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Unlike the 8-bit version, we need two iterations to process this within 128-bit vectors. This adds some extra complexity for pointer arithmetic and counting down which is unnecessary in the 8-bit variant. Accordingly the gain relative to C are just slight better than half as good with 128-bit vectors as with 256-bit ones. T-Head C908 (2 iterations): h264_idct8_add_9bpp_c: 17.5 h264_idct8_add_9bpp_rvv_i32: 10.0 h264_idct8_add_10bpp_c: 17.5 h264_idct8_add_10bpp_rvv_i32: 9.7 h264_idct8_add_12bpp_c: 17.7 h264_idct8_add_12bpp_rvv_i32: 9.7 h264_idct8_add_14bpp_c: 17.7 h264_idct8_add_14bpp_rvv_i32: 9.7 SpacemiT X60 (single iteration): h264_idct8_add_9bpp_c: 15.2 h264_idct8_add_9bpp_rvv_i32: 5.0 h264_idct8_add_10bpp_c: 15.2 h264_idct8_add_10bpp_rvv_i32: 5.0 h264_idct8_add_12bpp_c: 14.7 h264_idct8_add_12bpp_rvv_i32: 5.0 h264_idct8_add_14bpp_c: 14.7 h264_idct8_add_14bpp_rvv_i32: 4.7
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.