C++/VB - Question on IKSPropertySet Interface parameters

Asked By Christian D.

30-Jul-08 03:58 AM

Hi,

I'm a beginner to DirectShow and have some understanding problems with the
IKsPropertySet.

Can someone explain me the difference of the pInstanceData and pPropData in
the IKsPropertySet::Set and IKsPropertySet::Get methodes?
The SDK is 'from a beginners point of view' not very easy to understand.
And the examples in the SDK also do not help here.

From my understanding the pPropData is the data itself send or received
to/from the property set, but what is the instace here? And to what object
does the pointer show? Is it the same as for the pPropData?

Can someone give me some hints or links to further documentaion or some
good code examples that can clearify this.

Thanks for any help
Christian

30-Jul-08 06:47 AM

From: "Christian D."


Think of a property as (in pseudo code):

property <value> <name>();


Unless otherwise documented for a specific property <name>,
the  is empty {NULL,0}, as shown in the sample code
for IKsPropertySet::Get().


--
// Alessandro Angeli
// MVP :: DirectShow / MediaFoundation
// mvpnews at riseoftheants dot com
// http://www.riseoftheants.com/mmx/faq.htm

30-Jul-08 10:01 AM

From "Alessandro Angeli"

Ahh, now thinks become clearer ;)

Do you know any example or scenario where the  is used?
I would like to get a 'bigger picture' of it.

30-Jul-08 10:17 AM

From: "Christian D."


I have never seen any property that uses it.


--
// Alessandro Angeli
// MVP :: DirectShow / MediaFoundation
// mvpnews at riseoftheants dot com
// http://www.riseoftheants.com/mmx/faq.htm

31-Jul-08 02:53 AM

In fact, if you look at IKsControl::KsProperty, which is the interface I
usually use to talk to my AVStream filters, it doesn't even have the
--
Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

31-Jul-08 04:15 AM

From "Tim Roberts":


This is even interesting to know. Thanks for pointing me on that.
Thanks to both of you Allesandro and Tim, to bring some light into the dark
;)

Christian