[gst-devel] Two v4lsrc related problems

[David Schleef]

On Thu, Apr 01, 2004 at 11:12:01PM +0200, Thomas Kuleßa wrote:
> 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.

This is normal, as some elements only support certain colorspaces.
In particular, the effectv elements all require 32-bit RGB.
videocrop and videobalance only support I420.  Adding
ffmpegcolorspace between elements helps.



dave...