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590d169bdb48e0fc30975ef4a93c4617273314a5
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>
…
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
andqt-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.
Languages
C
90.1%
Assembly
7.9%
Makefile
1.3%
C++
0.2%
Objective-C
0.2%
Other
0.1%