Re: [VCDImager] Newbie svcd quiestion

[Roman Hochleitner]

On Thu, 13 Dec 2001, Matto Marjanovic wrote:

> 
>  >The SVCD spec requires that the mpeg video be exactly 480x480 
>  >resolution. No more, no less. Don't worry about the aspect ratio 
>  >though--all pixels are not square and it will look just as it should. 
>  >So, just scale in the width to 480 and you're good to go.
> 
> I was under the impression that it was "2/3 D1" --- i.e. scaled from 720
>  to 480 in width (and height stays 480/576 as appropriate for NTSC/PAL).
> 
> For NTSC:
>   This would mean a pixel aspect ratio of 11:15 (as opposed to 11:10 for
>   the original 720x480 frame).  A 640 wide source would need to be padded
>   to ~654 wide before being scaled to 480.
> 
> True?

pixel aspect ratios are only relevant to MPEG 1
MPEG 2 uses display aspect ratios except the square pixel (==VGA) mode

 4:3 display
 16:9 display
 2.21:1 display

so in theory you could make a 120x800 movie with an display aspect ratio
of 4:3 and you'll get 4x3 as expected ;)

usually the DVD's are 4:3 with black borders, instead of 2.21:1 without
black borders, which would be much more decent on a 16:9 tv.

-- 
mfg Roman
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Roman HOCHLEITNER              address@hidden
student at the Vienna University of Technology AUSTRIA
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