Bug#696727: cheese does not start with Gtk-Warning

[Emilio Pozuelo Monfort]

On 03/28/2013 03:26 PM, Jonathan Dowland wrote:
> On Thu, Mar 28, 2013 at 10:21:30AM +0000, Jonathan Dowland wrote:
>> UI ("No device found"). Interesting stuff. I'm going to try splicing some
>> debug statements into the code to see at what point it reaches and whether
>> that helps get any further.
> 
> I've poked around a little, attached is a backtrace taken when interrupting the
> spinning process. It shows the last routine executed in cheese code as
> cheese_camera_play. Poking around in the C, 
> 
> cheese_camera_play (CheeseCamera *camera)
> {
>   …
>     gst_element_set_state (priv->camerabin, GST_STATE_PLAYING);
> 
>     ^^
> 
> That's as far as cheese gets. So, is this a gstreamer bug? (or
> gstreamer0.10-plugins-bad)? Seems it uses 'camerabin', which has been
> deprecated in favour of 'camerabin2' in gst 0.10, and dropped by 1.0.
> Cheese moved to camerabin2 between 3.5.5 and 3.5.091.
> 

Most likely not a cheese bug; you can confirm that by trying e.g. empathy, which
will probably fail to use the webcam too. After that I'd try with another tool
that doesn't use gstreamer, then we can pinpoint whether this is a gstreamer bug
or not.

I remember from when I did video integration in empathy that some webcams will
only work once, and after that you have to unload the kernel module and load it
again for them to work. If that was the case here, the problem could be that
cheese is not stopping them properly.

Regards,
Emilio