clip
clip — Clips a signal to a predefined limit.
Description
Clips an a-rate signal to a predefined limit, in a “soft” manner, using one of three methods.
Initialization
imeth -- selects the clipping method. The default is 0. The methods are:
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0 = Bram de Jong method (default)
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1 = sine clipping
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2 = tanh clipping
ilimit -- limiting value
iarg (optional, default=0.5) -- when imeth = 0, indicates the point at which clipping starts, in the range 0 - 1. Not used when imeth = 1 or imeth = 2. Default is 0.5.
Performance
asig -- a-rate input signal
The Bram de Jong method (imeth = 0) applies the algorithm (denoting ilimit as limit and iarg as a):
|x| >= 0 and |x| <= (limit*a): f(x) = f(x) |x| > (limit*a) and |x| <= limit: f(x) = sign(x) * (limit*a+(x-limit*a)/(1+((x-limit*a)/(limit*(1-a)))2)) |x| > limit: f(x) = sign(x) * (limit*(1+a))/2
The second method (imeth = 1) is the sine clip:
|x| < limit: f(x) = limit * sin(π*x/(2*limit)), |x| >= limit: f(x) = limit * sign(x)
The third method (imeth = 2) is the tanh clip:
|x| < limit: f(x) = limit * tanh(x/limit)/tanh(1), |x| >= limit: f(x) = limit * sign(x)
![[Note]](images/note.png)
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Note |
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Method 1 appears to be non-functional at release of Csound version 4.07. |
Examples
Here is an example of the clip opcode. It uses the file clip.csd.
Example 146. Example of the clip 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 ;;;RT audio out ;-iadc ;;;uncomment -iadc if RT audio input is needed too ; For Non-realtime ouput leave only the line below: ; -o clip.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 instr 1 ; white noise arnd rand 1 ; full amlitude ; Clip the noisy waveform's amplitude to 0.5 a1 clip arnd, p4, 0.5 outs a1, a1 endin instr 2 ; white noise arnd rand 1 ; full amlitude ; Clip the noisy waveform's amplitude to 0.1 a1 clip arnd, p4, 0.1 outs a1, a1 endin </CsInstruments> <CsScore> ; Play Instrument #1 for one second. i 1 0 1 2 ; Play Instrument #2 for one second. i 2 1 1 2 s 3 ; Play Instrument #1 for one second. i 1 0 1 0 ; Play Instrument #2 for one second. i 2 1 1 0 s 3 ; Play Instrument #1 for one second. i 1 0 1 1 ; Play Instrument #2 for one second. i 2 1 1 1 e </CsScore> </CsoundSynthesizer>