linked-named-object/sndfile [ Classes ]
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NAME
sndfile File: sndfile.lsp Class Hierarchy: named-object -> linked-named-object -> sndfile Version: 1.0.12 Project: slippery chicken (algorithmic composition) Purpose: Implementation of the sndfile class that holds information about a sound file as well as specifying desired parameters Author: Michael Edwards: m@michael-edwards.org Creation date: March 21st 2001 $$ Last modified: 16:21:09 Fri Mar 3 2023 CET SVN ID: $Id$
sndfile/centroid [ Methods ]
[ Top ] [ sndfile ] [ Methods ]
DATE
February 7th 2023, Heidhausen
DESCRIPTION
Calculate the average spectral centroid of a sound file, between the start and end points given. This requires CLM's scentroid.ins to be compiled and loaded in advance. Note that the averaging is done by FFT analysis every 10 milliseconds and with an FFT size of 4096 samples. FFT frames that have an RMS amplitude of < -40dbFS will be ignored.
ARGUMENTS
the sndfile object
RETURN VALUE
The frequency of the centroid in Hertz.
SYNOPSIS
(defmethod centroid ((sf sndfile))
sndfile/make-sndfile [ Functions ]
[ Top ] [ sndfile ] [ Functions ]
DESCRIPTION
Create a sndfile object to hold data about an existing sound file, specifying at least the path and file name of that sound file. Optional arguments allow for the specification of segments within the given sound file and its perceived fundamental frequency (for src-based transposition). If the first argument ("path") is a list, then this sndfile object has been created from within a sndfile-palette object. In this case, the first item in the list will be the full path to the sound file, as defined in the sndfile-palette object; the second item in the list is the list given by the user containing the data slots to be used, whereby the first item of that list must be the ID of the object. NB: This function creates an object of the class sndfile, which is contains data concerning an existing sound file. It does not create an actual sound file.
ARGUMENTS
- A path and file name of an existing sound file; or a list as explained above.
OPTIONAL ARGUMENTS
keyword arguments: - :id. An ID for the sndfile. Will be set automatically if created from within a sndfile-palette. Default nil. - :data. The given file name, including path and extension, usually set automatically to be the given path if nil. Default nil. - :duration. A number in seconds which is the duration of the segment of the specified sound file which the user would like to use. This should not be specified if :end has been specified. Default nil. - :end. A number in seconds which is the end time within the source sound file for the segment of the file which the user would like to use. This should not be specified if :duration has been specified. Default nil. - :start. A number in seconds which is the start time within the source sound file for the segment of the file which the user would like to use. Defaults to 0.0. - :frequency. A number or note-name symbol. This frequency will serve as the reference pitch for any src transpositions of this file. This can be any value, but will most likely be specified if the source sound file has a perceptible fundamental pitch. If given as a number, this number will be handled as a frequency in Hertz. Default = 'C4. - :amplitude. An number that is the amplitude which the user would like to designate for this sound file. This number may be of any value, as slippery chicken normalizes all sound file events; however, standard practice would suggest that this should fall between 0.0 and 1.0. Default = 1.0
RETURN VALUE
A sndfile object.
EXAMPLE
;; Example specifying the full path, a start and end time, and a base frequency (make-sndfile "/path/to/sndfile-1.aiff" :start 0.3 :end 1.1 :frequency 654) => SNDFILE: path: /path/to/sndfile-1.aiff, snd-duration: 3.011043, channels: 1, frequency: 654 start: 0.3, end: 1.1, amplitude: 1.0, duration 0.8 will-be-used: 0, has-been-used: 0 data-consistent: T LINKED-NAMED-OBJECT: previous: NIL, this: NIL, next: NIL NAMED-OBJECT: id: NIL, tag: NIL, data: /path/to/sndfile-1.aiff ;; Example using the sndfile-palette list as the first argument (make-sndfile '("/path/to/sndfile-1.aiff" (nil :start 0.3 :end 1.1))) => SNDFILE: path: /path/to/sndfile-1.aiff, snd-duration: 3.011043, channels: 1, frequency: 261.62555 start: 0.3, end: 1.1, amplitude: 1.0, duration 0.8 will-be-used: 0, has-been-used: 0 data-consistent: T LINKED-NAMED-OBJECT: previous: NIL, this: NIL, next: NIL NAMED-OBJECT: id: "/Volumes/JIMMY/SlipperyChicken/sndfile-2.aiff", tag: NIL, data: /path/to/sndfile-1.aiff
SYNOPSIS
(defun make-sndfile (path &key id data duration end (start 0.0)
(frequency nil)
(amplitude 1.0))
sndfile/reset-usage [ Methods ]
[ Top ] [ sndfile ] [ Methods ]
DESCRIPTION
Reset the WILL-BE-USED and HAS-BEEN-USED slots of the given sndfile object to 0. These slots keep track of how many times a sound will be used and has been used, which is useful for purposes such as incrementing start-time. These slots are set internally and are not intended to be set by the user.
ARGUMENTS
- A sndfile object.
RETURN VALUE
Returns 0.
EXAMPLE
;; First set the values of the WILL-BE-USED and HAS-BEEN-USED slots, as these ;; are 0 when a new sndfile object is created using make-sndfile. Set the ;; values, print them; reset both using reset-usage, and print again to see ;; the change. (let ((sf-1 (make-sndfile "/path/to/sndfile-1.aiff")))) (setf (will-be-used sf-1) 11) (setf (has-been-used sf-1) 13) (print (will-be-used sf-1)) (print (has-been-used sf-1)) (reset-usage sf-1) (print (will-be-used sf-1)) (print (has-been-used sf-1))) => 11 13 0 0
SYNOPSIS
(defmethod reset-usage ((sf sndfile))
sndfile/stereo [ Methods ]
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DESCRIPTION
Test whether the CHANNELS slot of a given sndfile object is set to 2.
ARGUMENTS
- A sndfile object.
RETURN VALUE
Returns T if the CHANNELS slot is set to 2, otherwise returns NIL.
EXAMPLE
;; The method make-sndfile creates a sndfile object with the CHANNELS slot set ;; to NIL. Make a sndfile object, test to see whether the value of the CHANNELS ;; slot is 2; set the CHANNELS slot to 2 and test again. (let ((sf-1 (make-sndfile "/path/to/sndfile-1.aiff"))) (print (stereo sf-1)) (setf (channels sf-1) 2) (print (stereo sf-1))) => NIL T
SYNOPSIS
(defmethod stereo ((sf sndfile))