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- C 89.5%
- Assembly 8.3%
- Makefile 1.3%
- C++ 0.3%
- GLSL 0.2%
- Other 0.2%
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Add NEON-optimized implementation for HEVC intra Planar prediction at
8-bit depth, supporting all block sizes (4x4 to 32x32).
Planar prediction implements bilinear interpolation using an incremental
base update: base_{y+1}[x] = base_y[x] - (top[x] - left[N]), reducing
per-row computation from 4 multiply-adds to 1 subtract + 1 multiply.
Uses rshrn for rounded narrowing shifts, eliminating manual rounding
bias. All left[y] values are broadcast in the NEON domain, avoiding
GP-to-NEON transfers.
4x4 interleaves row computations across 4 rows to break dependencies.
16x16 uses v19-v22 for persistent base/decrement vectors, avoiding
callee-saved register spills. 32x32 processes 8 rows per loop iteration
(4 iterations total) to reduce code size while maintaining full NEON
utilization.
Speedup over C on Apple M4 (checkasm --bench):
4x4: 2.25x 8x8: 6.40x 16x16: 9.72x 32x32: 3.21x
Signed-off-by: Jun Zhao <barryjzhao@tencent.com>
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| libavcodec | ||
| libavdevice | ||
| libavfilter | ||
| libavformat | ||
| libavutil | ||
| libswresample | ||
| libswscale | ||
| presets | ||
| tests | ||
| tools | ||
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| .mailmap | ||
| Changelog | ||
| configure | ||
| CONTRIBUTING.md | ||
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| COPYING.GPLv3 | ||
| COPYING.LGPLv2.1 | ||
| COPYING.LGPLv3 | ||
| CREDITS | ||
| FUNDING.json | ||
| INSTALL.md | ||
| LICENSE.md | ||
| MAINTAINERS | ||
| Makefile | ||
| README.md | ||
| RELEASE | ||
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.