Niklas Haas 133a0bcb13 fftools/ffmpeg_sched: prevent demuxers from getting stuck
When the furthest-behind stream is being fed by a demuxer that is also
feeding packets to a choked filter graph, we need to unchoke that filter
graph to prevent the demuxer from getting stuck trying to write packets to
the choked filter graph.

This situation can also apply recursively - if the demuxer is also writing
to a filtergraph that is also reading from a choked demuxer, there is a
similar deadlock.

Solve all such deadlocks by just brute-force recursively unchoking all
nodes that can somehow prevent this demuxer from writing packets. This
should normally not result in any change in behavior, unless audio/video
streams are badly desynchronized, in which case it may result in extra
memory usage from the too-far-ahead stream buffering packets inside the
muxer. (But this is, of course, preferable to a deadlock)

Fixes: https://code.ffmpeg.org/FFmpeg/FFmpeg/issues/20611
2025-11-10 09:55:40 +00:00
2025-08-08 21:51:15 +00:00
2025-06-23 14:48:40 +02:00
2025-08-03 13:48:47 +02:00
2025-05-07 15:35:47 +02:00
2025-08-14 08:42:29 -04:00

FFmpeg README

FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.

Libraries

  • libavcodec provides implementation of a wider range of codecs.
  • libavformat implements streaming protocols, container formats and basic I/O access.
  • libavutil includes hashers, decompressors and miscellaneous utility functions.
  • libavfilter provides means to alter decoded audio and video through a directed graph of connected filters.
  • libavdevice provides an abstraction to access capture and playback devices.
  • libswresample implements audio mixing and resampling routines.
  • libswscale implements color conversion and scaling routines.

Tools

  • ffmpeg is a command line toolbox to manipulate, convert and stream multimedia content.
  • ffplay is a minimalistic multimedia player.
  • ffprobe is a simple analysis tool to inspect multimedia content.
  • Additional small tools such as aviocat, ismindex and qt-faststart.

Documentation

The offline documentation is available in the doc/ directory.

The online documentation is available in the main website and in the wiki.

Examples

Coding examples are available in the doc/examples directory.

License

FFmpeg codebase is mainly LGPL-licensed with optional components licensed under GPL. Please refer to the LICENSE file for detailed information.

Contributing

Patches should be submitted to the ffmpeg-devel mailing list using git format-patch or git send-email. Github pull requests should be avoided because they are not part of our review process and will be ignored.

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