[Open-graphics] RGB/YUV converstion... importance?

[Timothy Miller]

On 9/8/06, Attila Kinali <attila at kinali.ch> wrote:

> Also an issue here is the subsampling, ie that the U and V
> planes are down scaled by a factor two in the width (4:2:2)
> or in widht and height (4:2:0). This scaling has to be
> inverted before YUV->RGB conversion.
>
> Though uncommon, it might be a good idea if strange
> subsampling formats (like those seen with DV files)
> could be supported too (using a 2/3 down scaling and
> stuff like that)

Converting YUV to RGB is computationally expensive, but splicing bytes
together is not.  We can support formats like xYUV and YUYV, but when
it comes to more exotic formats (like where U and V are supplied only
for alternating lines), we'll need some help from software.

This converter is one of those things that could end up on the
chopping block if it's too expensive to fit in the ASIC.  Even so,
people will still be able to play video... just with more CPU
overhead.