无法在 VideoRenderer 中加载远程视频轨道，调用 onAddStream() 时

Question

我正在android中实现webrtc。在 peerConnection 对象中设置 remoteDescription 后，我无法加载远程视频流。我正在获取远程音频、视频轨道，当 onAddStream() 调用时（org.webrtc.VideoTrack@37471a54）。但无法在 Videorender 中加载它。

@Override
        public void onAddStream(final MediaStream stream) {
            Log.d("checklog","onaddstream"+stream.audioTracks.get(0)+stream.videoTracks.get(0));
            executor.execute(new Runnable() {
                @Override
                public void run() {
                    if (peerConnection == null ) {
                        return;
                    }
                    if (stream.audioTracks.size() > 1 || stream.videoTracks.size() > 1) {
                        Log.d("onAddstreamerror","Weird-looking stream: " + stream);
                        return;
                    }
                    if (stream.videoTracks.size() == 1) {
                        remoteVideoTrack = stream.videoTracks.get(0);
                        remoteVideoTrack.setEnabled(true);
                        remoteVideoTrack.addRenderer(new VideoRenderer(remoteRender));
                    }
                }
            });
        }