[gst-devel] v4l2src GstTuner interface

[Stefan Kost]

hi julien,

Julien Isorce schrieb:
> Hi,
> 
> I am trying to select physical input (S-Video, Composite, ...)
> 
> The following code :
> 
> ------------
> ...
> videodevicesrc = gst_element_factory_make("v4l2src", "videodevicesrc");
> ...
> GstTuner *tuner = GST_TUNER (videodevicesrc);
> ...
> ------------
> 
> leads to:
> 
> (<unknown>:17146): GStreamer-CRITICAL **: gst_implements_interface_cast: 
> assertion `gst_element_implements_interface (GST_ELEMENT (from), 
> iface_type)' failed


You can only cast in PAUSED or PLAYING (not sure about READY). Basically the 
devices has to be opened first, before the element knows that the underlying 
hardware has support for tuner. The gst_implements_interface mechanism is 
basically a hack to conditinally implement interfaces.

Stefan

> 
> 
> I know that v4l2src implements this interface and
> I got code example from 
> http://webcvs.freedesktop.org/gstreamer/gst-plugins-good/tests/icles/v4l2src-test.c?revision=1.1&view=markup 
> <http://webcvs.freedesktop.org/gstreamer/gst-plugins-good/tests/icles/v4l2src-test.c?revision=1.1&view=markup>
> 
> The installed packages is 
> gstreamer0.10-plugins-good_0.10.6-0ubuntu4_i386.deb
> 
> The following command lien works very fine : gst-launch-0.10 v4l2src ! 
> xvimagesink
> 
> Where am I wrong ?
> 
> Sincerely
> 
> Julien
> 
> 
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