framerate not being set in version 10.0.0 for valid video source

Created by: Kieran-Bacon

Overview

The stream.codec_context.framerate is being set to None when reading a h264 file from disk in 10.0.0 despite previous versions being able to read this information.

The same video correctly gives the right framerate when av is downgraded to version 9.2.0 => Fraction(12,1)

Expected behavior

The framerate is read and set correctly

Actual behavior

framerate not being read

Investigation

My application has been running for a long time perfectly fine, doing some tests locally and noticed that the my process was raising errors on each file.

I identified that the framerate wasn't being read in the context that I needed, and I isolated the AV code in the example below.

I downgraded to a the version of av to the production version and it resolved the issue.

Reproduction

pip install av

python
video = av.open(path)
float(video.streams.videos[0].codec_context.framerate)

Works in 9.2.0 - 10.0.0 raises cannot float None value

Versions

OS: python:3.9-slim-buster docker image
PyAV runtime: 10.0.0

PyAV v10.0.0
library configuration: --disable-static --enable-shared --libdir=/tmp/vendor/lib --prefix=/tmp/vendor --disable-alsa --disable-doc --disable-mediafoundation --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-lzma --enable-version3 --enable-zlib
library license: GPL version 3 or later
libavcodec     59. 37.100
libavdevice    59.  7.100
libavfilter     8. 44.100
libavformat    59. 27.100
libavutil      57. 28.100
libswresample   4.  7.100
libswscale      6.  7.100

FFmpeg:

.ffmpeg version 4.1.9-0+deb10u1 Copyright (c) 2000-2022 the FFmpeg developers
built with gcc 8 (Debian 8.3.0-6)
configuration: --prefix=/usr --extra-version=0+deb10u1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
libavutil      56. 22.100 / 56. 22.100
libavcodec     58. 35.100 / 58. 35.100
libavformat    58. 20.100 / 58. 20.100
libavdevice    58.  5.100 / 58.  5.100
libavfilter     7. 40.101 /  7. 40.101
libavresample   4.  0.  0 /  4.  0.  0
libswscale      5.  3.100 /  5.  3.100
libswresample   3.  3.100 /  3.  3.100
libpostproc    55.  3.100 / 55.  3.100

Research

I have done the following:

Checked the PyAV documentation
Searched on Google
Searched on Stack Overflow
Looked through old GitHub issues
Asked on PyAV Gitter
... and waited 72 hours for a response.

Additional context

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