|
yes it is zero typically where the media type is 24 bits per pixel, and the whole frame work supports systems that can only access a full word. At the pixel level it is the 'quad'. at the pixel row level it is the 'image stride'.
'reserved' was 'reserved' for any 32bit pixel type even where the reserved byte data does not translate to visual 'alpha'
The 'reserved' byte could hold any data related to the pixel.
The 'must be zero' key 'must be zero' where you are only sending 24bits of color to a machine that it is unknown what Endian it is. Your RGBQuads are handled in the same system, and only to shuffle the pointed values. Clearly your render pipeline requests ARGB pixels, which are 32bits packed. You can create your own class handler to handle the pointers.
You should also look at the 32bit alpha media type from the directshow samples.
|