Don't report drift that's not applied (#768)

The initial idea behind invoking callback regardless of whether the drift was applied or not was logging. Now that we log not acceptable and high drift values - there is no reason to invoke the callback for the drift that's not applied. Makes data cleaner and prevents acting on something that was essentially skipped.

Author: milos-lk

pkg/synchronizer/track.go

@@ -538,9 +538,6 @@ func (t *TrackSynchronizer) onSenderReportWithoutRebase(pkt *rtcp.SenderReport)
 	}
 
 	drift := mediatransportutil.NtpTime(pkt.NTPTime).Time().Sub(t.startTime.Add(pts))
-	if t.onSR != nil {
-		t.onSR(drift)
-	}
 	if drift > cHighDriftLoggingThreshold || drift < -cHighDriftLoggingThreshold {
 		t.logger.Infow(
 			"high drift sender report",
@@ -560,6 +557,10 @@ func (t *TrackSynchronizer) onSenderReportWithoutRebase(pkt *rtcp.SenderReport)
 		return
 	}
 
+	if t.onSR != nil {
+		t.onSR(drift)
+	}
+
 	t.desiredPTSOffset = t.basePTSOffset + drift
 	t.lastSR = augmented
 }
@@ -619,9 +620,6 @@ func (t *TrackSynchronizer) onSenderReportWithRebase(pkt *rtcp.SenderReport) {
 
 	// drift is based on local clock
 	drift := time.Unix(0, augmented.receivedAtAdjusted).Sub(t.startTime.Add(ptsSR))
-	if t.onSR != nil {
-		t.onSR(drift)
-	}
 	if drift > cHighDriftLoggingThreshold || drift < -cHighDriftLoggingThreshold {
 		t.logger.Infow(
 			"high drift sender report",
@@ -644,6 +642,10 @@ func (t *TrackSynchronizer) onSenderReportWithRebase(pkt *rtcp.SenderReport) {
 		return
 	}
 
+	if t.onSR != nil {
+		t.onSR(drift)
+	}
+
 	t.desiredPTSOffset = t.basePTSOffset + drift
 	t.lastSR = augmented
 }