audacia/plug-ins/SpectralEditParametricEQ.ny

71 lines
2.8 KiB
Common Lisp

$nyquist plug-in
$version 4
$type process spectral
$preview linear
$name (_ "Spectral edit parametric EQ")
$manpage "Spectral_edit_parametric_EQ"
$action (_ "Filtering...")
$author (_ "Paul Licameli")
$release 2.3.0
$copyright (_ "Released under terms of the GNU General Public License version 2")
;; SpectralEditParametricEQ.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
;;
;; For information about writing and modifying Nyquist plug-ins:
;; https://wiki.audacityteam.org/wiki/Nyquist_Plug-ins_Reference
$control control-gain (_ "Gain (dB)") real "" 0 -24 24
(defun wet (sig gain fc bw)
(eq-band sig fc gain (/ bw 2)))
(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)))
((not f0)
(throw 'error-message (format nil (_ "~aLow frequency is undefined.") p-err)))
((not f1)
(throw 'error-message (format nil (_ "~aHigh frequency is undefined.") p-err)))
((and fc (= fc 0))
(throw 'error-message (format nil (_ "~aCenter frequency must be above 0 Hz.") p-err)))
((and f1 (> f1 (/ *sound-srate* 2)))
(throw 'error-message
(format nil (_ "~aFrequency selection is too high for track sample rate.~%~
For the current track, the high frequency setting cannot~%~
be greater than ~a Hz")
p-err (/ *sound-srate* 2))))
((and bw (= bw 0))
(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)))
;; If centre frequency band is above Nyquist, do nothing.
((and fc (>= fc (/ *sound-srate* 2.0)))
nil)
(t (sum (prod env (wet sig control-gain fc bw))
(prod (diff 1.0 env) sig))))))
(catch 'error-message
(setf p-err (format nil (_ "Error.~%")))
(if (= control-gain 0)
nil ; Do nothing
(multichan-expand #'result *track*)))