[gst-devel] using the tuner interface from python

[thiagoss]

On Wed, Sep 30, 2009 at 2:52 PM, thiagoss <thiagossantos at gmail.com> wrote:

>
>
> On Wed, Sep 30, 2009 at 1:17 PM, Dick Marinus <dick at mrns.nl> wrote:
>
>> Hi all,
>>
>> At April 30, 2006 Fredrik posted a message about using the tuner
>> interface from Python and I'm experiencing the same issue:
>>
>> $ python
>> >>> import gst
>> >>> source = gst.element_factory_make("v4l2src",name="Pinnacle PCTV
>> USB2.0")
>> >>> print source.get_channel()
>>
>> (.:13363): GStreamer-CRITICAL **: gst_implements_interface_cast:
>> assertion `gst_element_implements_interface (GST_ELEMENT (from),
>> iface_type)' failed
>>
>> ** (.:13363): CRITICAL **: gst_tuner_get_channel: assertion
>> `GST_IS_TUNER (tuner)' failed
>>
>> I've tried to set the pipeline queue to STATE_PLAYING but I still have
>> the same error.
>>
>> I guess something is broken at the Python bindings. Could someone please
>> help me?
>>
>
> I had this same problem this week on a toy project and thaytan sent me a
> python script that uses GstTuner interface from v4l2src, but I still haven't
> looked deeply at it. I'll do it tonight and I'll update here with my
> findings.
>
> One thing I noticed, though, is that GstV4l2Src is using a subclass of
> GstTunerChannel that is not mapped/exported in the python bindings (but I
> don't know much about bindings and thaytan said it worked for him, so I
> believe I'm doing something wrong in my code).
>
>
Found what was wrong:

1) It will not work on NULL state, I don't know if works on READY, tested
only with it PLAYING and I'm assuming it also works for PAUSED

2) You're not supposed to create your own gst.TunerChannel objects and set
them, you have to do src.list_channels() and pick one to set.

Works perfectly here. Maybe the docs could be updated to clarify this.


>
>
>>
>> I'm using:
>> gst-python=0.10.16
>> gstreamer=0.10.24
>> gst-plugins-good=0.10.16
>> gst-plugins-base=0.10.24
>>
>> Thanks in advance,
>> Dick
>>
>>
>>
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>
>
>
> --
> Thiago Sousa Santos
>



-- 
Thiago Sousa Santos
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