mirror of
https://github.com/cookiengineer/audacity
synced 2025-04-30 07:39:42 +02:00
133 lines
4.4 KiB
Common Lisp
133 lines
4.4 KiB
Common Lisp
;nyquist plug-in
|
|
;version 3
|
|
;type process
|
|
;categories "http://lv2plug.in/ns/lv2core#DelayPlugin"
|
|
;name "Delay..."
|
|
;action "Performing Delay Effect..."
|
|
;info "by Roger Dannenberg, modified by David R. Sky\nReleased under terms of the GNU General Public License Version 2 \nDelay type: 'bouncing ball' makes the echoes occur increasingly close\ntogether (faster); 'reverse bouncing ball' makes them occur increasingly far\napart (slower). In either bouncing ball effect, delay time is not time between\nechoes but the * maximum * delay time in bounces.\nApplying delay can cause clipping (distortion), especially when reducing the\ndecay value and using more echoes. It's normally best to use Effect > Amplify\nto set the peak amplitude to -6 dB before using delay.
|
|
|
|
;control delay-type "Delay type" choice "regular,bouncing ball,reverse bouncing ball" 0
|
|
;control decay "Decay amount [dB; negative value increases volume]" real "" 6 -1 24
|
|
;control delay "Delay time [seconds]" real "" 0.5 0 5
|
|
;control shift "Pitch change per echo [semitones; negative value = lower, 0 is off]" real "" 0 -2 2
|
|
;control count "Number of echoes" int "" 5 1 30
|
|
|
|
; Delay by Roger B. Dannenberg
|
|
; modified by David R. Sky October 2007,
|
|
; adding negative decay values, which gives delay effect
|
|
; increasing volume with each delay; and adding
|
|
; bouncing ball and reverse bouncing ball delay effects
|
|
; and pitch [semitone] change with each echo.
|
|
; modified by Richard Ash January 2008, removing all
|
|
; normalization functions.
|
|
|
|
; Note by Roger Dannenberg: this effect will use up memory proportional to
|
|
; delay * count, since that many samples must be buffered
|
|
; before the first block is freed.
|
|
|
|
; initialize empty error message
|
|
(setf error-msg "")
|
|
|
|
|
|
; check function: returns 1 on error
|
|
(defun check (arg min max)
|
|
(if (and (>= arg min) (<= arg max))
|
|
0 1))
|
|
|
|
|
|
; checking for erroneous user-input values:
|
|
(setf error-msg (if (= (check decay -1 24) 0)
|
|
error-msg
|
|
(strcat error-msg
|
|
(format nil "Decay value '~a' outside valid range -1.0 to 24.0 dB.
|
|
" decay))))
|
|
|
|
(setf error-msg (if (= (check delay 0 5) 0)
|
|
error-msg
|
|
(strcat error-msg
|
|
(format nil "Delay value '~a' outside valid range 0.0 to 5.0 seconds.
|
|
" delay))))
|
|
|
|
(setf error-msg (if (= (check shift -2 2) 0)
|
|
error-msg
|
|
(strcat error-msg
|
|
(format nil "Pitch change value '~a' outside valid range -2.0 to 2.0 semitones.
|
|
" shift))))
|
|
|
|
(setf error-msg (if (= (check count 1 30) 0)
|
|
error-msg
|
|
(strcat error-msg
|
|
(format nil "Number of echoes '~a' outside valid range 1 to 30 echoes.
|
|
" count))))
|
|
; finished error-checking
|
|
|
|
; if error-msg is longer than 0 characters,
|
|
; prepend opening message
|
|
(setf error-msg (if (> (length error-msg) 0)
|
|
(strcat "Error -\n\nYou have input at least one invalid value:
|
|
" error-msg)
|
|
error-msg))
|
|
|
|
(cond ; 1
|
|
((> (length error-msg) 0)
|
|
(format nil "~a" error-msg))
|
|
|
|
(t ; no input errors, perform delay
|
|
|
|
; convert shift value to a value the Nyquist code understands
|
|
(setf shift (expt 0.5 (/ shift 12.0)))
|
|
|
|
; for bouncing ball effects, set delay time to delay time/count
|
|
(setf delay (if (> delay-type 0)
|
|
(/ delay count) delay))
|
|
|
|
|
|
|
|
; function to stretch audio
|
|
(defun change (sound shift)
|
|
(if (arrayp sound)
|
|
(vector
|
|
(force-srate 44100 (stretch-abs shift (sound (aref sound 0))))
|
|
(force-srate 44100 (stretch-abs shift (sound (aref sound 1)))))
|
|
(force-srate 44100 (stretch-abs shift (sound sound)))))
|
|
|
|
|
|
(cond ; 2
|
|
((= delay-type 0) ; regular delay
|
|
; delay function
|
|
(defun delays (s decay delay count shift)
|
|
(if (= count 0) (cue s)
|
|
(sim (cue s)
|
|
(loud decay (at delay (delays (change s shift)
|
|
decay delay (- count 1) shift))))))
|
|
|
|
(stretch-abs 1 (delays s (- 0 decay) delay count shift)))
|
|
|
|
|
|
((= delay-type 1) ; bouncing ball delay
|
|
; bouncing ball delay function
|
|
(defun bounces (s decay delay count shift)
|
|
(if (= count 0) (cue s)
|
|
(sim (cue s)
|
|
(loud decay (at (mult delay count)
|
|
(bounces (change s shift) decay delay
|
|
(- count 1) shift))))))
|
|
|
|
(stretch-abs 1 (bounces s (- 0 decay) delay count shift)))
|
|
|
|
|
|
((= delay-type 2) ; reverse bouncing ball delay
|
|
; reverse bouncing ball delay function
|
|
(defun revbounces (s decay delay count revcount shift)
|
|
(if (= count 0) (cue s)
|
|
(sim (cue s)
|
|
(loud decay (at (mult delay (- revcount count))
|
|
(revbounces (change s shift) decay delay
|
|
(- count 1 ) revcount shift))))))
|
|
|
|
(setf revcount (1+ count))
|
|
(stretch-abs 1 (revbounces s (- 0 decay) delay count revcount shift)))
|
|
) ; end cond2, different delay effect choices
|
|
) ; end cond1 t
|
|
) ; end cond 1
|