Camerabin - how to specify size of image for capture

Thiago Santos thiago.sousa.santos at
Mon Feb 24 06:18:28 PST 2014

On 02/24/2014 10:57 AM, Ian Davidson wrote:
> I looked around at whatever I could find, and discovered the file 
> gst-camerabin2-test.c.  In there, it appeared that it was setting the 
> caps to "video/x-raw-yuv" - so I thought I would try that in my 
> program to see if it would make a difference.
> It did make a difference - although not too helpful.
> If I leave the setting to video/x-raw, the program crashes with the 
> 'not-negotiated'.
Please don't use the word 'crash' if what you see is not a crash 
(segfault or similar). It seems that you are seeing
a gstreamer error. Are you sure you are using a supported resolution for 
your video input?

> With the setting "video/x-raw-yuv", my program allows me to attempt to 
> take a photo, but then reports:
> GLib-GObject-WARNING ** : invalid (NULL) pointer instance
> GLib-GObject-CRITICAL**: g_signal_emit_by_name: assertion 
> 'G_TYPE_CHECK_NSTANCE (instance)' failed
> Examining the logs shows that it seems to have been able to negotiate 
> successfully - but then it does not result in a captured image.

Sorry for that, the example was using the old 0.10 raw caps notation. In 
1.x series you should use video/x-raw over video/x-raw-yuv
or video/x-raw-rgb. I just updated the example to fix that.


> Ian
> On 20/02/2014 14:37, Tim Müller wrote:
>> On Thu, 2014-02-20 at 14:21 +0000, Ian Davidson wrote:
>>> It crashed when I tried to establish an image size of 800x600.
>> It errors out with not-negotiated it seems, which indicates a problem
>> with the caps negotiation.
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