[gst-devel] Grabbing snapshots out of live stream

[Arnout Vandecappelle]

On Monday 12 January 2009 21:24:20 OB Lutz wrote:
> gst-launch -vvv gstrtpbin name=rtpbin \
>               tcpserversrc host=127.0.0.1 port=1235 ! videoparse
> format=YUY2 width=404 height=424 framerate=20/1 bpp=16 ! \ tee
> name=splitter splitter.  ! queue ! typefind ! pngenc snapshot=false !
> multifilesink sync=false preroll-queue-len=20 location=/tmp/output.png -vvv
> splitter.

 You don't need a typefind in your pipeline.  It fails to find the type of the 
raw video (there's nothing in a raw video stream to indicate what type it is) 
and therefore it doesn't negotiate its caps with the pngenc.

 To debug a pipeline, it's convenient to strip it down until something works, 
that way you can find out which element causes the problem.  You can replace 
a video source with videotestsrc and the sink with fakesink.  That way, 
you'll find out that

 videotestsrc ! typefind ! pngenc snapshot=false ! fakesink

doesn't work, while

 videotestsrc ! pngenc snapshot=false ! fakesink

does work.

 Regards,
 Arnout
-- 
Arnout Vandecappelle                               arnout at mind be
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