You've already forked FFmpeg
mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2025-08-10 06:10:52 +02:00
ceb36b8178
This work is sponsored by, and copyright, Google.
Compared to the arm version, on aarch64 we can keep the full 8x8
transform in registers, and for 16x16 and 32x32, we can process
it in slices of 4 pixels instead of 2.
Examples of runtimes vs the 32 bit version, on a Cortex A53:
ARM AArch64
vp9_inv_adst_adst_4x4_sub4_add_10_neon: 111.0 109.7
vp9_inv_adst_adst_8x8_sub8_add_10_neon: 914.0 733.5
vp9_inv_adst_adst_16x16_sub16_add_10_neon: 5184.0 3745.7
vp9_inv_dct_dct_4x4_sub1_add_10_neon: 65.0 65.7
vp9_inv_dct_dct_4x4_sub4_add_10_neon: 100.0 96.7
vp9_inv_dct_dct_8x8_sub1_add_10_neon: 111.0 119.7
vp9_inv_dct_dct_8x8_sub8_add_10_neon: 618.0 494.7
vp9_inv_dct_dct_16x16_sub1_add_10_neon: 295.1 284.6
vp9_inv_dct_dct_16x16_sub2_add_10_neon: 2303.2 1883.9
vp9_inv_dct_dct_16x16_sub8_add_10_neon: 2984.8 2189.3
vp9_inv_dct_dct_16x16_sub16_add_10_neon: 3890.0 2799.4
vp9_inv_dct_dct_32x32_sub1_add_10_neon: 1044.4 1012.7
vp9_inv_dct_dct_32x32_sub2_add_10_neon: 13333.7 9695.1
vp9_inv_dct_dct_32x32_sub16_add_10_neon: 18531.3 12459.8
vp9_inv_dct_dct_32x32_sub32_add_10_neon: 24470.7 16160.2
vp9_inv_wht_wht_4x4_sub4_add_10_neon: 83.0 79.7
The larger transforms are significantly faster than the corresponding
ARM versions.
The speedup vs C code is smaller than in 32 bit mode, probably
because the 64 bit intermediates in the C code can be expressed
more efficiently in aarch64.
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 a mean to alter decoded Audio and Video through chain of 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.
- ffserver is a multimedia streaming server for live broadcasts.
- 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.