我需要使用Audacity将恒定dB级别的白噪声添加到批量声音文件中。 Generate插件'Noise'基本上就是我正在寻找的，但它不能用于为链中的文件添加噪声，因为它会覆盖每个文件而不是向其添加白噪声。有一个效果插件'添加噪音'也非常接近我需要的，但白噪声是每个文件中总噪声的百分比，而不是以恒定的dB级别添加到每个文件。
我正在尝试使用“Nyquist Prompt”编辑“添加噪音”插件的代码，以便将噪音级别设置从百分比更改为dB，但对于新代码应该是什么不知所措。我认为我需要更改的2行是第9行和第13行，但同样，我并不完全确定。 “添加噪音”插件来自Audacity forum。
;nyquist plug-in
;version 3
;type process
;categories "http://lv2plug.in/ns/lv2core#GeneratorPlugin"
;name "Add Noise ..."
;action "Adding Selected Noise ..."
;info "by 'Steve Daulton.\nReleased under GPL V2."
;control mix "Noise mix (%)" real "" 20 0 100
;control type "Type of Noise" choice "White,Pink,Crackle,Wind" 0
(setf mix (/ mix 100))
;;; Wind noise by Robert J. H.
(defun wind (gust speed)
(defmacro contour (scale offset min-wind max-wind)
`(sum ,offset
(mult ,scale
(s-abs (reson (noise) ,min-wind ,max-wind 1)))))
(mult 2
(contour 300 0.7 gust speed)
(sim (reson (noise) 593 80 2)
(reson (noise) (contour 300000 300 gust speed) 200 2))))
;;; pink noise
(defun pink ()
(setf params (list '(25600 -4 2.0) '(12800 -3 2.0) '(6400 -2 2.0) '(3200 -1 2.0)
'(1600 0 2.0) '(800 1 2.0) '(400 2 2.0) '(200 3 2.0) '(100 4 2.0)
'(50 5 2.0) '(25 6 2.0) '(12.5 7 2.0)))
(force-srate *sound-srate*
(sound-srate-abs 96000
(progn
(setf colour-noise (noise))
(dotimes (i (length params))
(setf colour-noise
(eq-band colour-noise
(first (nth i params))
(second (nth i params))
(third (nth i params)))))
(lowpass2 colour-noise 25600 0.5)))))
;;; crackle
(defun crackle (density)
(defun clicks ()
(let ((mynoise (mult 1.33 (lp (noise) 1000)))
(density (max
(- 0.9 density)
0.1)))
(clip
(mult (/ (- 1 density))
(diff (s-max mynoise density) density))
1.0)))
(sum (clicks) (mult -1 (clicks))))
;;; mix two mono sounds
(defun mono-mix (snd1 snd2 mix)
(sim (mult (- 1 mix) snd1)
(mult mix snd2)))
;; select the type of noise
(setf my-noise
(case type
(0 (noise))
(1 (pink))
(2 (crackle 0.4))
(t (let ((gustiness 0.2)
(wind-speed 0.2))
(wind gustiness wind-speed)))))
; stereo mix sound and noise
(multichan-expand #'mono-mix s my-noise mix)
答案 0 :(得分：0)
;nyquist plug-in
;version 3
;type process
;categories "http://lv2plug.in/ns/lv2core#GeneratorPlugin"
;name "Add Noise ..."
;action "Adding Selected Noise ..."
;info "by 'Steve Daulton.\nReleased under GPL V2."
;control level "Noise level (0 to 1)" real "" 0.5 0 1
;control type "Type of Noise" choice "White,Pink,Crackle,Wind" 0
(setf mix level)
;;; Wind noise by Robert J. H.
(defun wind (gust speed)
(defmacro contour (scale offset min-wind max-wind)
`(sum ,offset
(mult ,scale
(s-abs (reson (noise) ,min-wind ,max-wind 1)))))
(mult 2
(contour 300 0.7 gust speed)
(sim (reson (noise) 593 80 2)
(reson (noise) (contour 300000 300 gust speed) 200 2))))
;;; pink noise
(defun pink ()
(setf params (list '(25600 -4 2.0) '(12800 -3 2.0) '(6400 -2 2.0) '(3200 -1 2.0)
'(1600 0 2.0) '(800 1 2.0) '(400 2 2.0) '(200 3 2.0) '(100 4 2.0)
'(50 5 2.0) '(25 6 2.0) '(12.5 7 2.0)))
(force-srate *sound-srate*
(sound-srate-abs 96000
(progn
(setf colour-noise (noise))
(dotimes (i (length params))
(setf colour-noise
(eq-band colour-noise
(first (nth i params))
(second (nth i params))
(third (nth i params)))))
(lowpass2 colour-noise 25600 0.5)))))
;;; crackle
(defun crackle (density)
(defun clicks ()
(let ((mynoise (mult 1.33 (lp (noise) 1000)))
(density (max
(- 0.9 density)
0.1)))
(clip
(mult (/ (- 1 density))
(diff (s-max mynoise density) density))
1.0)))
(sum (clicks) (mult -1 (clicks))))
;;; mix two mono sounds
(defun mono-mix (snd1 snd2 mix)
(sim snd1
(mult mix snd2)))
;; select the type of noise
(setf my-noise
(case type
(0 (noise))
(1 (pink))
(2 (crackle 0.4))
(t (let ((gustiness 0.2)
(wind-speed 0.2))
(wind gustiness wind-speed)))))
; stereo mix sound and noise
(multichan-expand #'mono-mix s my-noise mix)`