[gst-devel] Two v4lsrc related problems

Thomas Kuleßa thomas.kulessa at epost.de
Thu Apr 1 13:13:02 CEST 2004

Hi again

Am Do, den 01.04.2004 schrieb Ronald Bultje um 17:33:
> > 2. Another problem I encountered just yesterday is that the pipe
> > "videotestsrc ! myfilter ! xvimagesink" works as it is supposed, but
> > "v4lsrc ! myfilter ! xvimagesink" results in a broken image. Perhaps it
> > has something to do with incorrect image dimensions/formats during
> > tramsformation.
> > Obviously the error is in myfilter, but in both cases its inputs,
> > outputs are YUV2 buffers.
> I cannot reproduce this, filters work fine for me... Can you provide
> source for the filter?

I explored this issue a bit more an found out, that several, if not all of the standard filter plugins, do
not work with the v4lsrc. With the videotestsrc they work fine.
I tried 
gstreamer-launch-0.8 v4lsrc device=/dev/video0 ! <filter> ! x(v)image,
wheras <filter> was videocrop, videobalance, edgeTV, agingTV and others.
E.g. v4lsrc ! videobalance !  xvimagesink results in a broken image with the occasional
error message: 
ERROR: from element /pipeline0/v4lsrc0: Could not synchronize on resource.
Additional debug info:
v4lsrc_calls.c(119): gst_v4lsrc_sync_frame: /pipeline0/v4lsrc0:
system error: input-/outputerror

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