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Devin Heitmueller 8fd345f018 avdevice/decklink_enc: don't take for granted that first frame to decklink output will be PTS 0
The existing code assumed that the first frame received by the decklink
output would always be PTS zero.  However if running in other timing
modes than the default of CBR, items such as frame dropping at the
beginning may result in starting at a non-zero PTS.

For example, in our setup because we discard probing data and run
with "-vsync 2" the first video frame scheduled to the decklink
output will have a PTS around 170.  Scheduling frames too far into
the future will either fail or cause a backlog of frames scheduled
far enough into the future that the entire pipeline will stall.

Issue can be reproduced with the following command-line:

./ffmpeg -copyts -i foo.ts -f decklink -vcodec v210 -ac 2  'DeckLink Duo (4)'

Keep track of the PTS of the first frame received, so that when
we enable start playback we can provide that value to the decklink
driver.

Thanks to Marton Balint for review and suggestion to use
AV_NOPTS_VALUE rather than zero for the initial value.

Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com>
Signed-off-by: Marton Balint <cus@passwd.hu>
2023-03-08 23:53:15 +01:00
2023-03-02 18:59:37 +01:00
2022-03-17 18:35:41 -03:00
2023-03-01 21:59:10 +01:00
2022-07-13 00:31:42 +02:00

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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