SDL digest, Vol 1 #738 - 29 msgs

SDL Development
1

Darrel W, do you happen to know what imdc (codec) is utilized
by QuickTime for this ? For some reason I’m needing to use j420 rather than y420.
y420 corresponds to a documented QuickTime constant, kYUV420PixelFormat whereas
I don’t think j420 is any QuickTime constant. Apparenly the j420 has Apple as manufacturer.
If I use y420 though, I get a BAM, KABOOM , BOMB when I go to setup and blit. No such problem
with j420. If you think this too off topic, please respond direct to @Mark_Whittemore

I’m going to compare a sample blitter written direct against QuickTime v.s. SDL based blitter
… for my own sanity to make sure it seems like SDL is not adding
any overhead or is doing as well with QuickTime as you guys claim it should.

Thanks for your respones.

Darrel previously said …---------------------------------------
The above quote is correct. However, the 3D chip is only used if Quartz
Extreme is enabled, otherwise it seems to use the hardware’s 2D
acceleration (AFAIK this works on the ATI Rage Pro, whereas OpenGL does
is unsupported on this card).

This implies that we never have a direct pointer to the hardware
overlay in VRAM. But that’s OK because the YUV data can be DMA’d to
VRAM (with minimal CPU expense). Of course, this means you can only go
as fast as the bus throughput allows (when transferring the entire YUV
surface each time). But that should be insanely fast for most
applications, unless you require enormous resolutions.