[FFmpeg-user] Bad A/V Sync Using ffmpeg on V4L2 Input Device

Lou lou at lrcd.com
Tue Mar 25 00:32:09 CET 2014


On Mon, 24 Mar 2014 01:27:00 -0700
"Leo L. Schwab" <ewhac at ewhac.org> wrote:

> 	Clearly, someone thinks this is fixed, leading me to think that I
> need more magic on the command line.  Here's my latest incantation:
> 
> 	ffmpeg  -f alsa -i hw:1  -f v4l2 -i /dev/video0  -acodec libfaac -b:a 128k -vcodec libx264 -b:v 12M -g 1 -preset ultrafast  SYNCTEST.mp4
> 
> 	Adding various -ts options to the line doesn't seem to accomplish
> anything.  The USB video capture device is a Pinnacle Dazzle DVC 100.  I'm
> using ffmpeg version 2.1.4.  The console output from a sample capture
> session is appended below.

This -ts option is a v4l2 input option. I'm not sure if this option
will solve your issue, but did you place it in the correct location?

ffmpeg -f alsa -i hw:1 -f v4l2 -ts abs -i /dev/video0 ...

I'm only asking because your command and console output does not
include -ts.


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