mirror of
https://github.com/cookiengineer/audacity
synced 2025-04-30 07:39:42 +02:00
67 lines
2.6 KiB
Common Lisp
67 lines
2.6 KiB
Common Lisp
;nyquist plug-in
|
|
;version 4
|
|
;type process spectral
|
|
$name (_"Spectral edit multi tool")
|
|
;manpage "Spectral_edit_multi_tool"
|
|
$action (_"Filtering...")
|
|
$author (_"Paul Licameli")
|
|
$copyright (_"Released under terms of the GNU General Public License version 2")
|
|
|
|
;; SpectralEditMulti.ny by Paul Licameli, November 2014.
|
|
;; Updated by Steve Daulton 2014 / 2015.
|
|
;; Released under terms of the GNU General Public License version 2:
|
|
;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
|
|
|
|
(defun wet (sig f0 f1 fc)
|
|
(cond
|
|
((not f0) (highpass2 sig f1))
|
|
((not f1) (lowpass2 sig f0))
|
|
(T (let ((q (/ fc (- f1 f0))))
|
|
(notch2 sig fc q)))))
|
|
|
|
(defun result (sig)
|
|
(let* ((f0 (get '*selection* 'low-hz))
|
|
(f1 (get '*selection* 'high-hz))
|
|
(fc (get '*selection* 'center-hz))
|
|
(bw (get '*selection* 'bandwidth))
|
|
(tn (truncate len))
|
|
(rate (snd-srate sig))
|
|
(transition (truncate (* 0.01 rate))) ; 10 ms
|
|
(t1 (min transition (/ tn 2))) ; fade in length (samples)
|
|
(t2 (max (- tn transition) (/ tn 2))) ; length before fade out (samples)
|
|
(breakpoints (list t1 1.0 t2 1.0 tn))
|
|
(env (snd-pwl 0.0 rate breakpoints)))
|
|
(cond
|
|
((not (or f0 f1)) ; This should never happen for a 'spectral' effect.
|
|
(throw 'error-message
|
|
(format nil (_"~aPlease select frequencies.") p-err)))
|
|
((and f0 f1 (= f0 f1))
|
|
(throw 'error-message
|
|
(format nil (_"~aBandwidth is zero (the upper and lower~%~
|
|
frequencies are both ~a Hz).~%~
|
|
Please select a frequency range.")
|
|
p-err f0)))
|
|
;; Biqud filter fails if centre frequency is very low and bandwidth very high.
|
|
;; 'Magic numbers' 10 Hz and 10 octaves are experimental.
|
|
((and f0 (< f0 10) (or (not bw)(> bw 10)))
|
|
(throw 'error-message
|
|
(format nil (_"~aNotch filter parameters cannot be applied.~%~
|
|
Try increasing the low frequency bound~%~
|
|
or reduce the filter 'Width'.")
|
|
p-err)))
|
|
;; low pass frequency is above Nyquist so do nothing
|
|
((and (not f1) (>= f0 (/ *sound-srate* 2.0)))
|
|
nil)
|
|
;; notch frequency is above Nyquist so do nothing
|
|
((and f0 f1 (>= fc (/ *sound-srate* 2.0)))
|
|
nil)
|
|
;; high-pass above Nyquist so fade to silence
|
|
((and (not f0) (>= f1 (/ *sound-srate* 2.0)))
|
|
(mult sig (diff 1.0 env)))
|
|
(T (sum (prod env (wet sig f0 f1 fc))
|
|
(prod (diff 1.0 env) sig))))))
|
|
|
|
(catch 'error-message
|
|
(setf p-err (_"Error.\n"))
|
|
(multichan-expand #'result *track*))
|