Opened 2 years ago

Last modified 2 years ago

#6481 open defect

ffplay - Video from capture device slowly falls behind

Reported by: LordHDL Owned by: thilo.borgmann
Priority: normal Component: ffplay
Version: git-master Keywords:
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no


Summary of the bug: When displaying video from a capture device (in my case: Magewell USB HDMI Plus), the video will gradually fall behind. Right clicking on the window syncs it. This is on macOS using AVFoundation.
How to reproduce: Use a command like the following to preview device capture output.

ffplay -f avfoundation -pix_fmt 0rgb -framerate 60 -i "1:none"

Change History (2)

comment:1 Changed 2 years ago by LordHDL

Apparently this happens when selecting "none" for the audio stream. Including audio causes the -framedrop (default) option to work properly instead of filling the buffer.

comment:2 Changed 2 years ago by thilo.borgmann

  • Owner set to thilo.borgmann
  • Status changed from new to open

Does the same asynchronous behaviour appear when just recording with ffmpeg?
Synch by right-clicking the window means that the late frames are getting skipped?
Does changing the framerate or the setpts filter have any effect on the issue?

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