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Ayoub Nabil
2312ae4d10
The float decoder dequantized spectral coefficients into an int32_t buffer using mantissa >> exponent. This discarded the fractional part before conversion to float and substantially raised the dither noise floor for low-level coefficients. Store decoded coefficients as INTFLOAT and apply 2^-exponent directly in the floating-point path. Keep the fixed-point decoder unchanged, and perform coupling, rematrixing and final scaling in the native type. This also removes the now-unused fmtconvert dependency. Add a synthetic FATE test that measures the corrected dither level. Existing PCM references remain within one sample except fate-ac3-2.0, whose measured maximum difference is two samples. Fixes #23684.
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.