[FFmpeg-devel] [RFC] support encrypted asf

[Uoti Urpala]

On Tue, 2007-10-09 at 10:01 +0200, Reimar D?ffinger wrote:
> > static uint32_t inverse3(uint32_t v) {
> >     uint32_t i;
> >     i =  2 - v;
> >     i *= 2 - v * i;
> >     i *= 2 - v * i;
> >     i *= 2 - v * i;
> >     i *= 2 - v * i;
> >     return i;
> > }
> 
> Interesting, in case you didn't notice this ended up being a
> fixpoint-iteration. I wonder if there is an easy way to prove
> convergence in 5 steps in that mindset...

The number of correct low bits doubles at every iteration, so starting
from any number with lowest bit 1 will give 32 correct bits in 5
iterations.