Mixing multiple sources with different framerates

[Eduardo Herraiz]

Hi all, 

I am trying to mix 3 different sources with Gstreamer.
 
I have 2 usb cams and a usb framegrabber capturing a VGA laptop exit.
http://ifisc.uib-csic.es/~edu/screens_gstreamer/allsources.png

It works, but with a very slow framerate. I suppose that is a problem with the different bitrates of the sources, because the framegrabber has a 10 fps an the others 25 fps.
And in console I can see errors, every second, like this: "There may be a timestamping problem, or this computer is too slow."
This is the command I used:
 gst-launch-0.10 \
  videomixer2 name=mix ! xvimagesink \
   v4l2src device="/dev/video0" ! video/x-raw-yuv,width=640,height=480 ! videoscale ! video/x-raw-yuv,width=512,height=384 ! ffmpegcolorspace ! \
     videobox border-alpha=0 top=-384 left=0 ! mix. \
   v4l2src device="/dev/video1" ! video/x-raw-yuv,width=720,height=576 ! videoscale ! video/x-raw-yuv,width=512,height=384 ! ffmpegcolorspace ! \
     videobox border-alpha=0 top=0 left=0 ! mix. \
   v4l2src device="/dev/video2" ! video/x-raw-yuv,width=1024,height=768 ! ffmpegcolorspace  ! \
      videobox border-alpha=0 top=0 left=-512 ! mix.

When I try without the slow source, seems to work properly.
http://ifisc.uib-csic.es/~edu/screens_gstreamer/twosources.png


I have no idea how to solve this and if is possible to merge, in a correct way, different sources with variable bitrates, 
Anybody knows?

This link was helpful for me and I based my work on it:
http://www.oz9aec.net/index.php/gstreamer/347-more-gstreamer-tips-picture-in-picture-compositing

Thank you
Edu


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Edu Herraiz - Web developer
http://www.eduherraiz.com

IFISC
Instituto de Física Interdisciplinar y Sistemas Complejos (CSIC-UIB)
email: edu at ifisc.uib-csic.es
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