[MPlayer-dev-eng] Re: [PATCH] New video filter: deblendlogo

[Trent Piepho]

On Thu, 24 Feb 2005, Oded Shimon wrote:
> Done.
> 
> Adds YV12 support to this deblendlogo filter.
> Almost a complete re-write of the original filter.
> Unlike original filter, it accepts only a filename, no offset, and the png 
> image has to be the same res as the video frame.

You could try premultiplied alpha to make it faster.  You inner look looks like
this:

  pic_plane[x] = CLIP((pic_plane[x] - tmpl_plane[x] * alpha) / (1.0 - alpha));

You can calculate tmpl_plane[x] * alpha once after the image is converted to
YV12 and just store it instead of the original image.  The same with 1-alpha,
just store it instead of alpha.