Steve Daulton's contributions

plug-ins/StudioFadeOut.ny

@@ -0,0 +1,43 @@
+;nyquist plug-in
+;version 1
+;type process
+;categories "http://lv2plug.in/ns/lv2core#MixerPlugin"
+;name "Studio Fade Out"
+;action "Applying Fade..."
+;info "by Steve Daulton. (www.easyspacepro.com).\nReleased under GPL v2.\n"
+
+;; StudioFadeOut.ny by Steve Daulton December 2012.
+;; Released under terms of the GNU General Public License version 2:
+;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+;;
+;; Produce a smooth and musical sounding fade out.
+;; Applies a sinusoidal fade out with a progressive low-pass
+;; filter from full spectrum at start to 100 Hz at end.
+;;
+;; For information about writing and modifying Nyquist plug-ins:
+;; http://wiki.audacityteam.org/wiki/Nyquist_Plug-ins_Reference
+
+;;; sweeping low pass filter 
+ (defun filter (sig dur)
+  (abs-env
+    ;; cross-fade the filter
+    (let* ((nyq-hz (/ *sound-srate* 2))
+           (f-out (r-cos (min (/ dur 2.0) 0.5)))
+           (f-in (diff (snd-const 1 0 *sound-srate* dur) f-out)))
+      (sim
+        (mult f-out sig)
+        (mult f-in (lp sig (pwlv nyq-hz dur 100)))))))
+
+;;; raised cosine
+(defun r-cos (dur)
+  (abs-env
+    (mult 0.5 
+      (sum 1 
+        (osc (hz-to-step (/ (* dur 2))) dur *table* 90)))))
+
+(let ((dur (get-duration 1)))
+  (cond
+    ((< len 3) "Selection too short.\nIt must be more than 2 samples.")
+    ((< dur 0.2) (mult s (r-cos dur)))
+    (t (mult (filter s dur)(r-cos dur)))))
+