[MPlayer-users] DVD aspect ratios

[Ville Saari]

On Mon, Mar 07, 2005 at 07:33:07AM +0100, Dominik 'Rathann' Mierzejewski wrote:

> > This of course applies to 4:3 image too. The numbers are 108/79 for
> > NTSC and 160/117 for PAL.
> 
> Are there any official docs supporting your claim available on-line?

I'm not aware of any official docs online, but anyone interested in
digital video aspect ratios should read this:

   http://www.uwasa.fi/~f76998/video/conversion/

Long time before I knew anything about this, I measured the the projection
properties of the optics of my PAL DV camcorder as accurately as I could so
that I could reproject the images on spherical surface for accurate stitching.
The aspect ratio I got from those measurements was 1.366848. Considerably
wider than 4/3, which puzzled me a lot.

The paradox disappeared when I learnt how the video aspect ratios really
should be calculated: 1.36685 matches 160/117 very nicely. The error
is approximately one third of a pixel, which is well within the inaccuracy
of my measurements.

-- 
 Ville