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Issue created by Administrator@rootContributor4 of 6 checklist items completed4/6 checklist items

The timeout setting on av.open() doesn't work as expected (for RTSP streams)

Created by: CarlosRDomin

Overview

When I connect to my rtsp camera with a given timeout (e.g. 3s), the call to av.open() blocks indefinitely if the camera accepts the connection but doesn't start streaming

Expected behavior

After the timeout expires (e.g. 3s) the function call should return with an error/exception

Actual behavior

The call to av.open() hangs indefinitely and I have to kill -s 9 python to stop the process.

Investigation

My RTSP camera only accepts 3 simultaneous clients receiving the stream. If (by accident) a 4th client attempts to connect, it will successfully communicate with the camera, but no stream is sent, which (after adding some logs on av/container/core.pyx) causes line 234 (self.set_timeout(None)) to clear the timeout and therefore the call to av.open hangs forever.
By commenting out line 234 (not sure why the timeout is cleared anyway or where the execution hangs after line 234 to cause that infinite block), av.open successfully returns after the specified timeout if it wasn't able to open. In my case, it actually outputs some nice error messages:

Could not find codec parameters for stream 0 (Video: h264, none): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options

Versions

  • OS: Ubuntu 18.04 (on docker image)
  • PyAV runtime:
PyAV v7.0.0.dev0
git origin: git@github.com:mikeboers/PyAV
git commit: v6.2.0-117-g5d192a1
library configuration: --prefix=/usr --extra-version=0ubuntu0.18.04.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
library license: GPL version 2 or later
libavcodec     57.107.100
libavdevice    57. 10.100
libavfilter     6.107.100
libavformat    57. 83.100
libavutil      55. 78.100
libswresample   2.  9.100
libswscale      4.  8.100
  • PyAV build:
PyAV: 7.0.0.dev0 v6.2.0-117-g5d192a1
Python: 3.6.7 (default, Oct 22 2018, 11:32:17) \n[GCC 8.2.0]
platform: Linux-4.9.184-linuxkit-x86_64-with-Ubuntu-18.04-bionic
extension_extra:
        include_dirs: [b'include', b'/usr/include/x86_64-linux-gnu']
        libraries: [b'avformat', b'avcodec', b'avdevice', b'avutil', b'avfilter', b'swscale', b'swresample']
        library_dirs: []
        define_macros: []
        runtime_library_dirs: []
config_macros:
        PYAV_COMMIT_STR="v6.2.0-117-g5d192a1"
        PYAV_VERSION=7.0.0.dev0
        PYAV_VERSION_STR="7.0.0.dev0"
  • FFmpeg:
bash: ffmpeg: command not found

Research

I have done the following:

Additional context

See above as to when the timeout doesn't work as expected (when the camera reaches the maximum number of simultaneous streams)