Need clarification on gstcolorbalance

[Yogesh Marwaha]

On 20 May 2012 16:38, Tim-Philipp Müller <t.i.m at zen.co.uk> wrote:
> On Sun, 2012-05-20 at 13:17 +0530, Yogesh Marwaha wrote:
>> Hi,
>>
>> I'm trying to add options of contrast, brightness etc. in my app.
>> GStreamer's videobalance and xvimagesink elements support
>> GstColorBalance interface. But in case of xvimagesink, I'm unable
>> to get a list of channels.
>>
>> Following is the code snippet I'm using: -
>>
>>     GstElement *a = gst_element_factory_make("xvimagesink",
>> "gravity-playbin-video-a");
>>     if(GST_IS_COLOR_BALANCE(a)){
>>  (...)
>> What could be the cause of problem? How should I do it properly?
>
> Try adding a
>
>  gst_element_set_state (a, GST_STATE_READY);
>
> right after creating it.

Now I get the following:-
Channel name: XV_BRIGHTNESS
Channel name: XV_CONTRAST

I was also expecting HUE and SATURATION to be listed.

Anyways, my main problem is that values of these properties provided
by xvimagesink & videobalance elements are imcompatiable, so I was
searching for a standard way of setting their values so that I may use
same code, no matter I'm using xvimagesink or videobalance+ximagesink.

What do you recommend? Would I have to/(Should I) use separate code
for both cases? Or do I forget that xvimagesink offers these
properties?

PS: Upto now I had been thinking that standard property names in
gstreamer (e.g. the volume property) imply standard values, and all my
code also assumes that.

Regards,

Yogesh Marwaha