[opendtv] Re: Frames Per Second of 720P

  • From: "John Willkie" <johnwillkie@xxxxxxxxxxxxx>
  • To: <opendtv@xxxxxxxxxxxxx>
  • Date: Sun, 27 Jul 2008 19:13:11 -0700


So, now you think that the content should be formatted differently for
mobile/handheld, but you want that content to be made available on
television sets in homes. Obviously, intellectual consistency is not one of
your attributes.

Also, I think it's unlikely that broadcasters devoted to HDTV will engage in
much M/H broadcasting, unless they are showing mostly talking heads in HDTV.
There just isn't much headroom.

So, they won't bite into HDTV or SDTV stream bit rates; there will just be
fewer null packets. Some streams I have seen have more than 50% null

The demos at NAB showed that the two systems shown used good, old fashioned
UDP/IP multicasting.  So, to put that -- without prejudice towards what the
ATSC releases -- into your television set would be something basically
beyond the ken of traditional television sets.

I can say that the A-VSB proposal involves many levels of decoding
complexity, and quite a few dedicated circuits.  Last time I checked,
television sets had just the circuitry they need.  They aren't future-proof.

"Potentially be delivered in PIP" isn't a realistic target, of course, since
few receivers have this functionality.  So, small screen formatting "will
still work" is a non starter.  Broadcasters want mass audiences, not
specialized niche audiences.

Wow, robust 240x320 video.  What an absurd idea for homes; even pcs have
better video than that.

What you need to consider is simply this:  what if the business and
technical models for M/H are totally unique and unprecedented, with little
or no regard for what has come before?  What if it goes beyond the technical
and business models used in any form of DVB, ISDB-T, and other forms of
digital broadcasting?  What if it isn't really broadcasting at all, and what
if it actually -- or mostly -- provides a way to transmit non-real-time
television (or non-television) programming?

What if some broadcasters devote all or most of their M/H stream or streams
to downloadable content?  What if other broadcasters use their M/H streams
to send Usenet or You Tube content?  How would your television set make use
of an image encapsulated in a MIME wrapper?

Everything you have been talking about is basically putting new lipstick on
the pig.  What if M/H is an agile antelope with no makeup?  

What if M/H is mostly a rich authoring environment for transmitting traffic
updates?  What if M/H requires a "back channel" of some type for user
interaction?  What if M/H is something that only cell carriers, or MediaFlo
can transmit?  What if M/H works with those types of services, and
broadcast, and web-based streaming media?  What if all of the above is true?
What if none of the above is true?  What if only part is true?  What if
tentative decisions of the various M/H subcommittees are ripped up at the
last minute for something completely different?  What if the candidate
standard is rejected and doesn't become a published standard?  What if M/H
encoders are too difficult for the average PhD to operate, and the receivers
are too difficult to implement?  What if the modulation system wasn't tested
properly, or isn't improved or denigrated enough to satisfy the ATSC?  What
if the ATSC had nothing or little to do with the selection of the modulation
system?  What if M/H video quality and frame rate ranks with that of a
mechanical Etch-a-Sketch?

I've mentioned the concept of an electronic service guide.  What if that
barely has any relationship to the electronic program guides that we have

It's possible that blue is equal to red, so talking about possibilities
isn't real discussing.  

I'm not guessing as to many of the questions above, Bert.  You are entirely
guessing, and with little thinking, to boot.

John Willkie

-----Mensaje original-----
De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En
nombre de Albert Manfredi
Enviado el: Sunday, July 27, 2008 6:40 PM
Para: opendtv@xxxxxxxxxxxxx
Asunto: [opendtv] Re: Frames Per Second of 720P

Tom Barry wrote:

> The net result is I really do want things framed differently
> between my phone and front projector.

I don't doubt that streams meant for mobile hand-held devices would be
formatted differently than programs optimized for typical fixed receivers.
That seems so drop-dead obvious as to be uninteresting to dwell over,

First of all, it's still possible that broadcasters want that content to
also be available to their fixed receiver viewers. Is there a down side to
the broadcaster? If the broadcaster is going to bite into his SD and HD bit
stream anyway to provide M/H service, it's absurd to think that making this
also available to fixed receivers somehow makes the penalty worse.

Secondly, that content could potentially be delivered in a PIP display of
the fixed receiver, so the small screen formatting could still work.

Most importantly, though, if fixed receivers have the M/H demod, they could
make use of the robust stream capability for times like John Shutt mentioned
in the past. Example, if transmitter power has to be reduced for
maintenance. Presumably, the broadcaster wants to retain his coverage area
in these cases?

To me, an extra tool in the OTA broadcaster's tool chest should be used as
effectively as possible. Besides which, chip vendors will probably soon
incorporate the M/H demod in all their ATSC chips, at which time the cost
difference to fixed receivers will be minimal.


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