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aeb138679a
Both GCC and Clang completely unroll the unlikely loop at -O3, leading to codesize bloat; their code is also suboptimal, as they don't make use of pmulhrsw (even with -mssse3). This commit therefore ports the whole function to external assembly. The new function occupies 176B here vs 1406B for GCC. Benchmarks for a testcase with huge qscale (notice that the C version is unrolled just like the unlikely loop in the SSSE3 version): add_8x8basis_c: 43.4 ( 1.00x) add_8x8basis_ssse3 (old): 43.6 ( 1.00x) add_8x8basis_ssse3 (new): 11.9 ( 3.63x) Reviewed-by: Kieran Kunhya <kieran@kunhya.com> Reviewed-by: Lynne <dev@lynne.ee> 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
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 means to alter decoded audio and video through a directed graph of connected 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.