[sdiy] wavetable lookup waves

[John L Marshall]

I want to scare you some more. Far fewer non-redundant combinations than 3.2
x 10^616

If the wavetable is used alone and for audio only, then we can delete phase
and symmetries:
* The bit pattern shifted by one or more bits (phase) will sound the same.
* Vertical mirrors (amplitude) will sound the same.
* Horizontal mirrors (time) will sound the same.

* Any combination that yields fo in less than 256 Bytes isn't making best
use of the wavetable. If the pattern is complete in 128 Bytes and then
repeated in another 128 Bytes it will sound an octave higher but not the
most efficient use of the wavetable.

*Any combination that does not include maximum and minimum amplitude in the
sample. It will sound the same, just noisier.

Blue sky.

Now, since all of these bits are available, but there is significant
redundancy is there some clever method of building wavetables of greater
resolution in the same size ROM?

Could waves be mirrored; count up then down?

Could waves be mirrored; count, change sign then count again?

Could waves be segmented into parts A, B, C, and D?

Could wave segments be stored on ROM B and then be pointed at by ROM A?
(Sorta, kinda like a state machine.) (Granular sound?)

----- Original Message -----
From: matti <matti at devo.com>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Friday, December 28, 2001 3:40 AM
Subject: RE: [sdiy] wavetable lookup waves


> On Fri, 28 Dec 2001, Colin Fraser wrote:
>
> >
> > Eh ?
> >
> > 8 bits * 256 bytes = 2048 bits.
> > Possible combinations = 2 ^ 2048 = 3.2 x 10 ^ 616
> >
> > Colin f
>
> oh. less scary. thanks.
>
>
> -
> the chatter has stopped. oh joy. achmed, yon achmed, make my felt.
>
>