No description
e29db08cf7
exp10 is a function available in GNU libm. Looks like no other common libm has it. This adds support for it to FFmpeg. There are essentially 2 ways of handling the fallback: 1. Using pow(10, x) 2. Using exp2(M_LOG2_10 * x). First one represents a Pareto improvement, with no speed or accuracy regression anywhere, but speed improvement limited to GNU libm. Second one represents a slight accuracy loss (relative error ~ 1e-13) for non GNU libm. Speedup of > 2x is obtained on non GNU libm platforms, ~30% on GNU libm. These are "average case numbers", another benefit is the lack of triggering of the well-known terrible worst case paths through pow. Based on reviews, second one chosen. Comment added accordingly. Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com> Reviewed-by: Michael Niedermayer <michael@niedermayer.cc> Reviewed-by: Ronald S. Bultje <rsbultje@gmail.com> 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.c | ||
| cmdutils.h | ||
| cmdutils_common_opts.h | ||
| cmdutils_opencl.c | ||
| common.mak | ||
| configure | ||
| COPYING.GPLv2 | ||
| COPYING.GPLv3 | ||
| COPYING.LGPLv2.1 | ||
| COPYING.LGPLv3 | ||
| CREDITS | ||
| ffmpeg.c | ||
| ffmpeg.h | ||
| ffmpeg_dxva2.c | ||
| ffmpeg_filter.c | ||
| ffmpeg_opt.c | ||
| ffmpeg_qsv.c | ||
| ffmpeg_vdpau.c | ||
| ffmpeg_videotoolbox.c | ||
| ffplay.c | ||
| ffprobe.c | ||
| ffserver.c | ||
| ffserver_config.c | ||
| ffserver_config.h | ||
| 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
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. Few developers
follow pull requests so they will likely be ignored.