[MPlayer-dev-eng] [PATCH] A new ASS renderer

[wm4]

On Sun, 23 Sep 2012 16:10:28 +0200
Reimar Döffinger <Reimar.Doeffinger at gmx.de> wrote:

> The when running on the GPU, the alpha blending does not take any
> relevant amount of time, what breaks the GPU render's neck is when
> it has to upload 10000 2x2 images that are then stored in 10000
> different textures.

In my hacks to vo_gl, I reduced the number of textures needed for EOSD
to 1, with 1 upload per frame. The CPU still needs to memcpy the images
to pack them, though. This was a performance win, especially on OSX for
some reason.

> > > Only libass can e.g. look ahead
> > 
> > You could easily request a frame from the future from libass,
> > provided libass has received all necessary subtitle packets. The
> > rendering interface takes a time value.
> 
> That is useless, since what you need is to have all glyphs that are
> used repeatedly in future frames are stored together in a shared
> memory area (and preferably without introducing yet another memcpy),
> whereas all that are used only a few times are not there but still
> grouped together so they can be processed in one go.

What do you mean by grouped together? Packed into a rectangular
bitmap?