[gst-devel] About using the tuner interface in python

[Fredrik Persson]

Hi!

If programming in c, it seems that I can get a cast from source element to 
tuner like this: 

tuner = GST_TUNER (video_source);

This seems to be needed in order to use the list_channels, get_channel and 
set_channel methods that selects inputs (composite, S-video and so on) on 
capture cards.

Does anyone know what the equivalent would be in python? At first I thought 
that these methods could be used on a v4l2src element like so:

source = gst.element_factory_make("v4l2src",name="Pinnacle PCTV USB2.0")
print source.get_channel()

This does not work. I get the following error message when running that:

(mypythontest.py:21507): GStreamer-CRITICAL **: gst_implements_interface_cast: 
assertion `gst_element_implements_interface (GST_ELEMENT (from), iface_type)' 
failed
Segmentation fault

So my question is, how do I select the composite input on my capture card 
using gstreamer and python?

Thank you!

/Fredrik Persson