mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2026-10-28 10:04:37 +08:00
Lynne
24e7332342
The CRC of a range coded slice was computed a byte at a time by a single invocation once the slice was coded. All invocations now compute it: each takes a segment of the slice, and the CRCs of the segments are combined, from the first, with a GF(2) matrix that advances a CRC past a segment of zero bytes, whose columns are computed alongside. The table is read from shared memory. The output is unchanged. Encoding a 6464x4852 16-bit RGB frame with 1024 slices on an RX 6900 XT, with the frame in VRAM, goes from 52.9/50.1 ms to 44.2/40.9 ms with context model 1/0.
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.