SetPointer method sets the pointer to the memory buffer.
Pointer to a memory buffer allocated by the caller, of size cBytes.
Length of the buffer, in bytes.
This method enables the allocator to set a new pointer for the sample.
This method is not available through the IMediaSample interface. The object that creates the sample can access this method (through CMediaSample), but other objects cannot.
Build date: 11/16/2013