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For coefficients and output that both span 16 bits, like those of ProRes RAW. The template's 16-bit intermediates cannot hold more fractional bits than the output needs, and the constants of the 12-bit transform, scaled to 15 bits, make W4 32767 rather than 32768, which alone costs 0.8 LSB RMS of a 16-bit output. The new variant uses the 10-bit transform's constants, scaled to 14 bits and exact at W4, with a row shift of 13 and a column shift of 15, the most fractional bits the 32-bit sums of a 16-bit result allow. Against an exact transform, it is within 0.49 LSB RMS and 2.3 LSB peak on real content, with no bias, and passes every IEEE 1180 criterion in the standard's 8-bit units by three orders of magnitude. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_016LFnYMstwe4woBzpxfzDzg
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.