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be8a4f80b9
During a resampling operation where 1) user has specified first_pts 2) SWR_FLAG_RESAMPLE is not set initially (directly or otherwise) 3) first_pts has been fulfilled (always using hard compensation) then upon first encountering a delay where a soft compensation is required, swr_set_compensation will lead to another init of swr which will reset outpts to the specified firstpts thus leading to an output frame having its pts = firstpts. When the next input frame is received, swr will see a large delay and inject silence from firstpts to the current frame's pts. This can lead to severe desync and in worst case, loss of audio playback. Parameter firstpts initialized to AV_NOPTS_VALUE in swr_alloc and then checked in swr_init to avoid resetting outpts, thus avoiding reapplication of firstpts. Fixes #4131.
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.