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Ruk Doe
9a4111b1e0
An ARIB caption statement whose data units contain only CS (clear screen) decodes to a caption with the ARIBCC_CAPTIONFLAGS_CLEARSCREEN flag set and region_count == 0. In SUBTITLE_TEXT mode this is translated into a rect holding "" so that the previous caption is erased. In SUBTITLE_BITMAP mode nothing is rendered, the function returns 0 and *got_sub_ptr is left at 0, so the caller never learns that the caption ended. Broadcasters send such a statement at the end of every caption segment (for example when going to a commercial break). Combined with wait_duration == ARIBCC_DURATION_INDEFINITE, which maps to end_display_time = UINT32_MAX, the last caption of a segment stays on screen until the next one arrives - in a real recording that was 22 minutes later. Report an empty subtitle (num_rects = 0) when the clear-screen flag is set, which sub2video and the usual subtitle consumers already treat as "erase". The flag is tested instead of region_count == 0 because a statement containing only TIME also decodes to zero regions but must not erase the currently displayed caption.
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.