
 
 				if connection.ConnectionState() == webrtc.PeerConnectionStateClosed {
 					break
@@ -431,8 +431,10 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, bitrate int,
 				if !videoTrack.VideoAuto() {
 					continue
 				}
+				if !manager.config.EstimatorPassive {
 					changeVideoFromBitrate(targetBitrate)
 				}
+			}
 		}()
 	}
 
@@ -457,10 +459,11 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, bitrate int,
 		},
 		iceTrickle: manager.config.ICETrickle,
 		setVideoAuto: func(videoAuto bool) {
-			if manager.config.EstimatorEnabled {
+			// if estimator is enabled and not in passive mode, enable video auto bitrate
+			if manager.config.EstimatorEnabled && !manager.config.EstimatorPassive {
 				videoTrack.SetVideoAuto(videoAuto)
 			} else {
-				logger.Warn().Msg("estimator is disabled, cannot change video auto")
+				logger.Warn().Msg("estimator is disabled or in passive mode, cannot change video auto")
 				videoTrack.SetVideoAuto(false) // ensure video auto is disabled
 			}
 		},
@@ -666,7 +669,11 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, bitrate int,
 			}
 
 			for _, p := range packets {
-				if rtcpPacket, ok := p.(*rtcp.ReceiverReport); ok {
+				switch rtcpPacket := p.(type) {
+				case *rtcp.ReceiverEstimatedMaximumBitrate: // TODO: Deprecated.
+					manager.metrics.SetReceiverEstimatedMaximumBitrate(session, rtcpPacket.Bitrate)
+
+				case *rtcp.ReceiverReport:
 					l := len(rtcpPacket.Reports)
 					if l > 0 {
 						// use only last report

internal/webrtc/metrics.go

@@ -27,6 +27,7 @@ type metrics struct {
 	videoIdsMu *sync.Mutex
 
 	receiverEstimatedMaximumBitrate prometheus.Gauge
+	receiverEstimatedTargetBitrate  prometheus.Gauge
 
 	receiverReportDelay     prometheus.Gauge
 	receiverReportJitter    prometheus.Gauge
@@ -144,6 +145,15 @@ func (m *metricsCtx) getBySession(session types.Session) metrics {
 				"session_id": session.ID(),
 			},
 		}),
+		receiverEstimatedTargetBitrate: promauto.NewGauge(prometheus.GaugeOpts{
+			Name:      "receiver_estimated_target_bitrate",
+			Namespace: "neko",
+			Subsystem: "webrtc",
+			Help:      "Receiver Estimated Target Bitrate using Google's congestion control.",
+			ConstLabels: map[string]string{
+				"session_id": session.ID(),
+			},
+		}),
 
 		receiverReportDelay: promauto.NewGauge(prometheus.GaugeOpts{
 			Name:      "receiver_report_delay",
@@ -327,10 +337,16 @@ func (m *metricsCtx) SetVideoID(session types.Session, videoId string) {
 	}
 }
 
-func (m *metricsCtx) SetReceiverEstimatedMaximumBitrate(session types.Session, bitrate float64) {
+func (m *metricsCtx) SetReceiverEstimatedMaximumBitrate(session types.Session, bitrate float32) {
 	met := m.getBySession(session)
 
-	met.receiverEstimatedMaximumBitrate.Set(bitrate)
+	met.receiverEstimatedMaximumBitrate.Set(float64(bitrate))
+}
+
+func (m *metricsCtx) SetReceiverEstimatedTargetBitrate(session types.Session, bitrate float64) {
+	met := m.getBySession(session)
+
+	met.receiverEstimatedTargetBitrate.Set(bitrate)
 }
 
 func (m *metricsCtx) SetReceiverReport(session types.Session, report rtcp.ReceptionReport) {

pkg/types/codec/codecs.go

@@ -8,7 +8,7 @@ import (
 
 var RTCPFeedback = []webrtc.RTCPFeedback{
 	{Type: webrtc.TypeRTCPFBTransportCC, Parameter: ""},
-	{Type: webrtc.TypeRTCPFBGoogREMB, Parameter: ""},
+	{Type: webrtc.TypeRTCPFBGoogREMB, Parameter: ""}, // TODO: Deprecated.
 
 	// https://www.iana.org/assignments/sdp-parameters/sdp-parameters.xhtml#sdp-parameters-19
 	{Type: webrtc.TypeRTCPFBCCM, Parameter: "fir"},