停止Live555重用会话

Question

我正在使用Live555从远程连接上的IP网络摄像头获取数据。有时，流会有短暂的中断(这可能是网络服务质量问题)，然而，每次发生这种情况时，live555都会死亡，而不是成功地重新启动连接。调试输出如下所示：

Closing session, because we stopped receiving packets.itrate=N/A speed=1.37x
Created new TCP socket 3 for connection
Connecting to 10.8.1.14, port 10111 on socket 3...
...remote connection opened
Sending request: PLAY rtsp://mycamera.test/live/ch0/ RTSP/1.0
CSeq: 6
User-Agent: /bin/openRTSP (LIVE555 Streaming Media v2017.07.18)
Session: 1487641045855494467
Range: npt=0.000-

Received 199 new bytes of response data.
Received a complete PLAY response:
RTSP/1.0 500 Internal Server Error
Server: DSS/6.0.3 (Build/526.3; Platform/Linux; Release/Darwin Streaming Server; State/Development; )
Cseq: 6
Session: 1487641045855494467
Connection: Close

Failed to start playing session: 500 Internal Server Error
Created new TCP socket 3 for connection
Connecting to 10.8.1.14, port 10111 on socket 3...
...remote connection opened
Sending request: TEARDOWN rtsp://mycamera.test/live/ch0/ RTSP/1.0
CSeq: 7
User-Agent: /bin/openRTSP (LIVE555 Streaming Media v2017.07.18)
Session: 1487641045855494467

Received 180 new bytes of response data.
Received a complete TEARDOWN response:
RTSP/1.0 200 OK
Server: DSS/6.0.3 (Build/526.3; Platform/Linux; Release/Darwin Streaming Server; State/Development; )
Cseq: 7
Session: 1487641045855494467
Connection: Close

live555退出的原因似乎是因为当尝试重新启动现有会话的流时，摄像头会抛出500错误。既然启动一个新的会话可以工作，有没有办法告诉live555放弃现有的会话并重新开始，而不是放弃？我确实有一个cron作业，它可以检测live555何时停止并重新启动它，但当我这样做时，会有敲门问题，所以如果我能说服live555来补偿相机固件中的错误，它会更干净。

我很乐意为live555代码打补丁，并在必要时进行重建！

Answer 1

如果您查看playCommon.cpp的代码，您可以看到

void sessionAfterPlaying(void* /*clientData*/) {
  if (!playContinuously) {
    shutdown(0);
  } else {
    // We've been asked to play the stream(s) over again.
    // First, reset state from the current session:
    if (env != NULL) {
      env->taskScheduler().unscheduleDelayedTask(periodicFileOutputTask);
      env->taskScheduler().unscheduleDelayedTask(sessionTimerTask);
      env->taskScheduler().unscheduleDelayedTask(arrivalCheckTimerTask);
      env->taskScheduler().unscheduleDelayedTask(interPacketGapCheckTimerTask);
      env->taskScheduler().unscheduleDelayedTask(qosMeasurementTimerTask);
    }
    totNumPacketsReceived = ~0;

    startPlayingSession(session, initialSeekTime, endTime, scale, continueAfterPLAY);
  }
}

正如您在日志中看到的，它会发送一个播放，并且不会重新启动会话。为了改变这种行为，你需要修改openRTSP的代码。