[vdr] Re: divx with horizontal 768 pixels

[Mike Pieper <mptei@t-online.de>]

On Saturday 15 June 2002 14:17, Tobias Kerner wrote:
> Mike Pieper wrote:
> > Full PAL resolution is 720x576. But the TV-pixels are not square. If you
> > want to have square pixels to show it on a computer screen (which has
> > square pixels) you have to scale it to 768x576. Because AVI-files are
> > primary intended for use on computers they use this resolution. If they
> > would have a 720x576 resolution you wouldn't have a good picture on a
> > computer monitor.
> >
> > In the opposite direction (output on TV-out of a DVB-card) you have to
> > keep in mind that this card 'knows' about the non square TV-pixels.
> > Therefore the maximum resolution is 720x576. You have to scale your video
> > to 720 pixel (which would look slightly squeezed on computer screen) to
> > get a correct output on the TV (in fact your TV will stretch it).
> >
> > Mike
>
> now I understand. I always thought the TV pixels are stretched in the
> heighth. so when I have a 4:3 movie with a resolution 544x576 recorded
> with vdr and now I want to convert it to divx, should I scale it to
> 720x576 (no the correct aspect ratio) or 720x540 (aspect ration would be
> correct then)?

In my opinion, the best thing is to not scale it at all. When you scale it up, 
then you waste space. When you scale it down then you lose resolution.
Normally the viewer/player should scale it, while playing. The DVB card is 
able to support the resolutions which are typically used in TV transmission 
(sorry I don't know which exactly this are).

How do you play the avi-files? If you use mplayer, then mplayer should scale. 
The output module for DVB should know about the unsquare pixel.

Mike