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			65 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			Common Lisp
		
	
	
	
	
	
			
		
		
	
	
			65 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			Common Lisp
		
	
	
	
	
	
;nyquist plug-in
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;version 4
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;type process spectral
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;preview linear
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;name "Spectral edit parametric EQ..."
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;action "Filtering..."
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;author "Paul Licameli"
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;copyright "Released under terms of the GNU General Public License version 2"
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;; SpectralEditParametricEQ.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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;control control-gain "Gain (dB)" real "" 0 -24 24
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(defun wet (sig gain fc bw)
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  (eq-band sig fc gain (/ bw 2)))
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(defun result (sig)
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  (let*
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      ((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 (format nil "~aPlease select frequencies." p-err)))
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      ((not f0)
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          (throw 'error-message (format nil "~aLow frequency is undefined." p-err)))
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      ((not f1)
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          (throw 'error-message (format nil "~aHigh frequency is undefined." p-err)))
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      ((and fc (= fc 0))
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          (throw 'error-message (format nil "~aCenter frequency must be above 0 Hz." p-err)))
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      ((and f1 (> f1 (/ *sound-srate* 2)))
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          (throw 'error-message
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            (format nil "~aFrequency selection is too high for track sample rate.
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                        For the current track, the high frequency setting cannot~%~
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                        be greater than ~a Hz"
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                    p-err (/ *sound-srate* 2))))
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      ((and bw (= bw 0))
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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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      ;; If centre frequency band is above Nyquist, do nothing.
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      ((and fc (>= fc (/ *sound-srate* 2.0)))
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          nil)
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      (t  (sum (prod env (wet sig control-gain fc bw))
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               (prod (diff 1.0 env) sig))))))
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(catch 'error-message
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  (setf p-err "Error.\n")
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  (if (= control-gain 0)
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      nil ; Do nothing
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      (multichan-expand #'result *track*)))
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