[opendtv] Re: Print Story: European broadcasters focus on improved TV picture on Yahoo! New
- From: Bob Miller <bob@xxxxxxxxxx>
- To: opendtv@xxxxxxxxxxxxx
- Date: Tue, 07 Jun 2005 15:39:35 -0400
Manfredi, Albert E wrote:
>John Shutt wrote:
>
>
>
>>You don't think that multicasting is a reality in the US?
>>
>>
>
>I do think it is, or should be. All I'm saying is that your
>idea that HD broadcasts in Europe will save bandwidth is
>not entirely valid. Normally, they won't. Because they will
>normally have to be accompanied by an SD simulcast in
>MPEG-2.
>
>Sometimes they might, though, as in a separate HD stream
>only meant as a premium pay service, for instance.
>
>
>
>>Besides, an MPEG2 SD program and an MPEG4 HD program is
>>more efficient than a single MPEG2 HD program, bitwise.
>>
>>
>
>The original test results of AVC compared with MPEG-2 say
>otherwise. The bit reduction achieved with AVC ranged
>from twice as efficient (half the bit rate) to only 50
>percent better, depending on a bunch of things. So the
>most believable estimate of total bit rate for a
>simulcast is that it's about the same as a single MPEG-2
>HD stream.
>
>Here's a SWAG for you.
>
>For normal 24 fps shows, in ATSC you need avg 10 Mb/s.
>A simulcast would mean ~5 Mb/s SD + 5 Mb/s HD AVC. Of
>course, this can be tweaked down, both in MPEG-2 and in
>AVC.
>
>For 60 fps HD, you need some 16-18 Mb/s in ATSC. A
>simulcast would require still 5 Mb/s in SD and maybe
>9-12 Mb/s in AVC. So not a big difference.
>
>I know the trade press has steadily been inflating the
>improvements you get with AVC. In any case, there's
>nothing but paper and ink keeping AVC from ATSC, at this
>point. (And the transition, which DVB-T has to deal with
>too.)
>
>Bert
>
>
The comparison of MPEG2 and MPEG4 is not static. MPEG4 has a lot of room
for improvement while MPEG2 is near the end of its road. So when talking
futures you have to factor in what MPEG4 will become not just what it is
now.
Paper and ink and all those MPEG2 receivers. A lot fewer receivers were
the excuse not to allow COFDM five years ago. How would we transition to
MPEG4 now? For the required SD program offering that is.
One poster on AVSForum is thinking today. Scowl says...
"My guess is by 2009, stations will want to end broadcasting in this
ancient ATSC MPEG-2 standard and switch to something more bandwidth
efficient. They won't want to lose their digital viewership of course
so... they'll ask for a third channel."
Now that makes sense.
Bob Miller
----------------------------------------------------------------------
You can UNSUBSCRIBE from the OpenDTV list in two ways:
- Using the UNSUBSCRIBE command in your user configuration settings at
FreeLists.org
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word
unsubscribe in the subject line.
Other related posts:
