Re: [linux-audio-dev] ANN: libgdither 0.6

On Tue, Jul 26, 2005 at 05:51:09 +0200, Alfons Adriaensen wrote:
> On Tue, Jul 26, 2005 at 09:45:45AM +0100, Steve Harris wrote:
>
> > Yes, note that its not much good as a random number generator as
> > its easily predictable,
>
> All 'psuedoramdom' generators are predictable, that doesn't make
> them less 'good', except for cryptographic applications.
>
> > but in this case all thats required is that it
> > produces noise that is approximatly white (ie. equal energy in each
> > frequency band), and its efficient.
>
> It's a perfectly good choice for this application. Its only problem
> is when you use it to generate random *bits*. Witm m = 2^N, the
> lower n bits will form of cycle of lenght 2^n, so e.g. the LS bit is
> just altermating 0,1,0,1,0,1 -- not very random.

True, but I'm casting it to a float, so the LS 7-ish bits will be lost
anyway, and the ones above should have sufficiently long period that they
won't be noticable, even if it weren't used for dithering :)

- Steve
Received on Tue Jul 26 20:15:27 2005