callback method and ISampleGrabber 
Author Message
 callback method and ISampleGrabber


I need an app to capture still images from a media using
DirectX and VB.
As the sdk's say I'm using ISampleGrabber and

I'm trying with the callback method. Same part of my code
is like this,

   m_objSampleGrabber.SetOneShot False
   m_objSampleGrabber.SetBufferSamples True

   Set m_objSampleGrabberCB = New CGrabCB

   ' 0 -> SampleCB
   m_objSampleGrabber.SetCallback  m_objSampleGrabberCB, 0

where m_objSampleGrabber is a ISampleGrabber and
m_objSampleGrabberCB is an object of my
class, CGrabCB, that inherits from ISampleGrabberCB.

The problem is that in the inherit method
ISampleGrabberCB_SampleCB of this class I can't access to
the method GetPointer of the IMediaSample Interface, I
think that this method give me a pointer to the still,
sample, image in memory. The message is as follow:

   Compile error:

   Function or inteface marked as restricted, or the
funtion uses and Automatation type not supported in Visual

What am I doing wrong? Is not possible to use callback
method from VB?

Thanks in advance.

Tue, 07 Dec 2004 16:57:19 GMT  
 [ 1 post ] 

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