[opendtv] Re: Finally anamorphically compressed 480i

  • From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
  • To: "opendtv@xxxxxxxxxxxxx" <opendtv@xxxxxxxxxxxxx>
  • Date: Mon, 24 Jan 2011 15:48:19 -0600

John Shutt wrote:

>>> By contrast, legacy letterboxed SD material is upconverted by
>>> PBS to a full screen 1080i30 frame, and AFD coded to letterbox
>>> upon downconversion to SD 4:3.
>>
>> Right. But wow, this is simply wrong! If PBS goes to the trouble
>> of making this great upconverted full screen 16:9 image stream,

> You mean that great upconverted and pillarboxed 4:3?

Sorry, I thought you meant "full screen" 16:9, since it was in the 16:9 HD 
container. If it was letterboxed, it must have been legacy 16:9 SD material. If 
PBS distributes this to stations as upconverted to HD, heaven only knows why 
they don't just deliver it as full 16:9 upconverted to HD, no pillars, no 
letterboxing.

I see some PBS HD programs that do not appear to be true HD quality. I always 
assumed they were upconverted to HD as well, but transmitted as 16:9 and not 
postage stamp. That's how all newer SD programming ought to be delivered to 
stations IMO, and then the stations can forward to us as HD or widescreen SD.

> If we did things the way you suggested, then all full screen SD
> material would lose 25% of their horizontal resolution, and full
> screen still makes up the majority of SD legacy programming.

You're right, it would, but it's actually hard to tell. Vertical res stays 480, 
so that may be part of the reason. By contrast, it is very easy to see loss of 
image quality when zooming in on a postage stamp image.

When you say, "full screen still makes up the majority of SD legacy 
programming," you're not even saying how bad it really is (or seems to be, to 
this consumer). So-called "full screen" (meaning 4:3) makes up the vast 
majority of all SD programming, period. Even ads. I cannot for the life of me 
understand why ANY SD material since 1998 would be/have been shot as 4:3, other 
than in cases where some sort of historical nostalgia was being sought after. 
Honestly, once prime time content went to HD 16:9, and that content was 
obviously headed still to many 4:3 screens, any rationale for shooting SD only 
as 4:3 should have vanished. And certainly today there's no excuse for ever 
transmitting down-converted HD programs as SD 4:3. Yet, it's done all the time.

Perhaps transmitting everything SD as wide screen 704 X 480, with pillars only 
when necessary, would put an end to the practice of gratuitously turning 
anything SD into 4:3? From what you say, it sounds like cable-only channels 
fare no better in this.

> Now, if my television would respond to the AFD codes being broadcast,
> it would automatically zoom for letterboxed material, and pillarbox
> 4:3 material. But it doesn't know that AFD exists.

Maybe a mixed bag, though. How does AFD handle subtitles or off-center postage 
stamps? There's no substitute for just "doing it right."

Bert
 
 
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