lfo

lfo — A low frequency oscillator of various shapes.

Description

A low frequency oscillator of various shapes.

Syntax

kres lfo kamp, kcps [, itype]
ares lfo kamp, kcps [, itype]

Initialization

itype (optional, default=0) -- determine the waveform of the oscillator. Default is 0.

  • itype = 0 - sine

  • itype = 1 - triangles

  • itype = 2 - square (bipolar)

  • itype = 3 - square (unipolar)

  • itype = 4 - saw-tooth

  • itype = 5 - saw-tooth(down)

The sine wave is implemented as a 4096 table and linear interpolation. The others are calculated.

Performance

kamp -- amplitude of output

kcps -- frequency of oscillator

Examples

Here is an example of the lfo opcode. It uses the file lfo.csd.

Example 403. Example of the lfo opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
-odac      ;;;realtime audio out
;-iadc    ;;;uncomment -iadc if realtime audio input is needed too
; For Non-realtime ouput leave only the line below:
; -o lfo.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

sr = 44100
ksmps = 32
nchnls = 2
0dbfs  = 1

instr 1

kcps  = 5
itype = p4	;lfo type

klfo line 0, p3, 20
al   lfo klfo, kcps, itype
asig poscil .5, 220+al, 1
     outs asig, asig

endin
</CsInstruments>
<CsScore>
; sine wave.
f 1 0 32768 10 1

i 1 0 3 0	;lfo = sine
i 1 + 3 2	;lfo = square
i 1 + 3 5	;lfo = saw-tooth down
e
</CsScore>
</CsoundSynthesizer>


Credits

Author: John ffitch
University of Bath/Codemist Ltd.
Bath, UK
November 1998

New in Csound version 3.491