distort1 — Modified hyperbolic tangent distortion.
Implementation of modified hyperbolic tangent distortion. distort1 can be used to generate wave shaping distortion based on a modification of the tanh function.
exp(asig * (shape1 + pregain)) - exp(asig * (shape2 - pregain))
aout = ---------------------------------------------------------------
exp(asig * pregain) + exp(-asig * pregain)
imode (Csound version 5.00 and later only; optional, defaults to 0) -- scales kpregain, kpostgain, kshape1, and kshape2 for use with audio signals in the range -32768 to 32768 (imode=0), -0dbfs to 0dbfs (imode=1), or disables scaling of kpregain and kpostgain and scales kshape1 by kpregain and kshape2 by -kpregain (imode=2).
asig -- is the input signal.
kpregain -- determines the amount of gain applied to the signal before waveshaping. A value of 1 gives slight distortion.
kpostgain -- determines the amount of gain applied to the signal after waveshaping.
kshape1 -- determines the shape of the positive part of the curve. A value of 0 gives a flat clip, small positive values give sloped shaping.
kshape2 -- determines the shape of the negative part of the curve.
Here is an example of the distort1 opcode. It uses the file distort1.csd.
Example 119. Example of the distort1 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 ; Audio out Audio in No messages -odac -iadc -d ;;;RT audio I/O ; For Non-realtime ouput leave only the line below: ; -o distort1.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; Initialize the global variables. sr = 44100 kr = 4410 ksmps = 10 nchnls = 2 gadist init 0 instr 1 iamp = p4 ifqc = cpspch(p5) asig pluck iamp, ifqc, ifqc, 0, 1 gadist = gadist + asig endin instr 50 kpre init p4 kpost init p5 kshap1 init p6 kshap2 init p7 aout distort1 gadist, kpre, kpost, kshap1, kshap2 outs aout, aout gadist = 0 endin </CsInstruments> <CsScore> ; Sta Dur Amp Pitch i1 0.0 3.0 10000 6.00 i1 0.5 2.5 10000 7.00 i1 1.0 2.0 10000 7.07 i1 1.5 1.5 10000 8.00 ; Sta Dur PreGain PostGain Shape1 Shape2 i50 0 3 2 1 0 0 e </CsScore> </CsoundSynthesizer>