G200+NV12 (Re: [MPlayer-G2-dev] Darwin port)

[D Richard Felker III]

On Fri, May 09, 2003 at 01:32:22AM +0200, Arpi wrote:
> Btw Vektor mentioned scanline buffers yesterday, and I think it's a very
> interesting approach. ie. replace plane+stride with array of scanline
> pointers :)
> It would allow very amazing optimizations, like DR scanlines without OSD,
> and copy the rest. But I guess such feature won't go into g2 soon, maybe
> into g3, or in g2 v2.0 :))

Yes, but it's only good for scanline-based filters. For example, if
you want to apply a block-based filter (e.g. deblock, dering, telecine
detection, anything DCT-based, etc.) you have to load a separate base
pointer every 8 pixels or so inside your inner loop, which is horribly
inefficient. With a single base plus stride, you can just use two
registers (current position and stride) with no extra memory reads.

Rich