Bogdan Lisman 223764a43e avcodec/snowenc: fix out-of-bounds memcpy in get_block_rd() for narrow planes
For an edge block, get_block_rd() copies the full-OBMC-weight central
region directly from cur[] into the reconstruction.  It moved one
boundary to block_w/block_h but overwrote the in-plane clip (x0/x1/y0/y1
computed earlier from the plane size) instead of intersecting with it.
When a plane is narrower than block_w - e.g. a tiny field/chroma plane
produced by the mcdeint filter - the right-edge case left x0 = block_w
while x1 stayed clipped to w - sx < block_w, so x1 - x0 became negative
and was passed to memcpy() as a huge size_t, crashing with SIGSEGV.

Intersect the moved boundaries with the existing clip so the copy region
stays inside the plane and the memcpy length can never be negative.

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

    ffmpeg -f lavfi -i testsrc=s=5x32 -vf mcdeint=mode=slow -f null -

This is a separate crash from the get_dc() SIGFPE (ticket #7779) reached
through the same iterative_me() path.  Add a lavfi-based FATE regression
test.

Signed-off-by: Bogdan Lisman <bogdan@pydevsolutions.com>
(cherry picked from commit 1168447626)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2026-06-15 23:57:25 +02:00
2026-05-03 19:42:27 +02:00
2026-05-04 00:07:35 +02:00
2026-01-12 17:28:41 +01:00
2025-08-08 21:51:15 +00:00
2026-05-03 19:42:27 +02:00
2026-02-22 04:39:22 +00:00
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2025-08-03 13:48:47 +02:00
2025-05-07 15:35:47 +02:00
2026-05-03 19:42:27 +02:00

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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