nanog mailing list archives

Re: [Nanog] ATT VP: Internet to hit capacity by 2010


From: Ric Messier <kilroy () WasHere COM>
Date: Mon, 21 Apr 2008 20:25:07 +0000 (UTC)


On Mon, 21 Apr 2008, Chris Adams wrote:


Nope, ATSC is 19 (more accurately 19.28) megabits per second.  That can
carry multiple sub-channels, or it can be used for a single channel.
Standard definition DVDs can be up to 10 megabits per second.  Both only
use MPEG2; MPEG4 can be around half that for similar quality.  The base
Blu-Ray data rate is 36 megabits per second (to allow for high quality
MPEG2 at up to 1080p60 resolution).


From wikipedia (see: Appeal to authority :-):
The different resolutions can operate in progressive scan or interlaced 
mode, although the highest 1080-line system cannot display progressive 
images at the rate of 59.94 or 60 frames per second. (Such technology was 
seen as too advanced at the time, plus the image quality was deemed to be 
too poor considering the amount of data that can be transmitted.) A 
terrestrial (over-the-air) transmission carries 19.39 megabits of data per 
second, compared to a maximum possible bitrate of 10.08 Mbit/s allowed in 
the DVD standard.


Ric


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