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Andreas Rheinhardt 590d169bdb avcodec/decode: Reset MMX state for receive_frame decoders, too
FFmpeg's assembly code currently does not abide by the
plattform-specific ABIs wrt its handling of the X86 MMX flag:
Resetting the MMX state is deferred to avoid doing it multiple times
instead of ensuring that the CPU is in floating point state
upon return from any function.

Furthermore, resetting said state is sometimes done generically,
namely for all the decoders using the ordinary decode callback;
yet this is not done for the decoders using the receive_frame API.

This led to problems when MJPEG (and the MJPEG-based decoders)
were switched to the receive_frame API in commit
e9a2a87773, because ff_mjpeg_decode_sos()
only resets the MMX state on success, not on failure.
Such issues are probably still possible with SMVJPEG, which still
uses the receive_frame API. See issue #10210.

This commit therefore also resets the MMX state for
the receive_frame API to avoid any more surprises of this sort.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2023-03-18 05:10:24 +01:00
2022-03-17 18:35:41 -03:00
2023-03-01 21:59:10 +01:00
2019-12-28 11:20:48 +01:00
2022-07-13 00:31:42 +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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