[MPlayer-DOCS] scale video filter

[D Richard Felker III]

On Sat, Sep 11, 2004 at 09:33:22PM +0200, Diego Biurrun wrote:
> Hi!
> 
> In the description of the scale filter d_width and d_height is
> mentioned:
> 
> scale[=w:h[:interlaced[:chr_drop[:param[:presize]]]]]
>   Scales the image with the software scaler (slow) and performs  a
>   YUV<->RGB colorspace conversion (also see -sws).
> 
>   w,h
>     scaled width/height (default: original width/height)
>     NOTE:  If -zoom is used, and underlying filters (includ-
>     ing libvo) are incapable  of  scaling,  it  defaults  to
>     d_width/d_height!
>       0:   scaled d_width/d_height
>      -1:   original width/height
>      -2:   Calculate w/h using the other dimension and the
>            prescaled aspect ratio.
>      -3:   Calculate w/h using the other dimension and the
>            original aspect ratio.
> 
> What the heck is d_[height|width]?  Attila said it was an internal
> libvo variable.  He did not know whether this was before or after
> aspect correction, though.  Can somebody shed some light on this?
> 
> Diego

d_width/d_height is the final "intended display size" passed out from
all previous filters. naturally this incorporates aspect.

rich