[geeks] Whee! Lightning strikes, AGAIN!

[Joshua Boyd]

On Wed, Jul 29, 2009 at 10:04:22AM -0400, Lionel Peterson wrote:
> On Tue, Jul 28, 2009 at 4:39 PM, Joshua Boyd<jdboyd at jdboyd.net> wrote:
> <snip>
> 
> > How is FW800 faster or more reliable at moving the 355 megabytes per
> > second to display a 1920x1080 8 bit RGB image at 59.97 frames per second
> > on a LCD panel?
> 
> What are you talking about? What has those bandwidth needs? Are you
> talking practical or theoretical?
> 
> 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.

> I'm sure I'm missing something. Compression?

You are not pulling 373 MB/s off the disc, but 373 is probably what is
going up the HDMI cable.  For many users, it is probably 187 MB/s, since
they are using 1080i instead of 1080p. 

The difference is that the discs contents are heavily compressed, but
the cable connecting the player to the TV is uncompressed.  If we
standardized on a compressed cable, then everything that doesn't use
that compression method would have to decompress and recompress, which
is the problem with firewire as an interconnect.  Firewire does show up
as an output format on several playback devices, but I've never seen a
TV that would accept that, or anything that would accept it, except for
some of the old DVHS decks.