From 903e499dd6f5e351f790cbd630c2f8f9fcd1896c Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Fri, 12 Jun 2020 17:27:38 +0200
Subject: [PATCH] Don't reduce video rate in large groups.

---
 group.go     |  1 -
 rtpconn.go   | 11 ++---------
 webclient.go | 30 +-----------------------------
 3 files changed, 3 insertions(+), 39 deletions(-)

diff --git a/group.go b/group.go
index 12e991e..2ab4f94 100644
--- a/group.go
+++ b/group.go
@@ -45,7 +45,6 @@ type group struct {
 	name        string
 	dead        bool
 	description *groupDescription
-	videoCount  uint32
 	locked      uint32
 
 	mu      sync.Mutex
diff --git a/rtpconn.go b/rtpconn.go
index 78e96b0..2f5acda 100644
--- a/rtpconn.go
+++ b/rtpconn.go
@@ -429,10 +429,6 @@ func newUpConn(c client, id string) (*rtpUpConnection, error) {
 
 		conn.tracks = append(conn.tracks, track)
 
-		if remote.Kind() == webrtc.RTPCodecTypeVideo {
-			atomic.AddUint32(&c.Group().videoCount, 1)
-		}
-
 		go readLoop(conn, track)
 
 		go rtcpUpListener(conn, track, receiver)
@@ -1090,7 +1086,7 @@ func handleReport(track *rtpDownTrack, report rtcp.ReceptionReport, jiffies uint
 	}
 }
 
-func updateUpTrack(track *rtpUpTrack, maxVideoRate uint64) uint64 {
+func updateUpTrack(track *rtpUpTrack) uint64 {
 	now := rtptime.Jiffies()
 
 	isvideo := track.track.Kind() == webrtc.RTPCodecTypeVideo
@@ -1099,10 +1095,7 @@ func updateUpTrack(track *rtpUpTrack, maxVideoRate uint64) uint64 {
 	rate := ^uint64(0)
 	if isvideo {
 		minrate = minVideoRate
-		rate = maxVideoRate
-		if rate < minrate {
-			rate = minrate
-		}
+		rate = ^uint64(0)
 	}
 	local := track.getLocal()
 	var maxrto uint64
diff --git a/webclient.go b/webclient.go
index 46d6bac..2300758 100644
--- a/webclient.go
+++ b/webclient.go
@@ -9,7 +9,6 @@ import (
 	"encoding/json"
 	"errors"
 	"log"
-	"math"
 	"os"
 	"strings"
 	"sync"
@@ -228,7 +227,6 @@ func addUpConn(c *webClient, id string) (*rtpUpConnection, error) {
 
 	old := c.up[id]
 	if old != nil {
-		decrementVideoTracks(c, old)
 		old.pc.Close()
 	}
 
@@ -255,8 +253,6 @@ func delUpConn(c *webClient, id string) bool {
 	delete(c.up, id)
 	c.mu.Unlock()
 
-	decrementVideoTracks(c, conn)
-
 	go func(clients []client) {
 		for _, c := range clients {
 			c.pushConn(conn.id, nil, nil, "")
@@ -267,21 +263,6 @@ func delUpConn(c *webClient, id string) bool {
 	return true
 }
 
-func decrementVideoTracks(c *webClient, conn *rtpUpConnection) {
-	conn.mu.Lock()
-	defer conn.mu.Unlock()
-	for _, track := range conn.tracks {
-		if track.track.Kind() == webrtc.RTPCodecTypeVideo {
-			count := atomic.AddUint32(&c.group.videoCount,
-				^uint32(0))
-			if count == ^uint32(0) {
-				log.Printf("Negative track count!")
-				atomic.StoreUint32(&c.group.videoCount, 0)
-			}
-		}
-	}
-}
-
 func getDownConn(c *webClient, id string) *rtpDownConnection {
 	if c.down == nil {
 		return nil
@@ -1042,21 +1023,12 @@ func handleClientMessage(c *webClient, m clientMessage) error {
 }
 
 func sendRateUpdate(c *webClient) {
-	maxVideoRate := ^uint64(0)
-	count := atomic.LoadUint32(&c.group.videoCount)
-	if count >= 3 {
-		maxVideoRate = uint64(2000000 / math.Sqrt(float64(count)))
-		if maxVideoRate < minVideoRate {
-			maxVideoRate = minVideoRate
-		}
-	}
-
 	up := getUpConns(c)
 
 	for _, u := range up {
 		tracks := u.getTracks()
 		for _, t := range tracks {
-			rate := updateUpTrack(t, maxVideoRate)
+			rate := updateUpTrack(t)
 			if !t.hasRtcpFb("goog-remb", "") {
 				continue
 			}