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spectral transformations and rec array
Posted: 17 Jul 2020, 09:15
by Zucchi
Hi,
I would like to know how would you proceed to record and playback an array of values ? The goal is to do some spectral transforms on audio flow with FFT.
I tried to record the output of [FFT forward] into a stereo [Audio Sampler Recorder] (one chan for real part and other one for imaginary) but it's not really efficient and I'm limited to the usine bloc size for the window size of my FFT. I'm also not sure about how the conversion works between real values and dB inside the recorder.
Z.
Re: spectral transformations and rec array
Posted: 18 Jul 2020, 00:23
by SylvainT
Hello,
The FFT forward output is an array, so impossible to record with a sampler, and for sure you'll be limited to the usine bloc size for the window size of your FFT.
It will be difficult to record FFT, so many bins to rec, you'll need huge arrays.
Why dont you use a sampler recorder before the FFT manipulation.
Sylvain
Re: spectral transformations and rec array
Posted: 19 Jul 2020, 02:03
by x.iso
yeah, it would make sense to record sample instead, FFT is designed for real-time processing after all. and Usine is not really designed to do 'offline' processing, as there's no audio export as well.
Re: spectral transformations and rec array
Posted: 19 Jul 2020, 11:21
by Zucchi
Hi,
I wanted to record the different bins for a spectral freeze effect. I wanted to do some translations and rec a small window to read in random orders added with a small amount of noise on each real bin. That's why I wanted to use some arrays for the maths.
Re: spectral transformations and rec array
Posted: 19 Jul 2020, 12:30
by SylvainT
Make polyphonic subpatch with arrays to save your differents states and then recall them.
Be carefull with FFT manipulations, it could be very expensive in CPU consumption. You'll had to trigg your calculations with the bins size.
Re: spectral transformations and rec array
Posted: 20 Jul 2020, 10:20
by x.iso
Zucchi wrote: ↑19 Jul 2020, 11:21
Hi,
I wanted to record the different bins for a spectral freeze effect. I wanted to do some translations and rec a small window to read in random orders added with a small amount of noise on each real bin. That's why I wanted to use some arrays for the maths.
There's example patch in the library called 'Spectral Average', perhaps that's what you're looking for.
Re: spectral transformations and rec array
Posted: 21 Aug 2020, 11:43
by oli_lab
Hi !
have a look at my module "store array 512x2048" in the oli_lab pack/datalab/array
it provides what you need to store array from an FFT then to retrive stored arrays and do morphing.
see also the example included in the pack.
cheers