0b342a2f15
In MPEG-2 user data, there can be different types of Closed Captions formats embedded (A53, SCTE-20, or DVD). The current behavior of the CC extraction code in the MPEG-2 decoder is to not be aware of multiple formats if multiple exist, therefore allowing one format to overwrite the other during the extraction process since the CC extraction shares one output buffer for the normalized bytes. This causes sources that have two CC formats to produce flawed output. There exist real-world samples which contain both A53 and SCTE-20 captions in the same MPEG-2 stream, and that manifest this problem. Example of symptom: THANK YOU (expected) --> THTHANANK K YOYOUU (actual) The solution is to pick only the first CC substream observed with valid bytes, and ignore the other types. Additionally, provide an option for users to manually "force" a type in the event that this matters for a particular source. Signed-off-by: Marth64 <marth64@proxyid.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 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.