45 lines
1.3 KiB
Common Lisp
45 lines
1.3 KiB
Common Lisp
$nyquist plug-in
|
|
$version 4
|
|
$type analyze
|
|
$name (_ "Beat Finder")
|
|
$manpage "Beat_Finder"
|
|
$action (_ "Finding beats...")
|
|
$author (_ "Audacity")
|
|
$release 2.3.2
|
|
$copyright (_ "Released under terms of the GNU General Public License version 2")
|
|
|
|
;; 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:
|
|
;; https://wiki.audacityteam.org/wiki/Nyquist_Plug-ins_Reference
|
|
|
|
|
|
$control thresval (_ "Threshold Percentage") int "" 65 5 100
|
|
|
|
(setf threshold (/ thresval 100.0))
|
|
|
|
(defun mix-to-mono (sig)
|
|
(if (arrayp sig)
|
|
(sum (aref sig 0) (aref sig 1))
|
|
sig))
|
|
|
|
(defun bass-tracker (sig)
|
|
(let* ((bass (lp sig 50))
|
|
;(snd-follow sound floor risetime falltime lookahead)
|
|
(follower (snd-follow bass 0.001 0.01 0.1 512)))
|
|
(force-srate 1000 (lp follower 10))))
|
|
|
|
|
|
(let ((beats (bass-tracker (mix-to-mono *track*))))
|
|
(setf peak-sig (peak beats ny:all))
|
|
(setf threshold (* threshold peak-sig))
|
|
(do ((time 0.0 (+ time 0.001))
|
|
(val (snd-fetch beats) (snd-fetch beats))
|
|
(flag T)
|
|
labels)
|
|
((not val) labels)
|
|
(when (and flag (> val threshold))
|
|
(push (list time "B") labels))
|
|
(setf flag (< val threshold))))
|