22 lines
982 B
EmacsLisp
22 lines
982 B
EmacsLisp
(defun play-scale (freq-list dur)
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"Play a list of frequencies."
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(setq header (unibyte-string ; AU header:
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46 115 110 100 ; ".snd" magic number
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0 0 0 24 ; start of data bytes
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255 255 255 255 ; file size is unknown
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0 0 0 3 ; 16 bit PCM samples
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0 0 172 68 ; 44,100 samples/s
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0 0 0 1)) ; mono
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(setq s nil)
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(dolist (freq freq-list)
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(setq v (mapcar (lambda (x)
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(mod (round (* 32000 (sin (* 2 pi freq x (/ 44100.0))))) 65536))
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(number-sequence 0 (* dur 44100))))
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(setq s (apply #'concat s (flatten-list (mapcar (lambda (x)
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(list (unibyte-string (ash x -8))
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(unibyte-string (mod x 256))))
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v)))))
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(setq s (concat header s))
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(play-sound `(sound :data ,s)))
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(play-scale '(261.63 293.66 329.63 349.23 392.00 440.00 493.88 523.25) .5)
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