No description
22e960ad47
Also correct the check to reject log < 7, because UPDATE_CACHE only
guarantees 25 meaningful bits.
This fixes undefined behavior:
runtime error: shift exponent is negative
Testing with START/STOP timers in get_ue_golomb, one for the first
branch (A) and one for the second (B), shows that there is practically no
slowdown, e.g. for the cavs decoder:
With the check in the B branch:
629 decicycles in get_ue_golomb B, 4194260 runs, 44 skips
433 decicycles in get_ue_golomb A,268434102 runs, 1354 skips
Without the check:
624 decicycles in get_ue_golomb B, 4194273 runs, 31 skips
433 decicycles in get_ue_golomb A,268434203 runs, 1253 skips
Since the B branch is executed far less often than the A branch, this
change is negligible, even more so for the h264 decoder, where the ratio
B/A is a lot smaller.
Fixes: mozilla bug 1230239
Fixes: fbeb8b2c7c996e9b91c6b1af319d7ebc/asan_heap-oob_195450f_2743_e8856ece4579ea486670be2b236099a0.bit
Found-by: Tyson Smith
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
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|---|---|---|
| compat | ||
| doc | ||
| libavcodec | ||
| libavdevice | ||
| libavfilter | ||
| libavformat | ||
| libavresample | ||
| libavutil | ||
| libpostproc | ||
| libswresample | ||
| libswscale | ||
| presets | ||
| tests | ||
| tools | ||
| .gitattributes | ||
| .gitignore | ||
| .travis.yml | ||
| arch.mak | ||
| Changelog | ||
| cmdutils.c | ||
| cmdutils.h | ||
| cmdutils_common_opts.h | ||
| cmdutils_opencl.c | ||
| common.mak | ||
| configure | ||
| COPYING.GPLv2 | ||
| COPYING.GPLv3 | ||
| COPYING.LGPLv2.1 | ||
| COPYING.LGPLv3 | ||
| CREDITS | ||
| ffmpeg.c | ||
| ffmpeg.h | ||
| ffmpeg_dxva2.c | ||
| ffmpeg_filter.c | ||
| ffmpeg_opt.c | ||
| ffmpeg_qsv.c | ||
| ffmpeg_vdpau.c | ||
| ffmpeg_videotoolbox.c | ||
| ffplay.c | ||
| ffprobe.c | ||
| ffserver.c | ||
| ffserver_config.c | ||
| ffserver_config.h | ||
| INSTALL.md | ||
| library.mak | ||
| LICENSE.md | ||
| MAINTAINERS | ||
| Makefile | ||
| README.md | ||
| RELEASE | ||
| version.sh | ||
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.
- ffserver is a multimedia streaming server for live broadcasts.
- 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. Few developers
follow pull requests so they will likely be ignored.