[opendtv] Re: 70th Anniversary Blu-ray and standard DVDs of the Wizard of Oz

  • From: Kilroy Hughes <Kilroy.Hughes@xxxxxxxxxxxxx>
  • To: "opendtv@xxxxxxxxxxxxx" <opendtv@xxxxxxxxxxxxx>
  • Date: Wed, 7 Oct 2009 15:23:41 +0000

I know you share genetic material with TV sets and see the problem as adapting 
different content aspect ratios and frame rates to whatever the most popular 
sets like, but I want to share with you the pain I live in the world of "three 
screens and a cloud".  

In my world, not only is content all over the map, with more combinations of 
picture shape, resolution, and frame rate than broadcast (but thankfully less 
interlace and non-square samples) ... but devices and viewing conditions are 
all over the map.

The architecture that works best is encoding the actual picture height and 
width and frame rate, and making the decode/display rendering device adapt to 
its current display circumstances.  That means you might want to watch a 2.35AR 
movie on your iPod with a 1.5AR screen "center cut" because of the small 
screen, but when you plug it into a TV connection going to a 1.78AR display 
using 1.78AR signal format you might tell your pod to letter box it with common 
sides or a slight side crop.  If you had a built in display that was 2.35AR you 
could display full screen/wide screen, but most displays don't support wire 
formats that will take a 2.35AR signal, so you have to pad to a 1.33 or 1.78 
frame.

The basic architecture that works is to encode the content with its original 
source characteristics ... don't hide 24p content in 60i encoding (e.g. Blu-ray 
vs. DVD), and don't hide 1.33, 1.85 - 2.35AR movies in 1.78AR encoded frames.  
Then the device doing the decoding has all the information it needs to frame 
the content for a directly connected display, or a wire format that restricts 
the output options allowed for an external display.  In my world, we have to 
assume the same content file will be viewed on lots of different devices and 
displays, so there's no option to encode it as though every display is a 16:9 
TV and let the others suck (the Blu-ray AR problem:  Blu-ray is locked to 16:9. 
DVD was smarter because it was designed to handle a mixed 4:3 and 16:9 TV world 
with adaptive framing in the device).

We are going through a painful transition where there are conflicting 
distribution architectures resulting in both rending devices and displays 
fighting to control picture framing and refresh, resulting in postage stamp 
pictures surrounded by letter boxes and pillar boxes and other nonsense.  
Happily, the frame rate part of the problem is underway with most modern 
displays supporting 24P wire formats and many even have a "leave it alone" 
setting to avoid scaling up the image and cropping the edges off to simulate a 
cathode ray tube with a bad power supply.  Interlace encoding is fading into 
the sunset very slowly along with the dinosaurs.  Now we need to make progress 
on picture framing in a way that works in a world with an increasing variety of 
video devices, where the display framing is done by the decoding device with 
accurate information about the encoded picture and whatever wire format it 
might be currently connected to (or not, with direct display control such as 
internal or VGA multisync).

Kilroy 

-----Original Message-----
From: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] On 
Behalf Of Stessen, Jeroen
Sent: Wednesday, October 07, 2009 4:20 AM
To: opendtv@xxxxxxxxxxxxx
Subject: [opendtv] Re: 70th Anniversary Blu-ray and standard DVDs of the Wizard 
of Oz

Hello,

Bert Manfredi wrote:
> This is disturbing, Jeroen. I would rather crop the 4:3 frame some,
> to make it look wider, than be forced to watch all 4:3 content
> distorted! 4:3 is still quite common in non-prime-time.

Don't worry, we have many such modes. For 4:3 content on a 16:9 display:
- true 4:3 with wide side pillars (12.5% on each side, ignoring overscan)
- 14:9 movie expand = 16.7% enlarge + 2x  7.1% vertical cropping
- 16:9 movie expand = 33.3% enlarge + 2x 12.5% vertical cropping
- 16:9 movie expand with subtitles = same as previous, but more of the
  vertical cropping happening at the top, to protect the *sub*titles
- superwide / panorama mode = 33.3% non-linear enlarge (more expansion
  at the sides than in the middle) + 2x "some" vertical cropping
- auto-format, where the choice between 16:9 movie expand and panorama
  mode is made intelligently based on a measurement of the letterbox
  bars, and of course for true 16:9 content nothing needs to be done.
Whenever there is vertical cropping, the viewer can shift the picture
up or down with the cursor keys on the remote control.

The out-of-the-box setting is auto-format, and with a combination of
reliable widescreen signalling information and black bar detection this
means that the viewer normally does not need to do anything anymore.
Plus, with more than half of the broadcast content already being 16:9,
it is quickly becoming a non-issue. (Until the 21:9 display, that is.)


Cliff Benham wrote:
> The second chart lists all the aspect ratios of films available on DVD.
> Note that the number of 4:3 films on DVD is greater than the number of
> ALL those in *other aspect ratios*.

For movies ?! I understand that DVDs of (older) TV series are all 4:3,
and these are sold in very large quantities. But of the movie DVDs that
are sold in the shops here, I bet that over 90% are "anamorphic" 16:9.
And a fair percentage of those are letterboxed within the 16:9 frame
for an even higher aspect ratio, typically 2.35:1.
I don't think that we ever see movies anymore that are letterboxed
within a 4:3 frame, and very few movies that are original 4:3 or cropped
to 4:3. In Europe, the 4:3 format is really dead for any new products.

I have never seen a 16:9 DVD (or a D2MAC or DVB broadcast) that
implemented dynamic pan-and-scan for cropping to 4:3. I am not against
pan-scan, witness my patent US20040130664. It just never happens ?

Groeten,
-- Jeroen

  Jeroen H. Stessen
  Specialist Picture Quality

  Philips Consumer Lifestyle
  Advanced Technology  (Eindhoven)
  High Tech Campus 37 - room 8.042
  5656 AE Eindhoven - Nederland




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