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Michael Niedermayer
5e56cabf83
Dividing by the attenuation amplifies the noise and the quantization steps of the dark areas by the same factor. The wavelet mode performs the division in the pixel domain, then transforms the result and its per pixel noise variance, propagated through the squared filter taps as if the samples were uncorrelated, with the undecimated 9/7 wavelet. Each detail coefficient is Wiener shrunk toward 0 with a signal variance estimated from a 7x7 box of coefficients at the dilation of the level, weighted by their precision and counted only when it exceeds the noise by 3 standard errors of independent coefficients. The lowpass of the top level averages over large areas and is kept, so the shade of heavily attenuated areas survives. Assisted-by: Claude
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 Forgejo or 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.
See https://ffmpeg.org/developer.html for more information.