259dc4e013
Previously the codec kept an entire copy of the SPS, and restarted the VT decoder session whenever it changed. This fixed decoding errors in [1], as described in 9519983c. On further inspection, that sample features an SPS change from High/4.0 to High/3.2 while moving from one scene to another. Yesterday I received [2], which contains minor SPS changes where the profile and level do not change. These occur frequently and are not associated with scene changes. After 9519983c, the VT decoder session is recreated unnecessarily when these are encountered causing visual glitches. This commit simplifies the state kept in the VTContext to include just the first three bytes of the SPS, containing the profile and level details. This is populated initially when the VT decoder session is created, and used to detect changes and force a restart. This means minor SPS changes are fed directly into the existing decoder, whereas profile/level changes force the decoder session to be recreated with the new parameters. After this commit, both samples [1] and [2] playback as expected. [1] https://s3.amazonaws.com/tmm1/videotoolbox/spschange.ts [2] https://s3.amazonaws.com/tmm1/videotoolbox/spschange2.ts Signed-off-by: Aman Gupta <aman@tmm1.net>
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.
- ffserver is a multimedia streaming server for live broadcasts.
- 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.