717cc82d28
For widths of 32 pixels and more, loop first horizontally, then vertically. Previously, this function would process a 16 pixel wide slice of the block, looping vertically. After processing the whole height, it would backtrack and process the next 16 pixel wide slice. When doing 8tap filtering horizontally, the function must load 7 more pixels (in practice, 8) following the actual inputs, and this was done for each slice. By iterating first horizontally throughout each line, then vertically, we access data in a more cache friendly order, and we don't need to reload data unnecessarily. Keep the original order in put_hevc_\type\()_h12_8_neon; the only suboptimal case there is for width=24. But specializing an optimal variant for that would require more code, which might not be worth it. For the h16 case, this implementation would give a slowdown, as it now loads the first 8 pixels separately from the rest, but for larger widths, it is a gain. Therefore, keep the h16 case as it was (but remove the outer loop), and create a new specialized version for horizontal looping with 16 pixels at a time. Before: Cortex A53 A72 A73 Graviton 3 put_hevc_qpel_h16_8_neon: 710.5 667.7 692.5 211.0 put_hevc_qpel_h32_8_neon: 2791.5 2643.5 2732.0 883.5 put_hevc_qpel_h64_8_neon: 10954.0 10657.0 10874.2 3241.5 After: put_hevc_qpel_h16_8_neon: 697.5 663.5 705.7 212.5 put_hevc_qpel_h32_8_neon: 2767.2 2684.5 2791.2 920.5 put_hevc_qpel_h64_8_neon: 10559.2 10471.5 10932.2 3051.7 Signed-off-by: Martin Storsjö <martin@martin.st>
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.