2bcec40cce
Since c737f6edcef74a64f4d0ebcefa970bd31266d512 prescreening is nevertheless run because of a wrong check: "if (s->prescreen > 0)". s->prescreen is an array of two function pointers that is contained in the context and comparing it with 0 (i.e. NULL) is actually undefined behaviour, because NULL and s->prescreen do not point to the same object (NULL after all never points to any object). Nevertheless both Clang as well as GCC compile this to code that treat s->prescreen > 0 as true, leading to segfaults, because the code then tries to access the -1th member of an array. This commit fixes the check as well as another such check a few lines below. (Found via compiler warnings enabled by -pedantic: "ordered comparison between pointer and zero is an extension".) Reviewed-by: Paul B Mahol <onemda@gmail.com> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
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.