mirror of https://git.ffmpeg.org/ffmpeg.git
4d7a1a4619
Up until now, libswscale/input.c used a macro to read an input pixel which involved a call to av_pix_fmt_desc_get() to find out whether the input pixel format is BE or LE despite this being known at compile-time (there are templates per pixfmt). Even worse, these calls are made in a loop, so that e.g. there are six calls to av_pix_fmt_desc_get() for every pair of UV pixel processed in rgb64ToUV_half_c_template(). This commit modifies these macros to ensure that isBE() is evaluated at compile-time. This saved 9743B of .text for me (GCC 11.2, -O3). For a simple RGB64LE->YUV420P transformation like ffmpeg -f lavfi -i haldclutsrc,format=rgba64le -pix_fmt yuv420p \ -threads 1 -t 1:00 -f null - the amount of decicycles spent in rgb64LEToUV_half_c (which is created via the template mentioned above) decreases from 19751 to 5341; for RGBA64BE the number went down from 11945 to 5393. For shared builds (where the call to av_pix_fmt_desc_get() is indirect) the old numbers are 15230 for RGBA64BE and 27502 for RGBA64LE, whereas the numbers with this patch are indistinguishable from the numbers from a static build. Also make the macros that are touched conform to the usual convention of using uppercase names while just at it. Reviewed-by: Anton Khirnov <anton@khirnov.net> Reviewed-by: Paul B Mahol <onemda@gmail.com> Reviewed-by: Michael Niedermayer <michael@niedermayer.cc> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com> |
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| compat | ||
| doc | ||
| ffbuild | ||
| fftools | ||
| libavcodec | ||
| libavdevice | ||
| libavfilter | ||
| libavformat | ||
| libavutil | ||
| libpostproc | ||
| libswresample | ||
| libswscale | ||
| presets | ||
| tests | ||
| tools | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .travis.yml | ||
| CONTRIBUTING.md | ||
| COPYING.GPLv2 | ||
| COPYING.GPLv3 | ||
| COPYING.LGPLv2.1 | ||
| COPYING.LGPLv3 | ||
| CREDITS | ||
| Changelog | ||
| INSTALL.md | ||
| LICENSE.md | ||
| MAINTAINERS | ||
| Makefile | ||
| README.md | ||
| RELEASE | ||
| configure | ||
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
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 means to alter decoded audio and video through a directed graph of connected 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.
- 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 and will be ignored.