RTSP video stream freezes after 120 s on VLC 3.0.4 Vetinari

[kprav33n]

I'm trying to play a RTSP video stream from Cisco Video Surveillance Manager using VLC 3.0.4. The stream starts playing fine. However, after 120 second, the stream just freezes. Here are some details about the situation:

1. Stream is received over TCP (Transport: RTP/AVP/TCP;unicast;interleaved=0-1)
2. Server's timeout is 120s. (Session: 1337177747;timeout=120)
3. Server supports GET_PARAMETER (Public: DESCRIBE, SETUP, PLAY, PAUSE, TEARDOWN, PAUSE, GET_PARAMETER, SET_PARAMETER, ANNOUNCE)
4. VLC sends RTSP GET_PARAMETER at about 118s after the stream started, and the video freezes immediately after that.
5. Using Wireshark shows that the stream is still being received on the TCP socket after the video freezes. But, VLC is not updating the view.

This doesn't look like a macOS only problem. I tried the same on Debian Stretch 9.5/VLC 3.0.3. The result is the same. The stream freezes close to 120s which is the RTSP server session timeout.

I tried the same stream with VLC 2.2.8, and it plays for longer duration without any interruption. I also tried the same stream with python-vlc, and VLCKit. The stream freezes after 120s with VLC 3.0.4. The same Python script works fine when using with VLC 2.2.8.

FWIW, I tried `--rtsp-kasenna` and `--rtsp-wmserver` command line options, and it doesn't seem to help. I'm not quite sure if the problem is with VLC, or with live555. The working case uses LIVE555 Streaming Media v2016.02.22, while the broken case uses LIVE555 Streaming Media v2016.11.28.

Here is the output of VLC with `--verbose 4 --rtsp-tcp` option: https://gist.github.com/kprav33n/020ac4 ... 03feaa3e7d

Thanks for looking at this, and I highly appreciate any suggestions on what to try next.

[kprav33n]

I examined VLC source code and figured out that the fix for this is available in the latest nightlies. For future reference, let me give some pointers here.

Apparently, sending GET_PARAMETER while using TCP streaming is not correct. There was a fix for this to VLC source code on Aug 21 2018, that is not yet available in a stable release. This will be part of 3.0.5. I tried the nightly build (Oct 22 2018), and it seems to work fine without freezing up after 120 s.

Here is the change that was made in TimeoutPrevention() of live555.cpp:

Code: Select all

if( var_GetBool( p_demux, "rtsp-tcp" ) ) return;

Commit that fixed this: https://github.com/videolan/vlc/commit/ ... 1cd08db856
Mail thread on live555-devel: https://www.mail-archive.com/live-devel ... 03093.html

Also, for those who are interested in the Cisco Video Surveillance Manager (VSM) client for macOS, here is the Python utility that I developed:

PyPI: https://pypi.org/project/vsmstreamer/
Github: https://github.com/kprav33n/vsmstreamer

Thanks to anyone who spent time on this thread.