From: Matthew Rademaker via ffmpeg-devel <ffmpeg-devel@ffmpeg.org>
To: ffmpeg-devel@ffmpeg.org
Cc: Matthew Rademaker <matthew@watchgood.com>
Subject: [FFmpeg-devel] Advice on patch: Decklink flushes most buffered frames at end of video instead of displaying them
Date: Wed, 5 Mar 2025 13:47:11 +1000
Message-ID: <CAGBDY-suNJVT1F7cga+8uW7xfTepdp1GfnG_KRPkfCWLqWAogA@mail.gmail.com> (raw)
When playing out video to a Decklink SDI 4K card I've found that all/most
of the buffered frames get flushed instead of being displayed, essentially
shortening the video by the amount of pre-roll. I found a way to fix this
by adding a counter of outstanding frames, then delaying the call to
StopScheduledPlayback until all frames are returned.
I would submit this as a patch, but this is my first attempt at any ffmpeg
development so I wanted to see if this was the best way to fix this issue.
Are the outstanding frames already counted some other way? Is blocking via
sleep ideal? The StopScheduledPlayback has a pts parameter, which I assume
means that it should only stop playback at that time - should this not
prevent the issue I am seeing? Why would it flush the frames?
Again, I'm new to all this so more information would be great.
--
Matt
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next reply other threads:[~2025-03-05 3:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-05 3:47 Matthew Rademaker via ffmpeg-devel [this message]
2025-03-05 11:50 ` Devin Heitmueller
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