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Mirror of https://git.ffmpeg.org/ffmpeg.git
9bc3d3355f
ff_huff_build_tree uses qsort underneath. AV_QSORT is substantially faster due to the inlining of the comparison callback. Furthermore, this code is reasonably performance critical, since in e.g the fraps codec, ff_huff_build_tree is called on every frame. This routine is also called in vp6 on every frame in some circumstances. Sample benchmark (x86-64, Haswell, GNU/Linux), vp6 from FATE: vp6 (old): 78930 decicycles in qsort, 1 runs, 0 skips 45330 decicycles in qsort, 2 runs, 0 skips 27825 decicycles in qsort, 4 runs, 0 skips 17471 decicycles in qsort, 8 runs, 0 skips 12296 decicycles in qsort, 16 runs, 0 skips 9554 decicycles in qsort, 32 runs, 0 skips 8404 decicycles in qsort, 64 runs, 0 skips 7405 decicycles in qsort, 128 runs, 0 skips 6740 decicycles in qsort, 256 runs, 0 skips 7540 decicycles in qsort, 512 runs, 0 skips 9498 decicycles in qsort, 1024 runs, 0 skips 9938 decicycles in qsort, 2048 runs, 0 skips 8043 decicycles in qsort, 4095 runs, 1 skips vp6 (new): 15880 decicycles in qsort, 1 runs, 0 skips 10730 decicycles in qsort, 2 runs, 0 skips 10155 decicycles in qsort, 4 runs, 0 skips 7805 decicycles in qsort, 8 runs, 0 skips 6883 decicycles in qsort, 16 runs, 0 skips 6305 decicycles in qsort, 32 runs, 0 skips 5854 decicycles in qsort, 64 runs, 0 skips 5152 decicycles in qsort, 128 runs, 0 skips 4452 decicycles in qsort, 256 runs, 0 skips 4161 decicycles in qsort, 511 runs, 1 skips 4081 decicycles in qsort, 1023 runs, 1 skips 4072 decicycles in qsort, 2047 runs, 1 skips 4004 decicycles in qsort, 4095 runs, 1 skips Reviewed-by: Timothy Gu <timothygu99@gmail.com> Reviewed-by: Michael Niedermayer <michael@niedermayer.cc> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com> |
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compat | ||
doc | ||
libavcodec | ||
libavdevice | ||
libavfilter | ||
libavformat | ||
libavresample | ||
libavutil | ||
libpostproc | ||
libswresample | ||
libswscale | ||
presets | ||
tests | ||
tools | ||
.gitattributes | ||
.gitignore | ||
.travis.yml | ||
arch.mak | ||
Changelog | ||
cmdutils_common_opts.h | ||
cmdutils_opencl.c | ||
cmdutils.c | ||
cmdutils.h | ||
common.mak | ||
configure | ||
COPYING.GPLv2 | ||
COPYING.GPLv3 | ||
COPYING.LGPLv2.1 | ||
COPYING.LGPLv3 | ||
CREDITS | ||
ffmpeg_dxva2.c | ||
ffmpeg_filter.c | ||
ffmpeg_opt.c | ||
ffmpeg_qsv.c | ||
ffmpeg_vdpau.c | ||
ffmpeg_videotoolbox.c | ||
ffmpeg.c | ||
ffmpeg.h | ||
ffplay.c | ||
ffprobe.c | ||
ffserver_config.c | ||
ffserver_config.h | ||
ffserver.c | ||
INSTALL.md | ||
library.mak | ||
LICENSE.md | ||
MAINTAINERS | ||
Makefile | ||
README.md | ||
RELEASE | ||
version.sh |
FFmpeg README
FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.
Libraries
libavcodec
provides implementation of a wider range of codecs.libavformat
implements streaming protocols, container formats and basic I/O access.libavutil
includes hashers, decompressors and miscellaneous utility functions.libavfilter
provides a mean to alter decoded Audio and Video through chain of filters.libavdevice
provides an abstraction to access capture and playback devices.libswresample
implements audio mixing and resampling routines.libswscale
implements 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
,ismindex
andqt-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. Few developers
follow pull requests so they will likely be ignored.