forked from FFmpeg/FFmpeg
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dddf536d3d
The underlying color mapping logic was ported as straightforwardly as possible from libplacebo, although the API and glue code has been very heavily refactored / rewritten. In particular, the generalization of gamut mapping methods is replaced by a single ICC intent selection, and constants have been hard-coded. To minimize the amount of overall operations, this gamut mapping LUT now embeds a direct end-to-end transformation to the output color space; something that libplacebo does in shaders, but which is prohibitively expensive in software. In order to preserve compatibility with dynamic tone mapping without severely regressing performance, we add the ability to generate a pair of "split" LUTS, one for encoding the input and output to the perceptual color space, and a third to embed the tone mapping operation. Additionally, this intermediate space could be used for additional subjective effect (e.g. changing saturation or brightness). The big downside of the new approach is that generating a static color mapping LUT is now fairly slow, as the chromaticity lobe peaks have to be recomputed for every single RGB value, since correlated RGB colors are not necessarily aligned in ICh space. Generating a split 3DLUT significantly alleviates this problem because the expensive step is done as part of the IPT input LUT, which can share the same hue peak calculation at least for all input intensities. |
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| compat | ||
| doc | ||
| ffbuild | ||
| fftools | ||
| libavcodec | ||
| libavdevice | ||
| libavfilter | ||
| libavformat | ||
| libavutil | ||
| libpostproc | ||
| libswresample | ||
| libswscale | ||
| presets | ||
| tests | ||
| tools | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| Changelog | ||
| configure | ||
| CONTRIBUTING.md | ||
| COPYING.GPLv2 | ||
| COPYING.GPLv3 | ||
| COPYING.LGPLv2.1 | ||
| COPYING.LGPLv3 | ||
| CREDITS | ||
| INSTALL.md | ||
| LICENSE.md | ||
| MAINTAINERS | ||
| Makefile | ||
| README.md | ||
| RELEASE | ||
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.