mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2026-06-16 04:32:47 +02:00
Andreas Rheinhardt
fefe2cbbf2
The Smacker Huffman tables are already stored in a tree-like structure; in particular, they are naturally ordered from left to right in the tree and are therefore suitable to be initialized by ff_init_vlc_from_lengths() which avoids traversing the data twice in order to sort only the codes that are so long that they need into a subtable. This improves performance (and reduces codesize): For the sample from ticket #2425 the number of decicycles for parsing and creating the VLCs in smka_decode_frame() decreased from 412322 to 359152 (tested with 10 runs each looping 20 times over the file). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
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 a mean to alter decoded Audio and Video through chain of 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.