Michael Niedermayer 9ddab572c0 avcodec/h264_mb: Fix tmp_cr for arm
When decoding a bitstream with weighted-bipred enabled,
the results on ARM and x86 platforms may differ.

The reason for the inconsistency is that the value of
STRIDE_ALIGN differs between platforms. And STRIDE_ALIGN
is set to the buffer stride of temporary buffers for U
and V components in mc_part_weighted.

If the buffer stride is 32 or 64 (as on x86 platforms),
the U and V pixels can be interleaved row by row without
overlapping, resulting in correct output.
However, on ARM platforms where the stride is 16,
the V component did overwrite part of the U component's pixels,
leading to incorrect predicted pixels.

The bug can be reproduced by the following bitstream.

https://trac.ffmpeg.org/attachment/ticket/11357/inter_weighted_bipred2.264

Fixes: ticket 11357
Commit-msg-mostly-by: Bin Peng <pengbin@visionular.com>
Reviewed-by: Bin Peng <pengbin@visionular.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 74fd2c3ddb)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2025-06-11 17:29:47 +02:00
2025-06-11 17:29:41 +02:00
2022-03-17 18:35:41 -03:00
2024-07-15 01:59:37 +02:00
2025-03-02 16:29:39 +01:00
2023-03-01 21:59:10 +01:00
2019-12-28 11:20:48 +01:00
2024-08-08 15:26:52 +02:00
2025-03-02 16:29:39 +01:00

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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