[linux-audio-dev] Re: chebychev

[Steve Harris]

On Fri, Nov 01, 2002 at 05:47:04 +0100, Tim Goetze wrote:
> the difference between the two is next to nothing, mostly a DC
> offset. i'll use yours for the next FTs. is that 'Harris' as in
> 'S.W.Harris'? ;)

Er, no ;) Harris is a very common surname.
 
> after some NR 5-10 reading, it looks to me like harmonic_gen is 
> missing the work pcshft() from the book text is performing, yet
> its output seems well-scaled.

I think thats for rescaling the domain from [-1,1] to [a,b], but our
domain is [-1,1], more-or-less, so we are OK. To make sure we should
probably clamp the input to [-1,1]. I could also have remembered it wrong
though.

> it just occurred to me that it may be feasible to skip the
> coefficient calculation in realtime by simply storing these
> instead of harmonic amplitude tables. makes lerping difficult
> though.

IIRC that is what we discussed before. It might well work, but its just an
optimisation, so best leave it out for now.

- Steve