Re: reverse engineering pwcx

Craig Milo Rogers
2004-08-28T03:36:00Z

On 04.08.28, QuantumG wrote:
> Craig Milo Rogers wrote:
>
> > Hmmm... a poster on Slashdot claims that entropy measurements
> >imply that the pwcx code is interpolating rather that truly
> >decompressing. Again, that's integer math and table lookups.
> >
> >
>
> http://www.amazon.com/exec/obidos/tg/detail/-/B00005R098/102-7619892-0201738?v=glance
>
> claims that the Logitech Quickcam Pro 3000 is a "True 640 x 480
> resolution video capture" which is now clearly false.

If the "now clearly false" is meant to be a consequence of the
entropy measurements poster I referred to, I wouldn't jump the gun.
On reflection, it's entirely natural for a decompressed stream to
examine less entropy than the corresponding compressed stream!

Craig Milo Rogers