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audacity/plug-ins/SpectralEditParametricEQ.ny

60 lines
2.3 KiB
Common Lisp

;nyquist plug-in
;version 4
;type process
;preview enabled
;name "Spectral edit parametric EQ..."
;action "Filtering..."
;author "Paul Licameli"
;copyright "Released under terms of the GNU General Public License version 2"
;; SpectralEditParametricEQ.ny by Paul Licameli, November 2014.
;; Updated to version 4 by Steve Daulton November 2014.
;; Released under terms of the GNU General Public License version 2:
;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
;control control-gain "Gain (dB)" real "" 0 -24 24
(setf control-gain (min 24 (max -24 control-gain))) ; excessive settings may crash
(defun wet (sig gain)
(let ((f0 (get '*selection* 'low-hz))
(f1 (get '*selection* 'high-hz))
(fc (get '*selection* 'center-hz))
(bw (get '*selection* 'bandwidth)))
(cond
((not (or f0 f1))
(throw 'debug-message (format nil "~aPlease select frequencies." p-err)))
((not f0)
(throw 'debug-message (format nil "~aLow frequency is undefined." p-err)))
((not f1)
(throw 'debug-message (format nil "~aHigh frequency is undefined." p-err)))
((= bw 0)
(throw 'debug-message (format nil "~aBandwidth is zero.\nSelect a frequency range." p-err)))
(t (eq-band sig fc gain (/ bw 2))))))
(defun result (sig)
(let*
((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)))
(sum (prod env (wet sig control-gain)) (prod (diff 1.0 env) sig))))
(cond
((not (get '*TRACK* 'VIEW)) ; 'View is NIL during Preview
(setf p-err (format nil "This effect requires a frequency selction in the~%~
'Spectrogram' or 'Spectrogram (log f)' track view.~%~%"))
(catch 'debug-message
(multichan-expand #'result *track*)))
((string-not-equal (get '*TRACK* 'VIEW) "spectrogram" :end1 4 :end2 4)
"Use this effect in the 'Spectrogram'\nor 'Spectrogram (log f)' view.")
(T (setf p-err "")
(if (= control-gain 0) ; Allow dry preview
"Gain is zero. Nothing to do."
(catch 'debug-message
(multichan-expand #'result *track*)))))