Baten Kaitos allocates its XFBs from a tagged heap
structure. With the old calculation, too many lines
were being written so the tag of the allocation
after the XFB was being corrupted. Fixes crash
mentioned in this comment:
https://code.google.com/p/dolphin-emu/issues/detail?id=7734#c6
When calculating the size of the undisplayed margin in the case where
fbWidth != fbStride for RealXFB for displaying in the output window,
we do not scale by IR - RealXFB is implicitly 1x.
When AIDMA begins, the first thing it does is load the source address
and length into internal registers. It then triggers the AID interrupt.
Some begin the AIDMA process without all the data necessary for the
interrupt callback being set up already - they require a few more cycles
to set it up (the delay between the DMA being set to begin and the
interrupt firing). The value of this delay was approximated by tests on real
hardware.