c1b6acde36
Matroska uses variable-length elements and in order not to waste bytes on length fields, the length of the data to write needs to be known before writing the length field. Annex B H.264/5 and WavPack need to be reformatted to know this length and this currently involves writing the data into temporary buffers; AV1 sometimes suffers from this as well. This commit aims to solve this by adding a callback that is called twice per packet: Once to get the size and once to actually write the data. In case of WavPack and AV1 (where parsing is cheap due to length fields) both calls will just parse the data with only the second function writing anything. For H.264/5, the position of the NALUs will need to be stored to be written lateron. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.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 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.