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#125817 - 12/11/2002 17:38 Anamorphic DVD movie aspect ratios
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
Many DVD players have the capability of playing DVDs at a native 16:9 aspect ratio. I believe that the support for this lies in the DVD in addition to the DVD player. The benefit of this being that if you're watching a movie in widescreen, the anamorphic mode allows you to have more horizontal lines of resolution actually being used on the TV for the picture. If you were to view this anamorphic mode on a ``normal'' TV, it'd appear squished left-to-right, so that everyone would appear to be very tall and thin. I say that so that those of you that aren't able to view this mode won't get totally confused by the question I'm about to ask.

This is probably also specific to NTSC, but if anyone in PAL- or SECAM-land wants to add anything, I'd be happy to hear it.

So, for those of you that have 16:9-capable TVs:

Have you noticed that some DVDs are apparently not encoded correctly, so that, even though movies that should still be (slightly) letterboxed on the 16:9 TV aren't, so that you still get (slightly) tall-and-thin people? I've noticed this on a few DVDs I've rented recently, and, initially, I thought that my TV might need to be tweaked a little for size, but then I'll play other movies and they look fine. And it's all definitely in 16:9 mode, because I can tell both when the TV switches from 4:3 to 16:9 and I can tell the difference between the scanned vs. non-scanned black.

(It's interesting to note that most movies are still slightly letterboxed on 16:9 TVs, as, apparently, one of the deciding factors for choosing 16:9 (about 1.77:1) was that it was somewhere inbetween the NTSC aspect ratio (4:3, or about 1.33:1) and the narrowest commonest movie ratio (1.85:1), thus allowing current TV to not be ``too'' inverse-letterboxed, nor movies ``too'' letterboxed.)

Does anyone have any idea if this might be a problem with my DVDs, my DVD player, my TV, or any, or all, of the above?
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Bitt Faulk

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#125818 - 12/11/2002 18:11 Re: Anamorphic DVD movie aspect ratios [Re: wfaulk]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
The telecine transfer of a given movie can be a little off, yes. But I've only seen SLIGHT variations, nothing major.

My 16:9 TV is carefully tweaked for horizontal/vertical size and alignment using a DVD called "AVIA" which has test patterns for the exact anamorphic ratio and overscan marks.

Once I got those test patterns looking right, the subtle variations in ratio from movie to movie became not-noticeable.

However, I know that there are some TVs and some DVD players that try to auto-correct certain things. For instance, I think certain Panasonic players will auto-stretch a letterbox (non anamorphic widescreen) to properly fill a 16:9 screen set to anamorphic mode. Dunno if that's what's happening.
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Tony Fabris

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#125819 - 12/11/2002 19:06 Re: Anamorphic DVD movie aspect ratios [Re: tfabris]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
I purchased AVIA, and they claim that they were unable to force the 16:9 mode for the 16:9 test patterns, so they show it compressed and that I should force my TV into 16:9 mode. Unfortunately, I can't do that, so it's useless for me for 16:9. Wonderful otherwise, though. Too bad they couldn't figure out how to force 16:9 mode, since most DVDs I've seen have switched modes back and forth between the menu and the movie.
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Bitt Faulk

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#125820 - 12/11/2002 19:34 Re: Anamorphic DVD movie aspect ratios [Re: wfaulk]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
That's odd, I've never seen that problem. Your DVD player should just be in 16:9 mode all the time if you have a 16:9 television. That could be related to the problem with the other movies.

I recommend asking this question in the DVD hardware forums at www.hometheaterspot.com which is a BBS almost as useful as this one is. Make sure to give them your make and model of DVD player and TV, and tell them what input on the TV you are using to hook up the DVD player. Also make sure to mention the thing about AVIA since that's the first thing they'll ask.

They'll get you sorted out
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Tony Fabris

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