High Quality mode for all effects!!!!

Angstrom · Post by **Angstrom** » Sat Mar 22, 2008 5:15 pm

well, interpolation is different from oversampling.
"high quality mode" is the upsampling, calculation and then downsampling
interpolation is the process of calculating the unknown value between two known values.
Interpolation is normally described by the method used, which in this case I am guessing is 'linear'.

IE, I have two known amplitude values 0.8 and 0.1 and I need to know (IE guess) what is in between them.
(0.8 + 0.1) / 2 = 0.45 is our estimated interpolated value.

interpolation can be used as a kind of lowpass filter to round off the rough aliasing artifacts which crop up in FM synthesis when the generated harmonics go above nyquist.

at least that's my half-arsed understanding of it.

gustavo bravetti · Post by **gustavo bravetti** » Sat Mar 22, 2008 5:51 pm

Thanks again Angstrom,

Because my first question was about Operator's oversampling, and you told me to turn on High Quality settings on Operator to get oversampling:

oversampling came in Live 7 and must be activated in the Operator context menu.
I think it is 2x

...you make me thought that activating Operator's High Quality settings on the context menu (Antialias or Interpolation) some oversampling will be performed on the process.

I don't want oversampling to avoid aliasing artifacts, but to get the same definition on the higher harmonics that I'm having rendering Operator at 96Khz, as I said on the first post, I'm getting a noticeable difference on renders at 44.1 vs. 96Khz on higher freq harmonics, specially near Nyquist limit @ 44.1Khz.

Best,

PD. My english is a bit rusty excuse any misunderstand

Angstrom · Post by **Angstrom** » Sat Mar 22, 2008 8:11 pm

I just looked at the menu, the two entries are 'interpolation' and 'antialias'

now, I only got hold of Operator with Live7 and so I can;t speak for what was there before, but during the beat of Live 7 the terminology of the two were swapped around a few times. For a while it was 'high quality' , then it changed to something else to eliminate confusion. Obviously that didn't work in my case!

I think these days 'Anti-alias' is the oversampling mode, it is removing aliasing by raising the computation rate to 2xnyquist. So if your sound needs aliased frequencies, or it includes aliased frequencies and you raise the samplerate those aliased frequencies will disappear. Sometimes you don;t want that.

Hopefully I am right on this, I wish they had just called the 'high quality' modes 'oversampling' for clarity. Although not everyone understands the term, at least it is technically referring to something specific ... where 'high quality' is a bit like a nebulous claim on a cereal packet!

"new recipe, even more tasty!"

gustavo bravetti · Post by **gustavo bravetti** » Sun Mar 23, 2008 10:49 am

I see your point