[MPlayer-cvslog] r20272 - in trunk/libmpcodecs: Makefile vf.c vf_geq.c

[Diego Biurrun]

On Sun, Nov 05, 2006 at 06:48:19PM +0200, Oded Shimon wrote:
> On Sun, Nov 05, 2006 at 02:13:14PM +0100, Diego Biurrun wrote:
> > On Thu, Oct 26, 2006 at 01:59:29PM +0200, Michael Niedermayer wrote:
> > > 
> > > On Tue, Oct 24, 2006 at 08:52:16PM +0200, Diego Biurrun wrote:
> > > > 
> > > > Plus, this is still lacking a description of the constants
> > > > ("PI", "E", "X", "Y", "W", "H", "N", "SW", "SH").
> > > 
> > > PI, E see wikipedia
> > > X and Y are the coordnates of the current sample
> > > W and H are width and height of the image
> > > SW and SH are width/height scale (for YUV 4:2:0 they are 1,1 and 0.5,0.5)
> > > depending on the currently filtered plane
> > 
> > OK, how about
> > 
> > geq=equation
> >   generic equation change filter
> >  
> >   <equation>
> >   Some equation, e.g.\&  'p(W-X\,Y)' to flip the image horizontally.
> >   Note that this filter does not yet understand whitespace used to
> >   make the equation more readable.
> >   There are a couple of constants that can be used in the equation:
> >     PI: the number pi
> >     E: the number e
> >     X / Y: the coordinates of the current sample
> >     W / H: width and height of the image
> >     SW / SH: width/height scale depending on the currently filtered plane,
> >       e.g. 1,1 and 0.5,0.5 for YUV 4:2:0.
> most importantly:
>       function p(x,y): returns the value of the pixel at location x/y of 
>       the current plane.

 geq=equation
   generic equation change filter
  
   <equation>
   Some equation, e.g.\&  'p(W-X\,Y)' to flip the image horizontally.
   You can use whitespace to make the equation more readable.
   There are a couple of constants that can be used in the equation:
     PI: the number pi
     E: the number e
     X / Y: the coordinates of the current sample
     W / H: width and height of the image
     SW / SH: width/height scale depending on the currently filtered
       plane, e.g. 1,1 and 0.5,0.5 for YUV 4:2:0.
    p(x,y): Returns the value of the pixel at location x/y of the
       current plane.

Something like this?

Diego