[MPlayer-dev-eng] Packed YUV -> RGB Conversion; Speed Freak

[Mike Melanson]

Hi team,
	Look out, I've been RTFS'ing again, and now I have more 
questions. I recently discovered the postprocessing unit. After studying
it for awhile, it occurred to me that the yuv2rgb module is strictly 
YV12->RGB. Some modules hack the input to allow I420/IYUV data, but the
converter only handles planar YUV data. But there aren't any converters
for packed YUV formats -> RGB, correct? I might take a stab at writing one
if no one else is interested.

	Speed freak question: I've recently come to understand that when
outputting BGR32 data, it's useful to transfer full 32-bit pixels, rather
than 4 individual bytes. In rendering BGR24 data, would it be plausible
to have pre-rendered pixel values as 32-bit integers and then transfer
them to the output image, but only advance the pixel pointer by 3 bytes
each time? Like so:

  unsigned char *out_ptr;
  unsigned int pixel1, pixel2;
  (unsigned int *)out_ptr = pixel1;
  out_ptr += 3;
  (unsigned int *)out_ptr = pixel2;

Or would this net a performance hit because of not transferring data on
neat 32-bit memory boundaries? No big deal, just curious.

	Thanks...
-- 
	-Mike Melanson