This file is indexed.

/usr/share/audacity/plug-ins/adjustable-fade.ny is in audacity-data 2.1.2-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
;nyquist plug-in
;version 4
;type process
;preview linear
;preview selection
;categories "http://lv2plug.in/ns/lv2core#MixerPlugin"
;name "Adjustable Fade..."
;action "Applying Fade..."
;author "Steve Daulton"
;copyright "Released under terms of the GNU General Public License version 2"

;; adjustable-fade.ny by Steve Daulton Dec 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 type "Fade Type" choice "Fade Up,Fade Down,S-Curve Up,S-Curve Down" 0
;control curve "Mid-fade Adjust (%)" real "" 0 -100 100
;control units "Start/End as" choice "% of Original,dB Gain" 0 
;control gain-string-0 "Start (or end)" string "" "0" ""
;control gain-string-1 "End (or start)" string "" "100" ""
;control preset "   Handy Presets\n(override controls)" choice "None Selected,Linear In,Linear Out,Exponential In,Exponential Out,Logarithmic In,Logarithmic Out,Rounded In,Rounded Out,Cosine In,Cosine Out,S-Curve In,S-Curve Out" 0


(defun get-input (sig)
"Preview takes the entire selection so that we know the correct
selection length, but preview only needs to process preview length."
  (if (get '*track* 'view)  ;NIL if preview
      sig
      (multichan-expand #'trim-input sig)))

(defun trim-input (sig)
"Trim input when previewing."
  (let ((dur (min (get-duration 1)
                  (get '*project* 'preview-duration))))
    (setf sig (extract-abs 0 dur *track*))))


(setq err "")
; bad things may happen outside of the slider range.
(setq curve (min 1 (max -1 (/ curve 100.0))))

;;; Convert string to value
(defun string-to-val (string)
  (setq val-array 
    (read (make-string-input-stream (format nil "(~a)" string))))
  (if (and (= (length val-array) 1)
           (numberp (car val-array)))
      (let ((val (float (car val-array))))
        (case units
          (0 (/ val 100))
          (t (db-to-linear val))))))

;;; invalid string error
(defun invalid-string (x y)
  (unless x 
    (setf err (format nil "~aYou entered \"~a\"~%~
      \"Start (or end):\" must be one number.~%"
      err
      gain-string-0)))
  (unless y
    (setf err (format nil "~aYou entered \"~a\"~%~
      \"End (or start):\" must be one number.~%"
      err gain-string-1)))
  err)

;;; invalid values
(defun check-values (x y)
  (when (or (< x 0)(< y 0))
    (setf err (format nil "~a% values cannot be negative.~%" err))))

;;; select and apply fade
(defun fade (sig type curve g0 g1)
  (mult (get-input sig)
    (case preset
      (0  (case type                  ; Custom fade
            (0 (simple (min g0 g1) (max g0 g1) curve))
            (1 (simple (max g0 g1) (min g0 g1) curve))
            (2 (raised-cos (min g0 g1)(max g0 g1) curve))
            (T (raised-cos (max g0 g1) (min g0 g1) curve))))
      (1  (linear 0 1))               ; Linear In
      (2  (linear 1 0))               ; Linear Out
      (3  (log-exp-curve -60 0))      ; Exponential In
      (4  (log-exp-curve -60 1))      ; ExponentialOut
      (5  (log-exp-curve 15.311 0))   ; Logarithmic In
      (6  (log-exp-curve 15.311 1))   ; Logarithmic Out
      (7  (simple-curve 0 1 0.5))     ; Rounded In
      (8  (simple-curve 1 0 0.5))     ; Rounded Out
      (9  (cosine-curve 0 1))         ; Cosine In
      (10 (cosine-curve 1 0))         ; Cosine Out
      (11 (raised-cos 0 1 0.0))       ; S-Curve In
      (t  (raised-cos 1 0 0.0)))))    ; S-Curve Out

;;; Simple Curve:
;;; Use cosine for + values and linear for -ve.
(defun simple (g0 g1 curve)
  (cond 
    ((= g0 g1) g0)                    ; amplify
    ((and (> curve 0)(< curve 0.5))   ; +ve curve less than 0.5, lin to cosine
      (let ((curve (* curve 2)))
        (sim 
          (mult (- 1 curve)
            (scale-curve g0 g1 (linear g0 g1)))           ; linear
          (mult curve
            (scale-curve g0 g1 (cosine-curve g0 g1))))))  ; cosine curve
    ((> curve 0)
      (cos-curve g0 g1 (- 1.5 curve)))                    ; +ve curve > 0.5
    (t (simple-curve g0 g1 (- 1 (* 2 curve))))))          ; -ve curve

;;; linear fade to the power of pow
(defun simple-curve (g0 g1 pow)
  (curve-adjust g0 g1 pow
    (linear g0 g1)))

;;; cosine fade to the power of pow
(defun cos-curve (g0 g1 pow)
  (curve-adjust g0 g1 pow
    (cosine-curve g0 g1)))

(defun curve-adjust (g0 g1 pow env)
  (scale-curve g0 g1
    (if (= pow 1)
        env
        (snd-exp
          (mult pow
            (snd-log env))))))

;;; scale curves to min, max
(defun scale-curve (g0 g1 env)
  (sum (min g0 g1)
    (mult (abs (- g0 g1)) env)))

;;; cosine curve
(defun cosine-curve (g0 g1)
  (let ((step (hz-to-step (/ 0.25 (get-duration 1))))
        (phase (if (> g0 g1) 90 0)))
    (osc step 1 *sine-table* phase)))

;;; linear fade in, out
(defun linear (g0 g1)
  (control-srate-abs *sound-srate*
    (if (> g0 g1)                         ; g0 = g1 does not occur here.
        (pwlv 1 1 0)                      ; fade out
        (pwlv 0 1 1))))                   ; else fade in

;;; raised cosine fades
(defun raised-cos (g0 g1 curve)
  (setq curve
    (if (> curve 0)
        (exp-scale-mid (* 2 curve))       ; mid-point -3dB @ Adjust = 50%
        (exp-scale-mid (* 1.63 curve))))  ; mid-point -12dB @ Adjust = -50%
  (setf env
    (control-srate-abs *sound-srate*      ; sound srate required for accuracy.
      (cond
        ((= g0 g1) g0)                    ; amplify
        ((> g0 g1)                        ; fade down
          (snd-exp 
            (mult (pwlv (- 1 curve) 1 1)
              (snd-log (raised-cosin 90)))))
        (t (snd-exp                       ; fade up
             (mult (pwlv 1 1 (- 1 curve))
               (snd-log (raised-cosin -90))))))))
  (sum (min g0 g1)
    (mult (abs (- g0 g1)) env)))

;;; raised cosine curve
(defun raised-cosin (phase)
  (let ((hz (hz-to-step (/ (get-duration 2)))))
    (mult 0.5 
      (sum 1 
        (osc hz 1 *sine-table* phase)))))

;;; log or exponential curve scaled 0 to 1
;;; x is the minimum level in dB before scaling
(defun log-exp-curve (x direction)
  (control-srate-abs *sound-srate*
    (let ((x (db-to-linear x)))
      ;; If direction=0 fade-in else fade-out
      (if (= direction 0)
        (setf env (pwev x 1 1))
        (setf env (pwev 1 1 x)))      
      (mult (/ (- 1 x))                   ; normalize to 0 dB
        (diff env x)))))                  ; drop down to silence

;;; curve scaling for S-curve
(defun exp-scale-mid (x)
  (let ((e (exp 1.0)))
    (/ (- (exp (- 1 x)) e)
      (- 1 e))))

(let ((gain0 (string-to-val gain-string-0))
      (gain1 (string-to-val gain-string-1)))
  (if (and gain0 gain1)
    (check-values gain0 gain1)
    (setf err (format nil "~a" (invalid-string gain0 gain1))))
  (if (= (length err) 0)
      (fade *track* type curve gain0 gain1)
      (format nil "Error.~%~a." err)))