[MPlayer-users] Question about dvd resolution

[Stephen Mollett]

On Monday 10 Mar 2003 18:38, Shane Wegner wrote:
> In encoding a 16:9 DVD movie, I get the following from
> mplayer when playing the actual dvd.
> VIDEO:  MPEG2  720x480  (aspect 3)  29.97 fps  12250.0 kbps
> ...
> VO: [null] 720x480 => 854x480 Mpeg PES
> Why the two resolutions?

The file is actually 720x480, but because it's 16:9, if you displayed it at 
720x480, it would come out 'squashed' horizontally on a 4:3-aspect monitor. 
So it's scaled up to 854x480 to compensate.

> Now when I play the encoded avi with
> lavc, the aspect ratio changes.
> Movie-Aspect is 1.97:1 - prescaling to correct movie
> aspect.
> VO: [null] 720x366 => 720x366 Planar YV12
> why has the aspect ratio changed?

The aspect ratio has changed because you've cropped the black bands and thus 
changed the height. Aspect ratio for square pixels = (width/height):1

Stephen