[geeks] Whee! Lightning strikes, AGAIN!

Joshua Boyd jdboyd at jdboyd.net
Wed Jul 29 09:22:17 CDT 2009


On Wed, Jul 29, 2009 at 10:18:32AM -0400, Lionel Peterson wrote:
> On Wed, Jul 29, 2009 at 10:12 AM, <gsm at mendelson.com> wrote:
> > On Wed, Jul 29, 2009 at 10:04:22AM -0400, Lionel Peterson wrote:
> >
> >> I guess 1920 x 1080 x 3 (Red, Green, and Blue bytes) x 60 (FPS) - 373
> >> Megabytes/second, but there is no way I'm pulling that data rate out
> >> of my Blu-Ray DVD player, or even half that for "normal" 30 FPS HDTV.
> >
> > Is Blu-Ray RGB? Regular DVDs (and all MPEG type encoding) are digital
> > representations of analog video (luminance and chroma).
> 
> I dunno, but even luminance and chroma would occupy at least a byte
> each, right? Maybe two?

Not quite.  The chroma sampling is often reduced, so while each pixel
has its own luma sample, adjacent pixels may share chroma samples.
4:2:2, which is NTSC, uses half the chroma samples.  4:1:1 and 4:2:0 use
1/4th the chroma samples.



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