RepoMirrors/ffmpeg
1
0
Fork 0
mirror of https://git.ffmpeg.org/ffmpeg.git synced 2024-12-27 09:52:17 +00:00
Code Issues Projects Releases Wiki Activity
FFmpeg git repo
77,547 Commits 37 Branches 400 Tags 245 MiB
C 90.3%
Assembly 7.8%
Makefile 1.3%
C++ 0.2%
Objective-C 0.2%
Other 0.1%
05434b0eea
Go to file
Ganesh Ajjanagadde 05434b0eea lavc/cook: get rid of wasteful pow in init_pow2table 
The table is highly structured, so pow (or exp2 for that matter) can entirely
be avoided, yielding a ~ 40x speedup with no loss of accuracy.

sample benchmark (Haswell, GNU/Linux):
new:
4449 decicycles in init_pow2table(loop 1000),     254 runs,      2 skips
4411 decicycles in init_pow2table(loop 1000),     510 runs,      2 skips
4391 decicycles in init_pow2table(loop 1000),    1022 runs,      2 skips

old:
183673 decicycles in init_pow2table(loop 1000),     256 runs,      0 skips
182142 decicycles in init_pow2table(loop 1000),     512 runs,      0 skips
182104 decicycles in init_pow2table(loop 1000),    1024 runs,      0 skips

Reviewed-by: Clément Bœsch <u@pkh.me>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
2015-12-30 08:52:19 -08:00
compat os2threads: Add pthread_once() 2015-11-12 22:31:46 +01:00
doc avfilter/avf_showspectrum: add rainbow colormap 2015-12-29 19:53:38 +01:00
libavcodec lavc/cook: get rid of wasteful pow in init_pow2table 2015-12-30 08:52:19 -08:00
libavdevice lavd/pulse_audio_enc: replace lround by lrint 2015-12-21 08:25:30 -08:00
libavfilter avfilter/avf_showspectrum: add rainbow colormap 2015-12-29 19:53:38 +01:00
libavformat oggparsedaala: check number of planes in pixel format map 2015-12-29 18:42:14 +01:00
libavresample Merge commit 'e2854e731f843906d9a9a5b882bed872341999fd' 2015-11-10 18:07:41 +01:00
libavutil lavu/eval: replace pow(10,x) by ff_exp10(x) 2015-12-25 10:48:13 -08:00
libpostproc
libswresample swr/resample: use av_clip_int16 instead of av_clip 2015-12-24 11:29:52 -08:00
libswscale swscale/utils: Fix intermediate format for cascaded alpha downscaling 2015-12-24 21:46:15 +01:00
presets
tests lavc: add text encoder 2015-12-21 11:14:02 +01:00
tools tools/bookmarklets: HTML code fixes 2015-12-25 17:54:58 +01:00
.gitattributes
.gitignore gitignore: ignore object file temporaries 2015-10-10 20:30:41 +02:00
.travis.yml Merge commit 'eda183287489b2c705843aa373a19c4e46fb2fec' 2015-11-22 17:12:24 +00:00
arch.mak mips: rename mipsdspr1 to mipsdsp 2015-12-04 02:35:42 +01:00
Changelog lavf: add automatic bitstream filtering; bump version 2015-12-28 08:40:35 -06:00
cmdutils_common_opts.h
cmdutils_opencl.c all: use FFDIFFSIGN to resolve possible undefined behavior in comparators 2015-11-03 16:28:30 -05:00
cmdutils.c cosmetics: Fix weird indentations 2015-12-07 10:43:43 -08:00
cmdutils.h
common.mak Merge commit '9f57f134c19773d54269b6cb9ee455ff87c2e9e1' 2015-12-05 12:21:33 +01:00
configure configure: make gcc 2 detection more robust 2015-12-30 08:45:02 -08:00
COPYING.GPLv2
COPYING.GPLv3
COPYING.LGPLv2.1
COPYING.LGPLv3
CREDITS
ffmpeg_dxva2.c ffmpeg_dxva2: support vp9 hwaccel 2015-12-07 09:47:51 +01:00
ffmpeg_filter.c ffmpeg_filter: remove redundant null ptr check 2015-11-11 01:51:52 +01:00
ffmpeg_opt.c ffmpeg: use lavf API for applying bitstream filters 2015-12-28 08:34:30 -06:00
ffmpeg_qsv.c Merge commit 'fb472e1a11a4e0caed2c3c91da01ea8e35d9e3f8' 2015-10-22 16:18:02 +02:00
ffmpeg_vdpau.c
ffmpeg_videotoolbox.c ffmpeg/videotoolbox: protect UTGetOSTypeFromString on both VDA and VT 2015-10-15 10:22:31 +02:00
ffmpeg.c ffmpeg: use lavf API for applying bitstream filters 2015-12-28 08:34:30 -06:00
ffmpeg.h ffmpeg: use lavf API for applying bitstream filters 2015-12-28 08:34:30 -06:00
ffplay.c Revert "ffplay: Fix auto insertion point of rotation filter" 2015-12-28 03:44:31 +01:00
ffprobe.c ffprobe: avoid unnecessary pow and exp2 calls 2015-12-29 08:59:16 -08:00
ffserver_config.c ffserver_config: check for INT_MIN before doing FFABS 2015-10-13 19:40:09 -04:00
ffserver_config.h
ffserver.c ffserver: Cast time_t value when using it in a format string. 2015-12-29 16:00:34 +01:00
INSTALL.md
library.mak
LICENSE.md
MAINTAINERS MAINTAINERS: add Eran Kornblau for aes_ctr and movenccenc 2015-12-22 13:57:55 +01:00
Makefile mips: rename mipsdspr1 to mipsdsp 2015-12-04 02:35:42 +01:00
README.md
RELEASE
version.sh version.sh: add note that ffversion.h is auto-generated 2015-10-25 10:14:44 -04:00

README.md

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 and qt-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.