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This adds a NEON-optimized function for computing 32x32 Sum of Absolute Differences (SAD) on AArch64, addressing a gap where x86 had SSE2/AVX2 implementations but AArch64 lacked equivalent coverage. The implementation mirrors the existing sad8 and sad16 NEON functions, employing a 4-row unrolled loop with UABAL and UABAL2 instructions for efficient load-compute interleaving, and four 8x16-bit accumulators to handle the wider 32-byte rows. Benchmarks on AWS Graviton3 (Neoverse V1, c7g.xlarge) using checkasm: sad_32x32_0: C 146.4 cycles -> NEON 98.1 cycles (1.49x speedup) sad_32x32_1: C 141.4 cycles -> NEON 98.9 cycles (1.43x speedup) sad_32x32_2: C 140.7 cycles -> NEON 95.0 cycles (1.48x speedup) Signed-off-by: Jeongkeun Kim <variety0724@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 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.