[FFmpeg-user] non-monotonous DTS in output stream

Moritz Barsnick barsnick at gmx.net
Thu May 17 21:15:54 EEST 2018

On Thu, May 17, 2018 at 14:57:46 +0200, cedric.dewijs at telfort.nl wrote:

I thought you were getting "/dev/video0: Invalid argument"?


> [matroska @ 0x1c48860] Non-monotonous DTS in output stream 0:0; previous: 3109, current: 2048; changing to 3109. This may result in incorrect timestamps in the output file.

I have never understood why this happens, but *oh well*.

What actual fps does ffmpeg report while processing? Does the camera
deliver the 30 fps, and can ffmpeg handle them (speed=1.0x)? Do you get
dups or drops?

> Is there a way to prevent he above errors?

The v4l2 input device supports an option "-timestamps". You may want to
try its three possible values.

> Is there a way to post-process the output file so VLC can play it?

If the frame's timestamps are borked, and/or frames are duplicated or
missing, probably not. Try your options above first.


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