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The implementation of ff_read_time() for RISC-V uses rdtime which has precision on existing hardware too low (!) for benchmarking purposes. Deleting this implementation falls back on clock_gettime() which was added as the default ff_read_time() implementation in 33e4cc9. Below are metrics gathered on SpacemiT K1, before and after this commit: Before: $ tests/checkasm/checkasm --bench benchmarking with native FFmpeg timers nop: 0.0 checkasm: using random seed 3473665261 checkasm: bench runs 1024 (1 << 10) RVI: - pixblockdsp.get_pixels [OK] - vc1dsp.mspel_pixels [OK] RVF: - audiodsp.audiodsp [OK] checkasm: all 4 tests passed audiodsp.vector_clipf_c: 1388.7 audiodsp.vector_clipf_rvf: 261.5 get_pixels_c: 2.0 get_pixels_rvi: 1.5 vc1dsp.put_vc1_mspel_pixels_tab[0][0]_c: 8.0 vc1dsp.put_vc1_mspel_pixels_tab[0][0]_rvi: 1.0 vc1dsp.put_vc1_mspel_pixels_tab[1][0]_c: 2.0 vc1dsp.put_vc1_mspel_pixels_tab[1][0]_rvi: 0.5 After: $ tests/checkasm/checkasm --bench benchmarking with native FFmpeg timers nop: 56.4 checkasm: using random seed 1021411603 checkasm: bench runs 1024 (1 << 10) RVI: - pixblockdsp.get_pixels [OK] - vc1dsp.mspel_pixels [OK] RVF: - audiodsp.audiodsp [OK] checkasm: all 4 tests passed audiodsp.vector_clipf_c: 23236.4 audiodsp.vector_clipf_rvf: 11038.4 get_pixels_c: 79.6 get_pixels_rvi: 48.4 vc1dsp.put_vc1_mspel_pixels_tab[0][0]_c: 329.6 vc1dsp.put_vc1_mspel_pixels_tab[0][0]_rvi: 38.1 vc1dsp.put_vc1_mspel_pixels_tab[1][0]_c: 89.9 vc1dsp.put_vc1_mspel_pixels_tab[1][0]_rvi: 17.1 Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
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.