停止Live555重用會話

Question

我正在使用Live555從遠程連接上的IP網絡攝像頭提取數據。 流有時會短暫中斷（這可能是網絡QOS問題），但是live555每次發生這種情況都會死掉，而不是成功重新啟動連接。 調試輸出如下所示：

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

似乎live555失敗的原因是，當嘗試為現有會話重新啟動流時，相機拋出500錯誤。 由於開始新的會話有效，是否有任何方法可以告訴live555放棄現有會話並重新開始，而不僅僅是放棄？ 我確實有一項cron作業，可以檢測到live555何時停止並重新啟動，但是這樣做時會出現問題，因此，如果我能說服live555來彌補相機固件中的錯誤，它將變得更加干凈。

我很樂意修補live555代碼並在必要時進行重建！

Answer 1

如果查看playCommon.cpp的代碼，您會看到

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);
  }
}

如您在日志中所看到的，它發送PLAY，並且不會重新啟動會話。 為了更改此行為，您需要修改openRTSP的代碼。