Start connection stats only after bind (#480)

pkg/sfu/buffer/buffer.go

@@ -268,7 +268,7 @@ func (b *Buffer) Close() error {
 			b.audioPool.Put(b.bucket.src)
 		}
 		b.closed.Store(true)
-		b.onClose()
+		b.callbacksQueue.Enqueue(b.onClose)
 		b.callbacksQueue.Stop()
 	})
 	return nil

pkg/sfu/downtrack.go

@@ -194,7 +194,6 @@ func NewDownTrack(
 			})
 		}
 	})
-	d.connectionStats.Start()
 
 	return d, nil
 }
@@ -212,6 +211,8 @@ func (d *DownTrack) Bind(t webrtc.TrackLocalContext) (webrtc.RTPCodecParameters,
 		return webrtc.RTPCodecParameters{}, webrtc.ErrUnsupportedCodec
 	}
 
+	d.callbacksQueue.Start()
+
 	d.ssrc = uint32(t.SSRC())
 	d.payloadType = uint8(codec.PayloadType)
 	d.writeStream = t.WriteStream()
@@ -231,7 +232,7 @@ func (d *DownTrack) Bind(t webrtc.TrackLocalContext) (webrtc.RTPCodecParameters,
 
 	go d.requestFirstKeyframe()
 
-	d.callbacksQueue.Start()
+	d.connectionStats.Start()
 
 	return codec, nil
 }