[Mplayer-advusers] trouble with the -vm option

[Christian Ohm]

On Tuesday,  2 July 2002 at  0:25, Arpi wrote:
> > well, it would be nice if monitoraspect would be used in the scale plugin
> > when zoom isn't selected. right now i have a fixed aspect in my config and
> > have to play when a movie isn't 4:3.
> 
> imho it's bad, very bad idea:
> - it's on -vo drivers how to handle monitoraspect, more over, coming from
> current mplayer architecture, teh video filter layer cannot even access this
> info

yeah, i thought so.

> - encoding files to the aspect ratio for _your_ monitor is a bad idea, think
> if someone with different monitor wants to playback it... also think if
> _you_ want to playback it, then the monitoraspect value will be applied
> _twice_

haven't thought about that, since i have used mencoder only to repair some
screwed files.

> > btw, the manpage mentions -1 for scale to use the aspect ratio of the movie,
> > but actually it is -3 for movie aspect, -2 for monitor resolution aspect
> > (without using -monitoraspect).
> 
> huh?
> 
>     if(vf->priv->w==-3) vf->priv->w=vf->priv->h*width/height; else
>     if(vf->priv->w==-2) vf->priv->w=vf->priv->h*d_width/d_height;
>     if(vf->priv->w<0) vf->priv->w=width; else
>     if(vf->priv->w==0) vf->priv->w=d_width;
> 
> so:
> -1 -> use original (without prescaling ie without -aspect) w/h
>  0 -> use prescaled (-aspect value applied) w/h
> -2 -> calculate w from h using prescaled aspect (-aspect applied)
> -3 -> calculate w from h using original aspect (-aspect ignored)

ah, so i got -2 wrong... well, imho -2 and -3 are the most useful, and those
aren't mentioned on the manpage.

> note that -monitoraspect is always ignored at vidoe codec/filter layer.
> it's, as its name says, is for video out to correct square pixels to
> monitor's pixel aspect. no sense and no way of calculating -monitoraspect
> into -vop scale.

what about another parameter to scale, that gives a custom aspect ratio by
which to scale the output?

bye
christian ohm

-- 
When I'm good, I'm great; but when I'm bad, I'm better.
		-- Mae West