1$nyquist plug-in 2$version 4 3$type process spectral 4$preview linear 5$name (_ "Spectral edit parametric EQ") 6$manpage "Spectral_edit_parametric_EQ" 7$action (_ "Filtering...") 8$author (_ "Paul Licameli") 9$release 2.3.0 10$copyright (_ "Released under terms of the GNU General Public License version 2") 11 12;; SpectralEditParametricEQ.ny by Paul Licameli, November 2014. 13;; Updated by Steve Daulton 2014 / 2015. 14 15;; Released under terms of the GNU General Public License version 2: 16;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html 17;; 18;; For information about writing and modifying Nyquist plug-ins: 19;; https://wiki.audacityteam.org/wiki/Nyquist_Plug-ins_Reference 20 21$control control-gain (_ "Gain (dB)") real "" 0 -24 24 22 23(defun wet (sig gain fc bw) 24 (eq-band sig fc gain (/ bw 2))) 25 26(defun result (sig) 27 (let* 28 ((f0 (get '*selection* 'low-hz)) 29 (f1 (get '*selection* 'high-hz)) 30 (fc (get '*selection* 'center-hz)) 31 (bw (get '*selection* 'bandwidth)) 32 (tn (truncate len)) 33 (rate (snd-srate sig)) 34 (transition (truncate (* 0.01 rate))) ; 10 ms 35 (t1 (min transition (/ tn 2))) ; fade in length (samples) 36 (t2 (max (- tn transition) (/ tn 2))) ; length before fade out (samples) 37 (breakpoints (list t1 1.0 t2 1.0 tn)) 38 (env (snd-pwl 0.0 rate breakpoints))) 39 (cond 40 ((not (or f0 f1)) ; This should never happen for a 'spectral' effect. 41 (throw 'error-message (format nil (_ "~aPlease select frequencies.") p-err))) 42 ((not f0) 43 (throw 'error-message (format nil (_ "~aLow frequency is undefined.") p-err))) 44 ((not f1) 45 (throw 'error-message (format nil (_ "~aHigh frequency is undefined.") p-err))) 46 ((and fc (= fc 0)) 47 (throw 'error-message (format nil (_ "~aCenter frequency must be above 0 Hz.") p-err))) 48 ((and f1 (> f1 (/ *sound-srate* 2))) 49 (throw 'error-message 50 (format nil (_ "~aFrequency selection is too high for track sample rate.~%~ 51 For the current track, the high frequency setting cannot~%~ 52 be greater than ~a Hz") 53 p-err (/ *sound-srate* 2)))) 54 ((and bw (= bw 0)) 55 (throw 'error-message 56 (format nil (_ "~aBandwidth is zero (the upper and lower~%~ 57 frequencies are both ~a Hz).~%~ 58 Please select a frequency range.") 59 p-err f0))) 60 ;; If centre frequency band is above Nyquist, do nothing. 61 ((and fc (>= fc (/ *sound-srate* 2.0))) 62 nil) 63 (t (sum (prod env (wet sig control-gain fc bw)) 64 (prod (diff 1.0 env) sig)))))) 65 66(catch 'error-message 67 (setf p-err (format nil (_ "Error.~%"))) 68 (if (= control-gain 0) 69 nil ; Do nothing 70 (multichan-expand #'result *track*))) 71