[opendtv] Re: Learning From the Veterans - local news in HD

  • From: Craig Birkmaier <craig@xxxxxxxxx>
  • To: opendtv@xxxxxxxxxxxxx
  • Date: Thu, 29 Apr 2010 13:42:17 -0400

At 9:55 AM -0500 4/29/10, Manfredi, Albert E wrote:
I chose my words carefully each time, Craig. I said that you can't take advantage of the HD resolution, and I believe I also said that the effect is more like looking at the image through a microscope. Or if I didn't say it, I thought it.
Your choice of words is not in question here. Your lack of understanding of the concepts we are discussing is the problem.
When the 4:3 HD source is resampled to 704 x 480 the analog screen will be filled; The level of detail may be lacking on the analog display, but that is the price one pays for continuing to use legacy TVs. And for most shots the level of detail will be adequate - the wide shots will have important detail that may not be resolved on an analog display.
Of course you see more detail. And that's actually a benefit in its own right, but it's not all that you can do with HD. For example, when watching football, you will not see more of the playing field than the guy watching on the old analog set, *if* you stick with the common sides rule. So you will not be able to take full advantage of what HD has to offer. 

HUH?
IF we shot sports with 4:3 HD cameras with SAFE IMAGE protection for the 16:9 extraction, the throw away areas would be at the top and bottom of the 4:3 NTSC/ATSC SD extraction. As was noted, I think by Mark Schubin, the full 4:3 image would have more of the bodies of the players in close-ups. The only compromise for live sports is that the 16:9 extraction from the HIGHER RESOLUTION 4:3 frame would need to be fixed - it would be very difficult to do real time Tilt and Scan for live sports. If the full 4:3 frame is recorded, however, edited highlights could use Tilt and Scan.
The 16:9 extraction would take FULL ADVANTAGE of what HD has to offer. It would be full HD resolution. 

Do you need a tutorial on Tilt and Scan? Here it is in one sentence.
With Pan and Scan, the 4:3 image is extracted from the 16:9 frame by smoothly moving the extraction window right or left; with Tilt and Scan the 16:9 extraction window is moved up or down within the large 4:3 frame. 






 Sorry, but you are incorrect. Common sides allows the PROPER
 creation of both HD and SD versions with new information entering
 both frames at the same time from the sides.
Which is exactly why you can't full advantage of the HD. It's not so hard to grasp, is it? 


Apparently it is for you.
It works exactly the same way on your computer. Change the resolution setting in the video card. What is the effect you see? The higher the resolution setting, the more text or graphics you can fit in the monitor. By sticking religiously to the common sides approach, you are in effect always setting your HD monitor to sub-VGA modes. Plenty of detail, but no more text than that old NTSC TV monitor could handle. I know we all agree on this, and yet you and Mark keep telling me I'm wrong. Nonsense. 

You summed it up nicely in one word. NONSENSE.
This has NOTHING to do with changing the resolution on the HD display. It DOES mean you need a 4:3 camera with 25% more vertical lines than today's HD cameras. Instead of 1920 x 1080 it becomes 1920 x 1440. The 16:9 extraction is still 1920 x 1080. 

NO COMPROMISE HERE!
The compromise is with the old NTSC display. Yo are now trying to view an HD image on an SD display; an image that has 25% more information (additional picture area) than the 16:9 HD display. For virtually everything Hollywood does, this is not a big deal, as good cinematography has never had much to do with resolution. E.g. in NTSC you see flat skin tones, in HD you see skin pores. For live sports the common sides approach would make everything in wide shots appear smaller.
Rather than thinking about how this would look on an NTSC display, think about what HD football looks like on an LCD panel with a 20 inch diagonal viewed from seven picture heights. 

Like ants marching...
Your explanation above seems to describe what happens when you display NTSC on a high resolution computer display. If you fill one (or both) axis of the screen the NTSC image will look soft and the text will typically be large and fuzzy. If you tried to display an Internet web page that is composed for a 1024 x 768 computer display on an NTSC monitor it would be unreadable after proper filtering to eliminate interlace flicker.
As has already been noted in this thread, HD is currently compromised by the need to extract a 4:3 version. Thus we have wasted throw away areas on the sides of most current HD content. That is, the safe image area of the content is withing the 4:3 extraction. This is especialy noticeable with the graphics in HD porting events - all graphics appear within the 4:3 extraction frame.
But it gets worse. All of the graphics must be sized so they can be read on an NTSC display. There is no way to take full advantage of the resolution of the HD display.
But wait, that's not the only problem. The graphics must also be sized so they can be read on small flat panel "so called" HD displays.
This is the real difference between TV and computer displays. With TV the lowest common denominator display dictates what can be shown to the masses. With computers the canvas always has consistent resolution - typically around 100 dpi (I know this is variable on most machines, but as a content creator, you must assume the nominal average for all machines. With computers, as the display area gets larger the canvas gets larger; typically you display more content rather than magnifying the image relative to the common 15-30 inch viewing distance.
The good news is that the large screen TV display in the family room may be constrained by a broadcast system optimized for the lowest common denominator, you still display much higher levels of detail from other sources, like the Internet. 


 > You need to think like a cinematographer or videographer. When

 working with multiple aspect ratios you need a common safe area
 which needs to include the information that everyone must see.


Of course. Now ask yourself this:
If you are a videographer and you're shooting a football game, or a documentary that shows landscapes, for HD and SD consumption, why would you religiously stick to the common sides rule? Why not instead allow wide screen sets, which are by the very VAST majority HD sets in the US of A, to gather more horizontal content than the 4:3 (aka analog) sets? Do you really need to show players entering and exiting the sides of the the screen at the same time, in 4:3 and 16:9? No.
Obviously there are many approaches. As we have discussed here, ad nauseam, even the "inventor" of 16:9 acknowledges that we looked at this problem the wrong way.
The result is that HD IS COMPROMISED today because we extract the 4:3 safe action area for lower resolution displays (please re-read the discussion above if you doubt this).
The common sides approach using a HIGHER RESOLUTION 4:3 HD frame moves the compromises from the HD version to the legacy HD version as it should have been. 




 Fox is a broadcaster.
Sorry, you are incorrect. Fox is the network, and may or may not be the broadcaster in your market. When this business about letterboxed Fox prime time came about, I was informed that the NETWORK policy for Fox was to not use letterboxing. 

I choose my words carefully Bert.

Fox IS a broadcaster.

They own broadcast stations.
They operate a network that is distributed exclusively by broadcasters and dictate how that content is to be presented.
So the Fox BROADCAST Network made the decision NOT to offer the networks content in letterbox.
You are playing semantic games here Bert. The vast majority of broadcasters and their networks chose not to compromise NTSC and take "full advantage of HD." They chose to compromise HD.
I have now reached the point Mark reached several days ago. I no longer have the time to waste trying to educate you. 

Regards
Craig



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