I'm in the middle of writing my first avstream-based minidriver, and
have been experimenting with the behaviour of everything. I'm
confused, though, when it comes to the concept of allocator framing.
I gather from the DDK documentation that I should be able to
declare a
KSALLOCATOR_FRAMING_EX struct and point to it in my pin descriptor,
and through it specify what frame sizes my pin's process dispatch can
accept.
DECLARE_SIMPLE_FRAMING_EX(PinFraming,
STATIC_KS_TYPE_DONT_CARE,
KSALLOCATOR_REQUIREMENTF_SYSTEM_MEMORY,
1024, // Frames
FILE_BYTE_ALIGNMENT,
6, // MinFrameSize
6 // MaxFrameSize
);
Now with these requirements specified by my pin, I'd expect to be
given up to 1024 frames, each of 6 bytes in size, in one call to my
process dispatch. What I actually get passed is one frame 8192 bytes
long, clearly beyond the range I specified.
