rsc3/doc/help/ugen/fft/pvcollect.help.scm

61 lines
1.8 KiB
Scheme

;; (pvcollect chain numframes func frombin tobin zeroothers)
;; Process each bin of an fft chain separately.
;; pvcollect applies function func to each bin of an fft chain. func
;; should be a function that takes magnitude, phase, index as inputs
;; and returns a resulting [magnitude, phase].
;; The "index" is the integer bin number, starting at 0 for DC. You
;; can optionally ignore the phase and only return a single
;; (magnitude) value, in which case the phase is assumed to be left
;; unchanged.
;; frombin, tobin, and zeroothers are optional arguments which limit
;; the processing to a specified integer range of fft bins. If
;; zeroothers is set to 1 then bins outside of the range being
;; processed are silenced.
;; Note that this procedure can be relatively CPU-heavy, depending on
;; how you use it.
(define no-op
(lambda (m p _)
(list m p)))
(define rand-phase
(lambda (m p _)
(list m (rand 0 3.14))))
(define noise-phase
(lambda (m p _)
(list m (lin-lin (lf-noise0 kr 3) -1 1 0 3.14))))
(define combf
(lambda (m p i)
(list (if (= (modulo i 7) 0) m 0) p)))
(define noise-mag
(lambda (m p _)
(list (mul (gt (lf-noise0 kr 10) 0) m) p)))
(define spectral-delay
(lambda (m p _)
(let ((v (lin-lin (lf-par kr 0.5 0) -1 1 0.1 1)))
(list (add m (delay-n m 1 v)) p))))
(define (bpf-sweep nf)
(lambda (m p i)
(let ((e (u:abs (sub i (lin-lin (lf-par kr 0.1 0) -1 1 2 (/ nf 20))))))
(list (mul (lt e 10) m) p))))
(with-sc3
(lambda (fd)
(async fd (b-alloc 10 1024 1))
(async fd (b-alloc-read 11 "/home/rohan/audio/metal.wav" 0 0))))
(let* ((nf 1024)
(i (play-buf 1 11 (buf-rate-scale kr 11) 1 0 1))
(c1 (fft* 10 i))
(c2 (pvcollect c1 nf spectral-delay 0 250 0)))
(audition (out 0 (mul 0.1 (ifft* c2)))))