Fixing offset calculation (#723)

milos-lk · web-flow · commit 25ae5bc635e6 · 2025-08-25T19:45:01.000+02:00
Sender reports shouldn't overwrite the desired offset but update it.
Also signal the correct diff in onSR callbacks,
diff --git a/pkg/synchronizer/track.go b/pkg/synchronizer/track.go
@@ -164,14 +164,14 @@ func (t *TrackSynchronizer) onSenderReport(pkt *rtcp.SenderReport) {
 
 	offset := mediatransportutil.NtpTime(pkt.NTPTime).Time().Sub(t.startTime.Add(pts))
 	if t.onSR != nil {
-		t.onSR(offset - t.desiredPTSOffset)
+		t.onSR(offset)
 	}
 
 	if !t.acceptable(offset) {
 		return
 	}
 
-	t.desiredPTSOffset = offset
+	t.desiredPTSOffset += offset
 	t.lastSR = pkt.RTPTime
 }
 

Original file line number	Diff line number	Diff line change
`@@ -164,14 +164,14 @@ func (t TrackSynchronizer) onSenderReport(pkt rtcp.SenderReport) {`
`164`	`164`
`165`	`165`	`offset := mediatransportutil.NtpTime(pkt.NTPTime).Time().Sub(t.startTime.Add(pts))`
`166`	`166`	`if t.onSR != nil {`
`167`		`- t.onSR(offset - t.desiredPTSOffset)`
	`167`	`+ t.onSR(offset)`
`168`	`168`	`}`
`169`	`169`
`170`	`170`	`if !t.acceptable(offset) {`
`171`	`171`	`return`
`172`	`172`	`}`
`173`	`173`
`174`		`- t.desiredPTSOffset = offset`
	`174`	`+ t.desiredPTSOffset += offset`
`175`	`175`	`t.lastSR = pkt.RTPTime`
`176`	`176`	`}`
`177`	`177`