68a0a164d1
filter_slice calls qsort, so qsort is in a performance critical position. AV_QSORT is substantially faster due to the inlining of the comparison callback. Thus, the increase in performance is worth the increase in binary size. Sample benchmark (x86-64, Haswell, GNU/Linux), filter-removegrain-mode-02 (from FATE) new: 24060 decicycles in qsort, 1 runs, 0 skips 15690 decicycles in qsort, 2 runs, 0 skips 9307 decicycles in qsort, 4 runs, 0 skips 5572 decicycles in qsort, 8 runs, 0 skips 3485 decicycles in qsort, 16 runs, 0 skips 2517 decicycles in qsort, 32 runs, 0 skips 1979 decicycles in qsort, 64 runs, 0 skips 1911 decicycles in qsort, 128 runs, 0 skips 1568 decicycles in qsort, 256 runs, 0 skips 1596 decicycles in qsort, 512 runs, 0 skips 1614 decicycles in qsort, 1024 runs, 0 skips 1874 decicycles in qsort, 2046 runs, 2 skips 2186 decicycles in qsort, 4094 runs, 2 skips old: 246960 decicycles in qsort, 1 runs, 0 skips 135765 decicycles in qsort, 2 runs, 0 skips 70920 decicycles in qsort, 4 runs, 0 skips 37710 decicycles in qsort, 8 runs, 0 skips 20831 decicycles in qsort, 16 runs, 0 skips 12225 decicycles in qsort, 32 runs, 0 skips 8083 decicycles in qsort, 64 runs, 0 skips 6270 decicycles in qsort, 128 runs, 0 skips 5321 decicycles in qsort, 256 runs, 0 skips 4860 decicycles in qsort, 512 runs, 0 skips 4424 decicycles in qsort, 1024 runs, 0 skips 4191 decicycles in qsort, 2046 runs, 2 skips 4934 decicycles in qsort, 4094 runs, 2 skips 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.