mirror of
https://github.com/cookiengineer/audacity
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108 lines
3.9 KiB
Common Lisp
108 lines
3.9 KiB
Common Lisp
$nyquist plug-in
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$version 4
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$type tool generate
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$name (_ "Sample Data Import")
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$manpage "Sample_Data_Import"
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$action (_ "Reading and rendering samples...")
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$author (_ "Steve Daulton")
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$release 2.3.0
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$copyright (_ "Released under terms of the GNU General Public License version 2")
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$control filename (_ "Select file") file "" "*default*/sample-data.txt" "Text file|*.txt;*.TXT|All files|*.*;*" "open,exists"
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$control bad-data (_ "Invalid data handling") choice (("ThrowError" (_ "Throw Error"))
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("ReadAsZero" (_ "Read as Zero"))) 0
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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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;; Check file can be opened
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(defun fileopensp (fname)
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(cond
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((not (setf fstream (open fname)))
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(throw 'err (format nil (_ "Error~%~
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'~a' could not be opened.~%~
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Check that file exists.")
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fname)))
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; File opened OK, so check for normal ASCII, then close it and return 'true'
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(t (do ((j 0 (1+ j))(b (read-byte fstream)(read-byte fstream)))
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((or (> j 100000)(not b)))
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(when (> b 127)
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(throw 'err (format nil (_ "Error:~%~
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The file must contain only plain ASCII text.~%~
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(Invalid byte '~a' at byte number: ~a)") b (1+ j) ))))
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(close fstream)
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t)))
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;; ':new' creates a new class 'streamreader'
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;; 'filestream' and 'chanel' are its instance variables.
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;; (every object of class 'streamreader' has its own
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;; copy of these variables)
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(setq streamreader
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(send class :new '(filestream chanel)))
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;; Initialize class 'streamreader'
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(send streamreader :answer :isnew '(stream ch) '(
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(setq filestream stream)
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(setq channel ch)))
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;; Create ':next' method.
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;; Snd-fromobject calls this method to obtain the
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;; next sound sample until it receives 'nil'
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(send streamreader :answer :next '() '(
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(case channel
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(0 ;mono
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(read-and-verify filestream))
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(1 ;left channel
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;Note, we still need to verify data even if skipping it.
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(let ((val (read-and-verify filestream)))
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(read-and-verify filestream) ;skip right channel sample
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val))
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(t ;right channel
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(read-and-verify filestream) ;skip left channel sample
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(read-and-verify filestream)))))
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(defun read-and-verify (stream)
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"snd-fromobject requires float values, nil to terminate"
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(let ((val (read stream)))
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(cond
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((not val) nil) ;end of file
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((numberp val) (float val)) ;valid.
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((= bad-data 0) ;invalid. Throw error and quit
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(throw 'err (format nil (_ "Error~%~
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Data must be numbers in plain ASCII text.~%~
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'~a' is not a numeric value.") val)))
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(t 0.0)))) ;invalid. Replace with zero.
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;; Instantiate a new sound object
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(defun make-sound-object (stream chan)
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(send streamreader :new stream chan))
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(defun sound-from-file (filename)
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;; Set path. fileopenp should return 'true'
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(if (not (fileopensp filename))
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(throw 'err (format nil (_ "Error.~%Unable to open file"))))
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; Note: we can't use (arrayp *track*) because
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; *track* is nil in generate type plug-ins.
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(cond
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((= (get '*track* 'channels) 2)
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(let ((left-snd (get-sound filename 1))
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(right-snd (get-sound filename 2)))
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(vector left-snd right-snd)))
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(t ;; Mono track
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(get-sound filename 0))))
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(defun get-sound (fname chan)
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(let* ((stream (open fname :direction :input))
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(left (make-sound-object stream chan)))
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(setf audio-out (snd-fromobject 0 *sound-srate* left))
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(snd-play audio-out) ;force samples to be calculated now.
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(close stream)
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audio-out))
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(catch 'err (sound-from-file filename))
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