From fcf68228334bad5e03da2909b9aef46fc6530567 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miroslav=20=C5=A0ediv=C3=BD?= <sedivy.miro@gmail.com>
Date: Mon, 17 Apr 2023 01:10:20 +0200
Subject: [PATCH] move estimator to peer.

---
 internal/webrtc/manager.go | 33 +++++-------------------------
 internal/webrtc/peer.go    | 41 ++++++++++++++++++++++++++++++++++----
 2 files changed, 42 insertions(+), 32 deletions(-)

diff --git a/internal/webrtc/manager.go b/internal/webrtc/manager.go
index 41311617..74a4b2af 100644
--- a/internal/webrtc/manager.go
+++ b/internal/webrtc/manager.go
@@ -369,7 +369,8 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, bitrate int,
 		dataChannel: dataChannel,
 		rtcpChannel: videoRtcp,
 		// config
-		iceTrickle: manager.config.ICETrickle,
+		iceTrickle:       manager.config.ICETrickle,
+		estimatorPassive: manager.config.EstimatorPassive,
 	}
 
 	logger.Info().
@@ -381,33 +382,6 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, bitrate int,
 		return nil, err
 	}
 
-	// if estimator is enabled, use it to change video stream
-	if estimator != nil {
-		go func() {
-			// use a ticker to get current client target bitrate
-			ticker := time.NewTicker(bitrateCheckInterval)
-			defer ticker.Stop()
-
-			for range ticker.C {
-				targetBitrate := estimator.GetTargetBitrate()
-				metrics.SetReceiverEstimatedTargetBitrate(float64(targetBitrate))
-
-				if connection.ConnectionState() == webrtc.PeerConnectionStateClosed {
-					break
-				}
-				if !videoTrack.VideoAuto() {
-					continue
-				}
-				if !manager.config.EstimatorPassive {
-					err := peer.SetVideoBitrate(targetBitrate)
-					if err != nil {
-						logger.Warn().Err(err).Msg("failed to set video bitrate")
-					}
-				}
-			}
-		}()
-	}
-
 	connection.OnTrack(func(track *webrtc.TrackRemote, receiver *webrtc.RTPReceiver) {
 		logger := logger.With().
 			Str("kind", track.Kind().String()).
@@ -602,6 +576,9 @@ func (manager *WebRTCManagerCtx) CreatePeer(session types.Session, bitrate int,
 	go metrics.rtcpReceiver(videoRtcp)
 	go metrics.connectionStats(connection)
 
+	// start estimator reader
+	go peer.estimatorReader()
+
 	return offer, nil
 }
 
diff --git a/internal/webrtc/peer.go b/internal/webrtc/peer.go
index 16381e12..ddadb036 100644
--- a/internal/webrtc/peer.go
+++ b/internal/webrtc/peer.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"sync"
+	"time"
 
 	"github.com/pion/interceptor/pkg/cc"
 	"github.com/pion/rtcp"
@@ -29,7 +30,8 @@ type WebRTCPeerCtx struct {
 	dataChannel *webrtc.DataChannel
 	rtcpChannel chan []rtcp.Packet
 	// config
-	iceTrickle bool
+	iceTrickle       bool
+	estimatorPassive bool
 }
 
 //
@@ -106,6 +108,37 @@ func (peer *WebRTCPeerCtx) Destroy() {
 	}
 }
 
+func (peer *WebRTCPeerCtx) estimatorReader() {
+	// if estimator is disabled, do nothing
+	if peer.estimator == nil {
+		return
+	}
+
+	// use a ticker to get current client target bitrate
+	ticker := time.NewTicker(bitrateCheckInterval)
+	defer ticker.Stop()
+
+	for range ticker.C {
+		targetBitrate := peer.estimator.GetTargetBitrate()
+		peer.metrics.SetReceiverEstimatedTargetBitrate(float64(targetBitrate))
+
+		if peer.connection.ConnectionState() == webrtc.PeerConnectionStateClosed {
+			break
+		}
+
+		if !peer.videoTrack.VideoAuto() {
+			continue
+		}
+
+		if !peer.estimatorPassive {
+			err := peer.SetVideoBitrate(targetBitrate)
+			if err != nil {
+				peer.logger.Warn().Err(err).Msg("failed to set video bitrate")
+			}
+		}
+	}
+}
+
 //
 // video
 //
@@ -116,7 +149,7 @@ func (peer *WebRTCPeerCtx) SetVideoBitrate(peerBitrate int) error {
 
 	// 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 && peer.estimator != nil {
+	if peerBitrate == 0 && peer.estimator != nil && !peer.estimatorPassive {
 		peerBitrate = peer.estimator.GetTargetBitrate()
 		peer.logger.Debug().
 			Int("peer_bitrate", peerBitrate).
@@ -205,8 +238,8 @@ func (peer *WebRTCPeerCtx) SetPaused(isPaused bool) error {
 }
 
 func (peer *WebRTCPeerCtx) SetVideoAuto(videoAuto bool) {
-	// if estimator is enabled, enable video auto bitrate
-	if peer.estimator != nil {
+	// if estimator is enabled and is not passive, enable video auto bitrate
+	if peer.estimator != nil && !peer.estimatorPassive {
 		peer.videoTrack.SetVideoAuto(videoAuto)
 	} else {
 		peer.logger.Warn().Msg("estimator is disabled or in passive mode, cannot change video auto")