[gst-devel] GstPolyBin idea and request for comments

Stefan Kost ensonic at hora-obscura.de
Fri Mar 11 08:53:16 CET 2005

Hi Steve,

To use naming was my initial idea too. The problem is that gobject properties 
are class-wide. That would mean whenever an instance needs some more vocies it 
would register another batch of foo_xxx_nnn properties (where nnn is the voice 
number). The instanbces itself would need to track how many voice they actually 
use. As now all inatnce would have these properties.

Still adding a GST_POLYPHONIC_INTERFACE might be a good idea. This can provide 
the methods to request and change the number of voices (and cares about these 

Application which generate a UI need to use such an interface as, the object may 
have properties on which it does no react:
instance A has 5 voices
instance B has 7 voices
In this case instance A has properties like foo_xxx_006 too, but wont use it.
Thus the GUI should not offer them ideally.

Anyway, doing it in this way will be fine for me too. Are there any pitfalls I 
am overseeing?
I am not sure if registering class_properties at a time where there are already 
instance of the class is causing any harm.


Steve Baker wrote:
> A flag for GstController makes sense since many elements might need it,
> however this sounds like a flag just for PolyBin elements which is getting
> a bit specialised.
> Instead of adding another flag just for PolyBin, you could just document
> the naming convention for the properties so the app can introspect what
> each property does, for example:
> foo_global - a global property which acts on all voices
> foo_voice_003 - a property which acts on voice 3 of the PolyBin
> cheers
>>today we've discussed the GstController (next gen dparams) on IRC and
>>decided to
>>add a G_PARAM_SPEC flag to mark gst_element properties as controllable.
>>There is another situation where I would like to add such a flag for.
>>I've written it down at:
>>So I would need a flag like GST_PARAM_POLYPHONIC. I sounds most useful for
>>audio, but I can imagine using it with graphical effects too.
>>Are there any arguments against adding this flag?
>>SF email is sponsored by - The IT Product Guide
>>Read honest & candid reviews on hundreds of IT Products from real users.
>>Discover which products truly live up to the hype. Start reading now.
>>gstreamer-devel mailing list
>>gstreamer-devel at lists.sourceforge.net

More information about the gstreamer-devel mailing list