mirror of
https://github.com/cookiengineer/audacity
synced 2025-05-02 08:39:46 +02:00
118 lines
4.4 KiB
Common Lisp
118 lines
4.4 KiB
Common Lisp
;nyquist plug-in
|
|
;version 3
|
|
;type process
|
|
;categories "http://lv2plug.in/ns/lv2core#SpectralPlugin"
|
|
;name "Vocoder..."
|
|
;action "Processing Vocoder..."
|
|
|
|
;; vocoder.ny by Edgar-RFT
|
|
;; a bit of code added by David R. Sky
|
|
;; GUI update by Steve Daulton July 2012.
|
|
;; 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:
|
|
;; http://wiki.audacityteam.org/wiki/Nyquist_Plug-ins_Reference
|
|
|
|
;control dst "Distance: (1 to 120, default = 20)" real "" 20 1 120
|
|
;control mst "Output choice" choice "both channels, right only" 0
|
|
;control bands "Number of vocoder bands" int "" 40 10 240
|
|
;control track-vl "Amplitude of original audio (percent)" real "" 100 0 100
|
|
;control noise-vl "Amplitude of white noise (percent)" real "" 0 0 100
|
|
;control radar-vl "Amplitude of Radar Needles (percent)" real "" 0 0 100
|
|
;control radar-f "Frequency of Radar Needles (Hz)" real "" 30 1 100
|
|
|
|
; maybe the code once again has to be changed into _one_ local let-binding
|
|
; if you have lots of nyquist "[gc:" messages try this:
|
|
; (expand 100) ; gives Xlisp more memory but I have noticed no speed difference
|
|
|
|
; number of octaves between 20hz and 20khz
|
|
(setf octaves (/ (log 1000.0) (log 2.0)))
|
|
|
|
; convert octaves to number of steps (semitones)
|
|
(setf steps (* octaves 12.0))
|
|
|
|
; interval - number of steps per vocoder band
|
|
(setf interval (/ steps bands))
|
|
|
|
; Some useful calculations but not used in this plugin
|
|
|
|
; half tone distance in linear
|
|
; (print (exp (/ (log 2.0) 12)))
|
|
|
|
; octave distance in linear
|
|
; (print (exp (/ (log 1000.0) 40)))
|
|
|
|
; The Radar Wavetable
|
|
|
|
; make *radar-table* a global variable.
|
|
(setf contol-dummy *control-srate*) ; save old *control-srate*
|
|
(set-control-srate *sound-srate*)
|
|
(setf *radar-table* (pwl (/ 1.0 *control-srate*) 1.0 ; 1.0 after 1 sample
|
|
(/ 2.0 *control-srate*) 0.0 ; 0.0 after 2 samples
|
|
(/ 1.0 radar-f))) ; stay 0.0 until end of the period
|
|
(set-control-srate contol-dummy) ; restore *control-srate*
|
|
; make *radar-table* become a nyquist wavetable of frequency radar-f
|
|
(setf *radar-table* (list *radar-table* (hz-to-step radar-f) T))
|
|
|
|
; increase the volume of the audacity track in the middle of the slider
|
|
; the sqrt trick is something like an artifical db scaling
|
|
(setf track-vol (sqrt (/ track-vl 100.0)))
|
|
; decrease the volume of the white noise in the middle of the slider
|
|
; the expt trick is an inverse db scaling
|
|
(setf noise-vol (expt (/ noise-vl 100.0) 2.0))
|
|
; also increase the volume of the needles in the middle of the slider
|
|
(setf radar-vol (sqrt (/ radar-vl 100.0)))
|
|
|
|
; here you can switch the tracks on and off for bug tracking
|
|
|
|
; (setf radar-vol 0)
|
|
; (setf noise-vol 0)
|
|
; (setf track-vol 0)
|
|
|
|
; The Mixer
|
|
|
|
; calculate duration of audacity selection
|
|
(setf duration (/ len *sound-srate*))
|
|
|
|
; if track volume slider is less than 100 percent decrease track volume
|
|
(if (< track-vl 100) (setf s (vector (aref s 0) (scale track-vol (aref s 1)))))
|
|
|
|
; if radar volume slider is more than 0 percent add some radar needles
|
|
(if (> radar-vl 0) (setf s (vector (aref s 0) (sim (aref s 1)
|
|
(scale radar-vol (osc (hz-to-step radar-f) duration *radar-table*))))))
|
|
|
|
; if noise volume slider is more than 0 percent add some white noise
|
|
(if (> noise-vl 0) (setf s (vector (aref s 0) (sim (aref s 1)
|
|
(scale noise-vol (noise duration))))))
|
|
|
|
; The Vocoder
|
|
|
|
(defun vocoder ()
|
|
(let ((p (+ (hz-to-step 20) (/ interval 2.0))) ; midi step of 20 Hz + offset
|
|
f ; we can leave f initialized to NIL
|
|
(q (/ (sqrt 2.0) (/ octaves bands))) ; explanation still missing
|
|
(result 0)) ; must be initialized to 0 because you cannot sum to NIL
|
|
(dotimes (i bands)
|
|
(setf f (step-to-hz p))
|
|
(setf result (sum result
|
|
(bandpass2 (mult (lowpass8
|
|
(s-max (bandpass2 (aref s 0) f q)
|
|
(scale -1 (bandpass2 (aref s 0) f q))) (/ f dst))
|
|
(bandpass2 (aref s 1) f q)) f q)))
|
|
(setf p (+ p interval)))
|
|
result))
|
|
|
|
; The Program
|
|
|
|
(if (arrayp s) (let ()
|
|
(cond ((= mst 1) (vector (aref s 0) (setf (aref s 1) (vocoder))))
|
|
((= mst 0) (setf s (vocoder))))
|
|
(cond ((= mst 1) (setq peakamp (peak (aref s 1) ny:all)))
|
|
((= mst 0) (setq peakamp (peak s ny:all))))
|
|
(cond ((= mst 1) (vector (aref s 0) (setf (aref s 1)
|
|
(scale (/ 1.0 peakamp) (aref s 1)))))
|
|
((= mst 0) (setf s (scale (/ 1.0 peakamp) s))))
|
|
s))
|
|
|