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72 lines
2.8 KiB
Common Lisp
72 lines
2.8 KiB
Common Lisp
$nyquist plug-in
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$version 4
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$type process spectral
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$name (_ "Spectral edit multi tool")
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$manpage "Spectral_edit_multi_tool"
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$action (_ "Filtering...")
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$author (_ "Paul Licameli")
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$release 2.3.0
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$copyright (_ "Released under terms of the GNU General Public License version 2")
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;; SpectralEditMulti.ny by Paul Licameli, November 2014.
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;; Updated by Steve Daulton 2014 / 2015.
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;; Released under terms of the GNU General Public License version 2:
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;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
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;;
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;; For information about writing and modifying Nyquist plug-ins:
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;; https://wiki.audacityteam.org/wiki/Nyquist_Plug-ins_Reference
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(defun wet (sig f0 f1 fc)
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(cond
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((not f0) (highpass2 sig f1))
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((not f1) (lowpass2 sig f0))
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(T (let ((q (/ fc (- f1 f0))))
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(notch2 sig fc q)))))
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(defun result (sig)
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(let* ((f0 (get '*selection* 'low-hz))
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(f1 (get '*selection* 'high-hz))
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(fc (get '*selection* 'center-hz))
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(bw (get '*selection* 'bandwidth))
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(tn (truncate len))
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(rate (snd-srate sig))
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(transition (truncate (* 0.01 rate))) ; 10 ms
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(t1 (min transition (/ tn 2))) ; fade in length (samples)
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(t2 (max (- tn transition) (/ tn 2))) ; length before fade out (samples)
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(breakpoints (list t1 1.0 t2 1.0 tn))
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(env (snd-pwl 0.0 rate breakpoints)))
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(cond
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((not (or f0 f1)) ; This should never happen for a 'spectral' effect.
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(throw 'error-message
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(format nil (_ "~aPlease select frequencies.") p-err)))
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((and f0 f1 (= f0 f1))
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(throw 'error-message
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(format nil (_ "~aBandwidth is zero (the upper and lower~%~
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frequencies are both ~a Hz).~%~
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Please select a frequency range.")
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p-err f0)))
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;; Biqud filter fails if centre frequency is very low and bandwidth very high.
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;; 'Magic numbers' 10 Hz and 10 octaves are experimental.
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((and f0 (< f0 10) (or (not bw)(> bw 10)))
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(throw 'error-message
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(format nil (_ "~aNotch filter parameters cannot be applied.~%~
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Try increasing the low frequency bound~%~
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or reduce the filter 'Width'.")
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p-err)))
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;; low pass frequency is above Nyquist so do nothing
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((and (not f1) (>= f0 (/ *sound-srate* 2.0)))
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nil)
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;; notch frequency is above Nyquist so do nothing
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((and f0 f1 (>= fc (/ *sound-srate* 2.0)))
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nil)
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;; high-pass above Nyquist so fade to silence
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((and (not f0) (>= f1 (/ *sound-srate* 2.0)))
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(mult sig (diff 1.0 env)))
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(T (sum (prod env (wet sig f0 f1 fc))
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(prod (diff 1.0 env) sig))))))
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(catch 'error-message
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(setf p-err (format nil (_ "Error.~%")))
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(multichan-expand #'result *track*))
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