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e1782fb016
This function is exported, so has to abide by the ABI
and therefore issues emms since commit
5b85ca5317. Yet this is
expensive and using SSE2 instead improves performance.
Also avoid the initial zeroing and the last pointer
increment while just at it.
This removes the last usage of mmx from libavutil*.
Old benchmarks:
sad_8x8_0_c: 13.2 ( 1.00x)
sad_8x8_0_mmxext: 27.8 ( 0.48x)
sad_8x8_1_c: 13.2 ( 1.00x)
sad_8x8_1_mmxext: 27.6 ( 0.48x)
sad_8x8_2_c: 13.3 ( 1.00x)
sad_8x8_2_mmxext: 27.6 ( 0.48x)
New benchmarks:
sad_8x8_0_c: 13.3 ( 1.00x)
sad_8x8_0_sse2: 11.7 ( 1.13x)
sad_8x8_1_c: 13.8 ( 1.00x)
sad_8x8_1_sse2: 11.6 ( 1.20x)
sad_8x8_2_c: 13.2 ( 1.00x)
sad_8x8_2_sse2: 11.8 ( 1.12x)
Hint: Using two psadbw or one psadbw and movhps made no difference
in the benchmarks, so I chose the latter due to smaller codesize.
*: except if lavu provides avpriv_emms for other libraries
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.