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This topic is a branch from that started here: http://www.avsforum.com/ubb/Forum10/HTML/006503.html#29


The more I think of it, the less I want a Pan & Scan created on the fly from vector data and a single 2.35 or 1.85 source on a DVD.


Why?


Because the way 2.35 and 1.85 DVD's are mastered, you lose a significant amount of vertical resolution due to letterboxing of the 2.35/1.85 image in a 1.78 frame.


If you have both OAR and 4:3 P&S versions complete on the disc, the P&S will then have 480 vertical pixels of resolution, rather than almost half that for 2.35 movies. If vector data were applied to create a P&S 4:3 from an anamorphic 2.35 image, the scaled up 270 or so vertical pixels would look much poorer than a native 480 pixel high 4:3 DVD image.




[This message has been edited by Rgb (edited 06-06-2001).]
 

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Good idea to branch. We were off topic.


To summarize for others, we were musing as to why digital presentations are not accompanied with information that indicates where a Pan & Scan (P&S) focus should be at any given point in a movie. These vectors/coordinates would allow either of the Original Aspect Ratio (OAR) or P&S editions of a presentation to be viewed at the option of the user.


This seems an obvious solution to many and was originally discussed in the context of HD presentations. However, it could also be applied to DVD presentations and RGB has indicated that this is apparently part of the DVD specification.


Meanwhile, back at the ranch, RGB makes a good point. The good news (for OAR fans) is that most DVDs have been released with the OAR edition, some with the P&S edition on the other side. The application of vectors to NTSC presentations is more difficult for the reasons RGB provided. The good news for NTSC DVDs is that there is room on the existing generation of media for both editions to cohabitate.


HD presentations have the same issue, except that the resolution is significantly higher. A 16:9 vectored presentation of a 2.35:1 encoded presentation would result in a 33% loss in vertical resolution. Assuming 1080i, that would leave "only" 720 vertical lines. Anamorphically encoded presentations do not help in this situation. In fact, assuming a display capable of squeezing anamorphic presentations, it is ironically an "upside down" situation where the 2.35:1 edition would have a higher vertical resolution than would the 16:9 vectored presentation! The difference is that movie buffs and anti-blackbarers are both well served.



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Oops. Didn't pick up the branch. I'll repost here, even though some of the issues have already been brought up...


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RGB: actually, the idea is to have two or three panning and scanning vector options for all viewings, including those at the digital theaters. As has been stated above, a whole lot of cropping is going on currently. Having pan-and-scan vector options would give directors control over how it is viewed in many fixed-width environments. It would work best on HD materials, since we have resolution to spare.


Of course, in film-based theaters, this would be more difficult and would necessitate a separate mechanical part.


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Dan


[This message has been edited by dschmelzer (edited 06-06-2001).]
 

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I do not believe that the Mona Lisa would be as effective in landscape mode. Nor would Sunday Afternoon in the Park benefit from portrait mode. An artist must be left to choose their pallet. I don't have a problem with 4:3 if that is the way it was intended by the artist. Though I am left wishing it were wider.




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As far as I know, the DVD spec. for pan and scan on the fly always takes a 480 high by 540 wide portion of the DVD video frame, in other words provides only horizontal panning. It only works with 16:9 enhanced programs where 540 pixels across corresponds to a 4:3 portion of screen area. Only the 1.78:1 aspect ratio movies would have picture material on all 480 active scan lines. If the movie was 2.35:1, with the pan and scan on the fly it would still be letterboxed (1.75:1 aspect ratio worth of material remaining) on the 4:3 screen because it does not do any vertical zooming.


Other video hints: http://members.aol.com/ajaynejr/video.htm



[This message has been edited by Allan Jayne (edited 06-06-2001).]
 
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