[XviD-devel] GMC update

Marco Al xvid-devel@xvid.org
Thu, 2 Jan 2003 10:07:26 +0100


Christoph Lampert wrote:

> Btw. creating the transformed image is integer-only again, but it's really
> ugly "ISO standard"ish code:


Why not jack FFMPEG's code? It seems to come from one of the reference
implementations rather than the standard, it has a more sane incremental
implementation. It is LGPL so you can relicense it to GPL.

> (so global motion is 16th-pel resolution and is bilinearily interpolated)

Isnt the resolution variable?

> Any ideas how to speed this stuff up, maybe even MMX?

If anyone wants to do it they might want to consider asking Andreas Dehnhardt
for his thesis, he implemented on a 64 bit SIMD processor (which is bound to be
pretty close to MMX). There is an old version on his website which only explains
the process of GMC and analyzes the incremental version of GMC from the
reference code, but it lacks any of the conversion to SIMD :

http://www.stud.uni-hannover.de/user/73346/StA-Dehnhardt.pdf

Marco