FYI: Comcast digital TV in Cambridge

Jarod Wilson jarod-ajLrJawYSntWk0Htik3J/w at public.gmane.org
Thu Dec 4 14:26:47 EST 2008


On Thu, 2008-12-04 at 12:10 -0500, Mark J. Dulcey wrote:
[...]
> Personally, I think the whole HDMI/HDCP thing is silly anyway; it's a 
> prime example of factoring the problem incorrectly. People are busy 
> trying to figure out how to make very high bandwidth wireless links to 
> work so that they can move around uncompressed high-definition video. 
> But since nearly all of the program sources for HD are compressed to 
> begin with (the exception: output from computers and game consoles), why 
> are we trying to do that? The HD decoding should be inside the MONITORS 
> and television sets

Which is of course exactly what they do for clear QAM if you have a set
w/a built-in tuner, so its certainly doable.

> , not the PVRs and DVD and Blu-Ray players; if you do 
> that, existing links like 801.11n would work just fine, let alone future 
> things like UWB. (801.11g would work for 1080i content but be marginal 
> for 1080p.)

Are we talking h.264 here or mpeg2? I can tell you from first-hand
experience, you can NOT stream 1080i mpeg2 hdtv content over 802.11g
with any sort of reliability. Too much packet loss, and while g claims
54Mbps throughput, I've never seen better than a sustained 2.4MB/s
transfer, which is about what most 1080i mpeg2 streams require.

802.11n on the other hand, works quite beautifully for all hdtv content
-- my Mac Mini is now two stories above my n base station, and doesn't
have the greatest signal with the single antenna in the Mini, but it
still plays hdtv recordings off my MythTV backend just fine. Should be
plenty of bandwidth for 1080p h.264 stuff as well, but the cpu in my
Mini can't quite handle the playback demands.

--jarod







More information about the Discuss mailing list