7910a2c269
qsort is called indirectly in filter_frame, suggesting its performance criticality. AV_QSORT is substantially faster due to the inlining of the comparison callback. Thus, the increase in performance should be worth the increase in binary size. This optimization is just a low hanging fruit. The trac ticket 1430 is a request for an improved deshake filter. Sample benchmark (x86-64, Haswell, GNU/Linux): File: original from https://trac.ffmpeg.org/ticket/1430 command: ffmpeg -stream_loop 8 -i file.webm -vf deshake=rx=64:ry=64 -f null - Timer truncated at 1024 runs. new: 28260 decicycles in qsort, 1 runs, 0 skips 35570 decicycles in qsort, 2 runs, 0 skips 39010 decicycles in qsort, 4 runs, 0 skips 46897 decicycles in qsort, 8 runs, 0 skips 40442 decicycles in qsort, 16 runs, 0 skips 41611 decicycles in qsort, 32 runs, 0 skips 40345 decicycles in qsort, 64 runs, 0 skips 38967 decicycles in qsort, 128 runs, 0 skips 38647 decicycles in qsort, 256 runs, 0 skips 40238 decicycles in qsort, 512 runs, 0 skips 39676 decicycles in qsort, 1024 runs, 0 skips old: 1740280 decicycles in qsort, 1 runs, 0 skips 923560 decicycles in qsort, 2 runs, 0 skips 511330 decicycles in qsort, 4 runs, 0 skips 309720 decicycles in qsort, 8 runs, 0 skips 194900 decicycles in qsort, 16 runs, 0 skips 142686 decicycles in qsort, 32 runs, 0 skips 112516 decicycles in qsort, 64 runs, 0 skips 98166 decicycles in qsort, 128 runs, 0 skips 88147 decicycles in qsort, 256 runs, 0 skips 88706 decicycles in qsort, 512 runs, 0 skips 86783 decicycles in qsort, 1024 runs, 0 skips Reviewed-by: Nicolas George <george@nsup.org> 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.