Re: [gst-devel] v4l2sink with USB webcam gadget

[David S. <ds...@en...>]

On Thu, Feb 10, 2011 at 09:15:49AM +0200, Marco Ballesio wrote:
> Hi,
> 
> On Wed, Feb 9, 2011 at 9:17 PM, Will Kelleher <wil...@nu...> wrote:
> > Hi everyone,
> >
> > I've been trying to use my TI Davinci hardware as a USB webcam gadget.
> >  I backported the webcam module to the 2.6.32 kernel and I can
> > compile/load it successfully.  This module creates a v4l2 output
> > device that can accept YUY2 and MJPEG formats.
> >
> > When I run
> >
> > gst-launch videotestsrc ! v4l2sink device=/dev/video1
> >
> > I get
> >
> > "ERROR: from element
> > /GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0: Could not
> > negotiate format"
> 
> probably you need to convert format/resolution/frame rate. If you want
> to know what went wrong with your caps negotiation, use -m as an
> option for gst-launch. If you want even more details, you can set
> GST_DEBUG=GST_CAPS:3 (or more).

You're much better off debugging caps negotiation problems using:

  GST_DEBUG=capsdebug:3 gst-launch videotestsrc ! capsdebug ! v4l2sink



David