audacia/plug-ins/rissetdrum.ny

92 lines
2.8 KiB
Common Lisp

$nyquist plug-in
$version 4
$type generate
$preview linear
$i18n-hint named for Jean-Claude Risset (silent t)
$name (_ "Risset Drum")
$manpage "Risset_Drum"
$action (_ "Generating Risset Drum...")
$author (_ "Steven Jones")
$release 2.3.0
$copyright (_ "Released under terms of the GNU General Public License version 2")
;; rissetdrum.ny by Steven Jones, after Jean Claude Risset.
;; Updated by Steve Daulton July 2012 and May 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 freq (_ "Frequency (Hz)") real "" 100 50 2000
$control decay (_ "Decay (seconds)") real "" 2 0.1 60
$control cf (_ "Center frequency of noise (Hz)") real "" 500 100 5000
$control bw (_ "Width of noise band (Hz)") real "" 400 10 1000
$control noise (_ "Amount of noise in mix (percent)") real "" 25 0 100
$control gain (_ "Amplitude (0 - 1)") real "" 0.8 0 1
(defun sanitise (val minx maxx)
(min (max val minx) maxx))
;; Not required with validation in Audacity 2.1.1 but left
;; for compatibility.
(setq freq (sanitise freq 1 (/ *sound-srate* 2)))
(setq decay (sanitise decay 0.1 600))
(setq cf (sanitise cf 1 (/ *sound-srate* 2)))
(setq bw (sanitise bw 10 1000))
(setq noise (sanitise (/ noise 100) 0 1))
(setq gain (sanitise gain 0 1))
;; Get length of preview
(setq pdur
(if (get '*track* 'view) ;NIL if preview
decay
(get '*project* 'preview-duration)))
(setq *rdrum-table*
(list
(mult 0.17
(sum
(scale 1.00 (build-harmonic 10 2048))
(scale 1.50 (build-harmonic 16 2048))
(scale 2.00 (build-harmonic 22 2048))
(scale 1.50 (build-harmonic 23 2048))))
(hz-to-step 1) t))
(defun log2 (n)
(/ (log (float n))(log 2.0)))
(defun percussion-env (decay)
(let* ((half-life (expt 2.0 (- (log2 decay) 3))))
(exp-dec 0 half-life decay)))
(defun risset-drum (freq decay cf bw noise-gain)
(let* ((decay2 (* decay 0.50))
(low-note (* freq 0.10))
(tone-gain (- 1 noise-gain)))
(setf pink (lowpass6 (noise decay2) bw))
(setf rdrum
(mult tone-gain
(osc (hz-to-step low-note) decay2 *rdrum-table*)))
(setf noise-band
(mult noise-gain
(sine (hz-to-step cf) decay2)
pink))
(sum
(mult
(percussion-env decay2)
(sum noise-band rdrum ))
(mult tone-gain
(percussion-env decay)
(sine (hz-to-step freq) decay)))))
;; Generate and normalize
(let* ((output (risset-drum freq decay cf bw noise))
(output (extract-abs 0 pdur output)) ; shorten if necessary for preview.
(peakval (peak output ny:all)))
(scale (/ gain peakval) output))