From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263664AbUH1DgA (ORCPT ); Fri, 27 Aug 2004 23:36:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264386AbUH1DgA (ORCPT ); Fri, 27 Aug 2004 23:36:00 -0400 Received: from jib.isi.edu ([128.9.128.193]:55688 "EHLO jib.isi.edu") by vger.kernel.org with ESMTP id S263664AbUH1Df6 (ORCPT ); Fri, 27 Aug 2004 23:35:58 -0400 Date: Fri, 27 Aug 2004 20:35:52 -0700 From: Craig Milo Rogers To: QuantumG Cc: linux-kernel@vger.kernel.org Subject: Re: reverse engineering pwcx Message-ID: <20040828033552.GN24018@isi.edu> References: <412FD751.9070604@biodome.org> <20040828012055.GL24018@isi.edu> <20040828014931.GM24018@isi.edu> <412FF888.8090307@biodome.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <412FF888.8090307@biodome.org> User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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