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Discussion Starter · #1 ·
Something has been puzzling me for sometime. Perhaps someone clever can enlighten me?


Do anamorphic DVDs carry the picture on the full 480 lines, *irrespective of the aspect ratio*? i.e. 4:3, 16:9, 22:9 etc. I assume they just carry the picture in a more or less "squished" format and that all 480 lines are used for the picture?


The reason I ask is this: It occurred to me some while ago that since plasmas are digital devices inasmuch as they have a fixed 16 x 9 array of pixels, then how would they cope with 22:9 pictures? The only way they can do this is to do it in "non-anamorphic" mode - i.e. to display the top and bottom lines black, and to use the remain pixels in the middle to display the image. Clearly lots of detail is lost, if (say) only 300 lines are available for the picture.


Its not the same on a good old 4:3 analogue CRT. These often have an "anamorphic" mode, where the TV's electronics simply adjust the V-gain to give the correct aspect ratio for the disk in question. Whatever the picture shape - 16:9, 22:9 etc. all of the detail is still displayed and nothing is lost. Effectively, the "pixels" (not that there are any on a CRT) are squished vertically to make sure that the image looks right on the 4:3 screen. This is obviously something that digital devices like plasmas just can't do.


So this might be a good argument for having more than 848x480 pixels on a plasma, even though DVD resolution is only 848x480. On the other hand, if anamorphic 22:9 DVD's aren't *completely* anamorphic (i.e. they too only use some of the available lines), then there's no point.


Am I explaining my question clearly, and can anyone clarify?


Thanks


Chip.
 

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I'm not sure about pixel counts and such. This is how it works from the user perspective: I have the Panny 42" (852x480) If you set your DVD player to a 16:9 display and then view an anamorphic DVD in the plasma's "normal" mode, a 16:9 DVD frame fills the screen vertically and is squished laterally into a 4:3 frame. (This mode is the one that displays a 4:3 OTA picture in proper proportions with gray bars on the sides.) A more extreme widescreen OAR picture has the same width with black bars top & bottom.


If you then watch this DVD in "full" mode, you get a properly-proportioned 16:9 picture that fills the screen. Again, if the widescreen aspect ratio is more than 16:9, you get a properly proportioned full-width picture with letterbox bars top and bottom. This says to me that the DVD with a very widescreen picture is only carrying, say, the 300 lines in the middle. The remianing lines in the anamorphic data are just black. So, if you have a CRT display that fills the screen vertically by increasing V-gain, you aren't seeing more information than with the plasma, you're just spreading those 300 lines of info over a wider space. You can do the same thing with the plasma's "zoom" mode, but you lose some picture at the sides and PQ goes down.


Remember, an anamorphic frame is only compressed in one dimension, so it can only be un-squished in one.
 

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Currently DVD's support ONLY 4:3 or 16:9 format. Movies at higher 2.35:1 are converted to 16:9 ( black bars ) for DVD.


So no there is no need for additional resolution. Plasmas as 848x480 are perfectly suited to progressive playback of 16:9 480p content.


Hope that answers your question
 

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Discussion Starter · #4 ·
Thanks guys.


Spoffo and yourself are basically saying the same thing - i.e. that 22:9 films are not *fully* anamorphic. They are only anamorphic up to 16:9 ratio, and after that its black lines top and bottom as well.


But how can you be sure that's true? Where did you get this info from? What you are saying is very plausible, but equally, so is that idea that 22:9 DVD's are fully anamorphic (i.e. carrying detail on all 480 lines).


Do you have any URL's or anything?


Thanks,


Chip.
 
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