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				synced 2025-11-04 08:04:06 +01:00 
			
		
		
		
	For shipped plug-ins, the version number is the same as the Audacity release version when the plug-in was last modified.
		
			
				
	
	
		
			39 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Common Lisp
		
	
	
	
	
	
			
		
		
	
	
			39 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Common Lisp
		
	
	
	
	
	
$nyquist plug-in
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$version 4
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$type process
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$preview linear
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$name (_ "Low-Pass Filter")
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$manpage "Low-Pass_Filter"
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$debugbutton disabled
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$action (_ "Performing Low-Pass Filter...")
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$author (_ "Dominic Mazzoni")
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$release 2.3.0
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$copyright (_ "Released under terms of the GNU General Public License version 2")
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;; Released under terms of the GNU General Public License version 2:
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;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
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;;
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;; For information about writing and modifying Nyquist plug-ins:
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;; https://wiki.audacityteam.org/wiki/Nyquist_Plug-ins_Reference
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$control frequency (_ "Frequency (Hz)") float-text "" 1000 0 nil
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$control rolloff (_ "Roll-off (dB per octave)") choice (("dB6" (_ "6 dB"))
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                                                        ("dB12" (_ "12 dB"))
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                                                        ("dB24" (_ "24 dB"))
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                                                        ("dB36" (_ "36 dB"))
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                                                        ("dB48" (_ "48 dB"))) 0
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(cond
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  ((< frequency 0.1) (_ "Frequency must be at least 0.1 Hz."))
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  ((>= frequency (/ *sound-srate* 2.0))
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      (format nil (_ "Error:~%~%Frequency (~a Hz) is too high for track sample rate.~%~%~
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                   Track sample rate is ~a Hz~%~
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                   Frequency must be less than ~a Hz.")
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              frequency
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              *sound-srate*
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              (/ *sound-srate* 2.0)))
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  (T  (funcall (nth rolloff '(lp lowpass2 lowpass4 lowpass6 lowpass8))
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               *track* frequency)))
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