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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2026-06-19 19:03:00 +02:00
Jun Zhao a4317c4ff8 avcodec/webvttdec: map WebVTT cue timestamps to ASS {\kf} tags
Split each cue at its inline timestamps and emit every segment as
"{\kf<cs>}<text>", the duration being the segment's own span (next
timestamp minus current); the tag precedes the text so the karaoke fill
runs during the segment.  Boundaries are rounded to centiseconds against
the cue start and differenced, so durations telescope to the cue length
without drift.  Packet timing uses pkt_timebase rather than assuming a
1/1000 time base.  Out-of-range, non-monotonic and malformed timestamps
are ignored; cues without timestamps are emitted unchanged.

ASS {\kf} only approximates WebVTT timed text (no ::cue(:past/:future)).

Fixes: ticket #23289
Signed-off-by: Jun Zhao <barryjzhao@tencent.com>
2026-06-19 04:33:18 +00:00

FFmpeg README

FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.

Libraries

  • libavcodec provides implementation of a wider range of codecs.
  • libavformat implements streaming protocols, container formats and basic I/O access.
  • libavutil includes hashers, decompressors and miscellaneous utility functions.
  • libavfilter provides means to alter decoded audio and video through a directed graph of connected filters.
  • libavdevice provides an abstraction to access capture and playback devices.
  • libswresample implements audio mixing and resampling routines.
  • libswscale implements 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, ismindex and qt-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.

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