92d0a598ad
ff_slice_thread_init() uses a static variable to hold a function pointer, although the value of said pointer needn't be saved between different runs of this function at all. The reason for this being so is probably that said pointer points to a static function (if used); but storage class specifiers like "static" are not part of the type of an object and so including it in the pointer declaration is wrong (anyway, "static" means different things in both contexts: for the function declaration it affects linkage, for the variable storage duration). Using a static variable here can lead to races, e.g. when initializing VP9 (for which said function pointer was added) and H.264 with slice threading. The latter has the FF_CODEC_CAP_INIT_THREADSAFE flag set and is therefore unaffected by the lock guarding initializations of decoders. Reviewed-by: Anton Khirnov <anton@khirnov.net> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> (cherry picked from commit 0639f5c294c70c55f4da75ce2ca5bf6c5a809248)
FFmpeg README
FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.
Libraries
libavcodecprovides implementation of a wider range of codecs.libavformatimplements streaming protocols, container formats and basic I/O access.libavutilincludes hashers, decompressors and miscellaneous utility functions.libavfilterprovides a mean to alter decoded Audio and Video through chain of filters.libavdeviceprovides an abstraction to access capture and playback devices.libswresampleimplements audio mixing and resampling routines.libswscaleimplements 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,ismindexandqt-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.