How to format a IMediaSample?

[Maarten Lankhorst]

I'm having troubles sending a media sample over the graph,
I'm wondering wether that is because of the receiving filter or my own 
fault.

the thing I'm trying to send is a uncompressed 24 bit image, the bitmap 
info header data of it is pretty much as this:

mediatype: BI_RGB24
Width: 320
Height: 240
Bitcount: 24
Size of the image in bytes: 230400
compression: BI_RGB

so my questions about it are:
- What should I do with the ALLOCATOR_PROPERTIES
- What do I have to put in IMediaSample SetActualDataLength
- How can I fill the pointer returned by IMediaSample GetPointer so that 
the sample gets accepted?