a5b6e29227
Currently AVBR is disabled and VBR is the default method if maxrate is not specified on Linux, but AVBR is the default one if maxrate is not specified on Windows. In order to make user experience better accross Linux and Windows, use VBR by default on Windows if maxrate is not specified. User need to set both avbr_accuracy and avbr_convergence to non-zero explicitly and not to specify maxrate if AVBR is expected. In addition, AVBR works for H264 and HEVC only in the SDK. $ ffmpeg.exe -v verbose -f lavfi -i yuvtestsrc -vf "format=nv12" -c:v vp9_qsv -f null -
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.