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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: [Nanog] ATT VP: Internet to hit capacity by 2010
On Apr 21, 2008, at 9:35 PM, Frank Bulk - iNAME wrote: > I've found it interesting that those who do Internet TV (re)define > HD in a > way that no one would consider HD anymore except the provider. =) > The FCC did not appear to set a bit rate specification for HD Television. The ATSC standard (A-53 part 4) specifies aspect ratios and pixel formats and frame rates, but not bit rates. So AFAICT, no redefinition is necessary. If you are doing (say) 720 x 1280 at 30 fps, you can call it HD, regardless of your bit rate. If you can find somewhere where the standard says otherwise, I would like to know about it. > In the news recently has been some complaints about Comcast's HD TV. > Comcast has been (selectively) fitting 3 MPEG-2 HD streams in a 6 MHz > carrier (38 Mbps = 12.6 Mbps) and customers aren't happy with that. > I'm not > sure how the average consumer will see 1.5 Mbps for HD video as > sufficient > unless it's QVGA. Well, not with a 15+ year old standard like MPEG-2. (And, of course, HD is a set of pixel formats that specifically does not include QVGA.) I have had video professionals go "wow" at H.264 dual pass 720 p encodings at 2 Mbps, so it can be done. The real question is, how often do you see artifacts ? And, how much does the user care ? Modern encodings at these bit rates tend to provide very good encodings of static scenes. As the on-screen action increases, so does the likelihood of artifacts, so selection of bit rate depends I think on user expectations and the typical content being down. (As an aside, I see lots of artifacts on my at-home Cable HD, but I don't know their bandwidth allocation.) Regards Marshall > > > Frank > > -----Original Message----- > From: Alex Thurlow [mailto:[email protected]] > Sent: Monday, April 21, 2008 4:26 PM > To: [email protected] > Subject: Re: [Nanog] ATT VP: Internet to hit capacity by 2010 > > <snip> > > 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 > [email protected] > http://mailman.nanog.org/mailman/listinfo/nanog > > > _______________________________________________ > NANOG mailing list > [email protected] > http://mailman.nanog.org/mailman/listinfo/nanog _______________________________________________ NANOG mailing list [email protected] http://mailman.nanog.org/mailman/listinfo/nanog
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