[MPlayer-dev-eng] [PATCH] Make vo_gl / fragment programs work with Mesa

[Reimar Döffinger]

Hello,
On Thu, Mar 01, 2007 at 11:26:45AM +0100, Matthias Hopf wrote:
> On Feb 28, 07 21:27:24 +0100, Reimar Döffinger wrote:
> > I think that any such solution will mean much more instructions and
> > probably give speed problems for fullscreen videos.
> > How about attached patch instead? It adds an interpolator that is
> > cubic only in X-direction. Doesn't look too bad IMO.
> > It could be further simplified if texture swizzles were supported *g*
> 
> I don't think having X only cubic interpolation will help much -
> artifacts seen in bilinear interpolation are typically seen, because
> horizontal/vertical interpolation is linear, while diagonal
> interpolation is quadratic. If you interpolate cubic in X, this will not
> change this basic property here. So I don't think it is worth the
> hazzle.

Well, in theory yes. But in practice what is most annoying to me with
linear scaling is the "wandering staircase" (aliasing?) effect on moving
diagonal lines, and interestingly that is almost gone with this mode, at
least for horizontal pans.
So for me, this mode is more useful than expected. It might also be
useful for interlaced content, since without scaling the linear
interpolation should not smear out the interlacing, which cubic scaling
would always do.

Greetings,
Reimar Döffinger