[opendtv] Re: Frames Per Second of 720P
- From: "John Willkie" <johnwillkie@xxxxxxxxxxxxx>
- To: <opendtv@xxxxxxxxxxxxx>
- Date: Sat, 26 Jul 2008 10:07:17 -0700
There's much I cannot say (but a small amount, compared to what Mark Aitken
cannot say) or refute, due to certain agreements t which I am a party.
I can say that I saw at NAB the booths of Haris' MPH proposal, and that of
Audiovox/MobiTv/Rohde & Schwarz. These were competing proposals. At this
point, it appears that one of those proposals was mostly a winner, and one
of those proposals was mostly a loser. I could draw your attention to the
press conference between LG and Samsung (historically hostile) in Korea in
mid-May.
Harris did show an expanded EPG. But, to the best of my knowledge, there
has been no firm decision made on which ESG will be included in the MH
candidate standard.
I'm really amazed by the lack of leaks on the work of ATSC S4. There are
some pretty amazing things in process, and concentrating on codecs or legacy
receivers is to totally miss the point. At some point in the future, the
candidate standard should be released to the public, and discussion here and
elsewhere can ensue.
It's totally absurd to mention the deprivation of legacy receivers in this
context; it's like asking "how will color cameras affect black and white
television sets?"
Let me give you an example that I can talk freely about. When you shoot for
small screens, you "shoot bigger" than when you shoot for a large screen.
When shooting someone's face, you would tend to make their face fill more of
the screen than if you were shooting for a large, or even room-filling
screen.
So, if you think that there's much utility in showing a screen-filling face
on a large, room-filling tv set, rock on.
I think it's also safe to say that for the most part, MH programming (like
most mobile tv programming) will not be -30 or -60 minute 'traditional' tv
programs but will be in shorter bumps. Fools acting on "behalf' of others
might think that showing movies on 2 or three inch screens is a great thing,
but the subtlety of (all but non-porn) movies is lost on the small screen.
All standards are out of date in this time frame at the time they are
adopted. But that's not the real problem with standards. "I love
standards, there are just too many of them" is the real problem. But,
thankfully, there is only one standard for digital tv transmission in the
U.S.
Back to the ESG (electronic service guide). Wouldn't it be cool if the same
devices all over the world could employ the same bits to render an ESG? If
that ESG would work over the web, over the air, and be usable on WiFi
devices, mobile phones, web browsers, wireless routers, etc. etc., and be
able to provide programming information on broadcasts, regardless of
modulation or channel coding? There is already such an electronic service
guide system, and I could even talk about it without violating the ATSC NDA.
But I won't. "Already" might be an exaggeration, but only by a few weeks or
so.
If you think that 8-VSB is more efficient than a modulation scheme that you
know nothing about, one wonders about your sanity. It seems to me that,
since the payload of any modulation scheme for tv is largely carrying video
(something like 95% or more of a program service is video) that the more
relevant figure is the efficiency of video compression and how that is
packetized. I suspect that you don't mean to imply that MPEG-2 is more
bit-efficient than MPEG-4.
I think that it's unlikely that "new receivers 'may" be able to take
advantage of the new mobile bits to improve their ability to tune to any DTV
channel " The ATSC M/H process had three different modulation/coding
schemes to consider. I know not much about the Thomson proposal, and I
haven't bothered to look it up. I know a bit more about the Harris/LG MPH
proposal, and I know quite a bit about the A-VSB proposal thanks to one R&S
engineer I talked to at NAB that provided me with an 8mb powerpoint
presentation. (And, I've talked with several Samsung consultants over the
years that their proposal has been pending.)
To the best of my knowledge, nothing in these proposals would have aided the
ability to tune into any legacy programming. Indeed, if we are talking
about the early phases of the A-VSB proposal, it would have lessened if not
merely prevented the ability to tune into legacy broadcasts.
Much work is going on behind the curtain. At some point this year, the
curtain will be pulled back. And, I suspect there will be much discussion
here, but discussion of "what's new and cool" won't center on the
modulation, coding or codecs.
I can say that I am truly amazed, at my level of participation, of how most
participants in S4's work have a clear interest in breaking from the past
and not defending legacy concepts.
From what I see today -- and not knowing about the layers of approval before
this stuff becomes public -- ATSC M/H is a "whole new ballgame."
I would also note that just about any improvement in digital modulation or
coding (DVB-H, DVB-T2) doesn't work with well, if at all, with legacy
receivers. So, that ain't an ATSC issue per se.
John Willkie
EtherGuide Systems
-----Mensaje original-----
De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En
nombre de Craig Birkmaier
Enviado el: Saturday, July 26, 2008 5:34 AM
Para: opendtv@xxxxxxxxxxxxx
Asunto: [opendtv] Re: Frames Per Second of 720P
At 12:54 PM -0400 7/24/08, Mark A. Aitken wrote:
>Your last statement flies in the face of reality. What HAS been
>demonstrated, what IS being standardized, is a (relatively) simple
>way to add 'mobile/handheld bits' in a backwards compatible way.
>Nothing breaks. Reallocate bits - some for fixed reception, others
>that can also be received while in motion.
>
>Where did you get the notion that almost everything had to change?
>(we proposed doing that as you well know, but it did not get off the
>ground due to political inertia and mass...and probably a bit of
>shenanigans!)
SORRY. I know that the standard will break nothing. I should have
been more clear.
We were having a discussion about the ATSC standard already being out
of date, particularly with respect to the installed base of ATSC
receivers, which will not be able to access the mobile services.
These new services will likely use h.264 encoding and there will be
new "support infrastructure" for the mobile bits that legacy
receivers will not understand. At NAB Harris was demonstrating a
newer and more capable program guide, than the one that exists in the
current ATSC standard.
So while the new mobile service does not break anything per se', it
requires almost everything else to be updated with technologies that
legacy receivers do not support. Furthermore, some of these new
capabilities would ALSO be useful for legacy broadcasts - like h.264
HD encoding.
THere is little doubt that once the standard for mobile is adopted,
that we may see new fixed location TVs add support for the mobile and
infrastructure enhancements. For example, we could see new TVs with
h.264 and integrated PVRs, which could subscribe to a movie download
service using the more efficient 8-VSB modulation. And new receivers
'may" be able to take advantage of the new mobile bits to improve
their ability to tune to any DTV channel.
So this is not a zero sum game. One could even suggest that this is a
backdoor way to enhance the ATSC standard. It will be interesting to
see what transpires.
Regards
Craig
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