[chuck-users] 8-bit?

Kassen signal.automatique at gmail.com
Sat Nov 27 23:14:38 EST 2010


I'm grateful that Kassen dropped some code for LiSa, because I didn't

> understand his description until I was knee deep in CurveTables and
> had finally worked through all the problems Kassen's succinct proposal
> addresses.

You're welcome, as always. It's also nice to see how a formal language can
sometimes be *easier* to understand than a natural one. I think that's a
non-trivial point if we want to consider the relative importance of
livecoding. :¬)

> While I got the CurveTable working, I can't get real sharp
> transitions between the quantization levels because CurveTable crashes
> if I give it a coefs array with more than 35 points.
Weird, and what a odd number for it to crash at; I'd expect a power of 2.
Just increasing the resolution should help but as you note; LiSa is happy to
deal with hundreds of thousands of points. Interestingly, for this
niche-application; LiSa, unlike SndBuf, has no option to turn off
interpolation. If she did we could stick to far smaller tables and a lower
overhead setting them. Not sure that's worth "fix" because this is a bit of
a niche application and a "proper" crusher might be a much nicer investment
of dev-time.

As a side-note; a big part of the sound of older d-a converters came from
deviations in the actual value of the resistors in them compared to their
nominal value (to put it bluntly; cheap crap was used). Basically that means
the "steps" aren't all the same height. If you really want to emulate that
things will get a bit more tricky. It's interesting though, because if we
discard quantisation in the time domain the errors of bit-depth crushing
should all be harmonic so such errors should give slightly different
spectra. I don't think many implementations do this.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.cs.princeton.edu/pipermail/chuck-users/attachments/20101128/88e58a9b/attachment.htm>

More information about the chuck-users mailing list