Chris Adams wrote:
Once upon a time, Steve Gibbard <scg@gibbard.org> said:
iTunes video, which looks perfectly acceptable on my old NTSC TV, is .75 gigabytes per viewable hour. I think HDTV is somewhere around 8 megabits per second (if I'm remembering correctly; I may be wrong about that), which would translate to one megabyte per second, or 3.6 gigabytes per hour.
You're a little low. ATSC (the over-the-air digital broadcast format) is 19 megabits per second or 8.55 gigabytes per hour. My TiVo probably records 12-20 hours per day (I don't watch all that of course), often using two tuners (so up to 38 megabits per second). That's not all HD today of course, but the percentage that is HD is going up.
1.1 terabytes of ATSC-level HD would be a little over 4 hours a day. If you have a family with multiple TVs, that's easy to hit.
That also assumes that we get 40-60 megabit connections (2-3 ATSC format channels) that can sustain that level of traffic to the household with widespread deployment in 2 years and that the "average" household hooks it up to their TVs.
I'm going to have to say that that's much higher than we're actually going to see. You have to remember that there's not a ton of compression going on in that. We're looking to start pushing HD video online, and our intial tests show that 1.5Mbps is plenty to push HD resolutions of video online. We won't necessarily be doing 60 fps or full quality audio, but "HD" doesn't actually define exactly what it's going to be. Look at the HD offerings online today and I think you'll find that they're mostly 1-1.5 Mbps. TV will stay much higher quality than that, but if people are watching from their PCs, I think you'll see much more compression going on, given that the hardware processing it has a lot more horsepower. -- Alex Thurlow Technical Director Blastro Networks _______________________________________________ NANOG mailing list NANOG@nanog.org http://mailman.nanog.org/mailman/listinfo/nanog