rsc3/doc/examples/ugen/delays/play-buf.help.scm

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Scheme

;; (play-buf numChannels bufnum rate trigger startPos loop)
;; Sample playback oscillator. Plays back a memory resident sample.
;; numChannels - number of channels that the buffer will be. This
;; must be a fixed integer. The architechture of the
;; SynthDef cannot change after it is compiled.
;; Warning: if you supply a bufnum of a buffer that has
;; a different numChannels then you have specified to
;; the play-buf, it will fail silently.
;; bufnum - the index of the buffer to use
;; rate - 1.0 is the server's sample rate, 2.0 is one octave up, 0.5
;; is one octave down -1.0 is backwards normal rate
;; etc. interpolation is cubic. Note: If the buffer's sample
;; rate is different from the server's, you will need to
;; multiply the desired playback rate by (file's rate /
;; server's rate). The UGen buf-rate-scale.kr(bufnum) returns
;; this factor. See examples below. buf-rate-scale should be used
;; in virtually every case.
;; trigger - a trigger causes a jump to the startPos. A trigger
;; occurs when a signal changes from <= 0 to > 0.
;; startPos - sample frame to start playback.
;; loop - 1 means true, 0 means false. This is modulate-able.
(with-sc3
(lambda (fd)
(async fd (b-alloc-read 10 "/home/rohan/audio/metal.wav" 0 0))))
;; Play once only.
(audition (out 0 (play-buf 1 10 (buf-rate-scale kr 10) 1 0 0)))
;; Play in infinite loop.
(audition (out 0 (play-buf 1 10 (buf-rate-scale kr 10) 1 0 1)))
;; trigger playback at each pulse.
(audition (out 0 (play-buf 1 10 (buf-rate-scale kr 10) (impulse kr 2 0) 0 0)))
;; trigger playback at each pulse (diminishing intervals).
(let ((t (impulse kr (x-line kr 0.1 100 10 remove-synth) 0)))
(audition (out 0 (play-buf 1 10 (buf-rate-scale kr 10) t 0 0))))
;; Loop playback, accelerating pitch.
(let ((rate (x-line kr 0.1 100 60 remove-synth)))
(audition (out 0 (play-buf 1 10 rate 1 0 1))))
;; Sine wave control of playback rate, negative rate plays backwards.
(let ((r (mul-add (f-sin-osc kr (x-line kr 0.2 8 30 remove-synth) 0) 3 0.6)))
(audition (out 0 (play-buf 1 10 (mul (buf-rate-scale kr 10) r) 1 0 1))))
;; Release buffer.
(with-sc3
(lambda (fd)
(async fd (b-free 10))))