mirror of
https://github.com/cookiengineer/audacity
synced 2025-04-29 15:19:44 +02:00
8f5629a2a6
Fixed some verification errors, Removed some redundant translation strings, Define manpage for rms.ny.
117 lines
4.3 KiB
Common Lisp
117 lines
4.3 KiB
Common Lisp
$nyquist plug-in
|
|
$version 4
|
|
$type process
|
|
$preview linear
|
|
$name (_ "Delay")
|
|
$manpage "Delay"
|
|
$debugbutton false
|
|
$action (_ "Applying Delay Effect...")
|
|
$author (_ "Steve Daulton")
|
|
$release 2.3.1
|
|
$copyright (_ "Released under terms of the GNU General Public License version 2")
|
|
|
|
|
|
;; Released under terms of the GNU General Public License version 2:
|
|
;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
|
|
;; based on 'Delay' by David R. Sky
|
|
;;
|
|
;; For information about writing and modifying Nyquist plug-ins:
|
|
;; https://wiki.audacityteam.org/wiki/Nyquist_Plug-ins_Reference
|
|
|
|
|
|
$control delay-type (_ "Delay type") choice ((_ "Regular")
|
|
("BouncingBall" (_ "Bouncing Ball"))
|
|
("ReverseBouncingBall" (_ "Reverse Bouncing Ball"))) 0
|
|
$control dgain (_ "Delay level per echo (dB)") real "" -6 -30 1
|
|
$control delay (_ "Delay time (seconds)") real "" 0.3 0 5
|
|
$control pitch-type (_ "Pitch change effect") choice (("PitchTempo" (_ "Pitch/Tempo"))
|
|
("LQPitchShift" (_ "Low-quality Pitch Shift"))) 0
|
|
$control shift (_ "Pitch change per echo (semitones)") real "" 0 -2 2
|
|
$control number (_ "Number of echoes") int "" 5 1 30
|
|
$control constrain (_ "Allow duration to change") choice ((_ "Yes")(_ "No")) 0
|
|
|
|
|
|
;; The default pitch shift effect is a simple resampling,
|
|
;; so both pitch and tempo of the delayed audio will change
|
|
;; [as in Audacity's Change Speed effect].
|
|
;; LQ Pitch Shift (Low Quality) changes the pitch without
|
|
;; changing the tempo, but the sound quality is not very good
|
|
;; and tends to cause a short echo effect which can be quite
|
|
;; noticeable on percussive sounds though may be acceptable
|
|
;; on other sounds.
|
|
|
|
|
|
;;; Anti-alias low pass filter
|
|
(defun lp-wall (sig freq)
|
|
(do ((count 0 (1+ count))
|
|
(freq (* 0.94 freq)))
|
|
((= count 10) sig)
|
|
(setf sig (lowpass8 sig freq))))
|
|
|
|
;;; Change speed
|
|
(defun change-speed (sig shift)
|
|
(if (= shift 0) ; no pitch shift
|
|
sig
|
|
(let ((ratio (expt 0.5 (/ shift 12.0)))) ; shift value as frequency ratio
|
|
(force-srate *sound-srate*
|
|
(stretch-abs ratio (sound sig))))))
|
|
|
|
;;; Pitch shift audio
|
|
(defun p-shift (sig shift)
|
|
(if (= shift 0) ; no pitch shift
|
|
sig
|
|
(let ((sig (force-srate 44100 sig)) ; pitshift quality best at 44100
|
|
; anti-alias filter frequency
|
|
(minrate (* 0.5 (min *sound-srate* 44100)))
|
|
(ratio (expt 0.5 (/ shift -12.0)))) ; shift value as frequency ratio
|
|
(force-srate *sound-srate* ; convert back to correct rate
|
|
(progv '(*sound-srate*) (list 44100) ; pitshift requires rates to match
|
|
(cond
|
|
((> shift 5) ; reduce aliasing
|
|
(pitshift (lp-wall sig (/ minrate ratio)) ratio 1))
|
|
((< shift -2)
|
|
(pitshift (hp sig 20) ratio 1)) ; reduce sub-sonic frequencies
|
|
(T (pitshift sig ratio 1))))))))
|
|
|
|
;;; Apply effects to echo
|
|
(defun modify (sig num gain shift p-type)
|
|
(let ((gain (db-to-linear (* num gain)))
|
|
(shift (* num shift)))
|
|
(if (= p-type 0)
|
|
(mult gain (change-speed sig shift))
|
|
(mult gain (p-shift sig shift)))))
|
|
|
|
;;; Compute echoes
|
|
(defun delays (sound gain delay shift num type mod)
|
|
(let ((echo (s-rest 0)))
|
|
(do ((count 1 (1+ count))
|
|
(dly 0))
|
|
((> count num)(sim echo sound))
|
|
(setq dly
|
|
(case type
|
|
(0 (+ dly delay))
|
|
(1 (+ dly (* delay (- (1+ num) count))))
|
|
(2 (+ dly (* delay count)))))
|
|
(setf echo (sim
|
|
(at 0 (cue echo))
|
|
(at-abs dly
|
|
(cue (modify sound count gain shift mod))))))))
|
|
|
|
(defun constrain-abs (sig dur)
|
|
(extract-abs 0 dur (cue sig)))
|
|
|
|
|
|
(let* ((delay (if (= delay-type 0)
|
|
delay
|
|
(/ delay number)))
|
|
(output (multichan-expand #'delays *track*
|
|
dgain
|
|
delay
|
|
shift
|
|
number
|
|
delay-type
|
|
pitch-type)))
|
|
(if (= constrain 1)
|
|
(multichan-expand #'constrain-abs output (get-duration 1))
|
|
output))
|