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c3a17ffff6
This patch rewrites the innermost loop of ff_yuv2planeX_8_neon to avoid zips and horizontal adds by using fused multiply adds. The patch also uses ld1r to load one element and replicate it across all lanes of the vector. The patch also improves the clipping code by removing the shift right instructions and performing the shift with the shift-right narrow instructions. I see 8% difference on an m6g instance with neoverse-n1 CPUs: $ ffmpeg -nostats -f lavfi -i testsrc2=4k:d=2 -vf bench=start,scale=1024x1024,bench=stop -f null - before: t:0.014015 avg:0.014096 max:0.015018 min:0.013971 after: t:0.012985 avg:0.013013 max:0.013996 min:0.012818 Tested with `make check` on aarch64-linux. Signed-off-by: Sebastian Pop <spop@amazon.com> Reviewed-by: Clément Bœsch <u@pkh.me> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
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.