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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2026-06-19 19:03:00 +02:00
Bogdan Lisman a62d996927 avcodec/snowenc: fix SIGFPE in get_dc() when a block lies outside the plane
get_dc() divides the accumulated, OBMC-weighted DC by aa, the sum of the
squared OBMC weights taken over the in-plane pixels.  When an OBMC block
falls entirely outside the plane - e.g. a tiny chroma plane after mcdeint
splits a frame into fields - no pixel contributes, aa stays 0 and the
ROUNDED_DIV() divides by zero (SIGFPE).  ab is 0 in exactly the same case,
so the result degenerates to 0; return it directly.

Reproducible with the GPL mcdeint filter in slow/extra_slow mode, e.g.

    ffmpeg -f lavfi -i testsrc=s=128x2 -vf mcdeint=mode=slow -f null -

Add a self-contained lavfi-based FATE regression test for the slow mode,
which previously crashed and is therefore not covered by the existing
sample-based fast/medium tests.

Fixes trac ticket #7779.

Signed-off-by: Bogdan Lisman <bogdan@pydevsolutions.com>
2026-06-17 02:27:33 +02:00
2025-08-08 21:51:15 +00:00
2026-05-31 16:58:23 +02:00
2023-03-01 21:59:10 +01:00
2025-06-23 14:48:40 +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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