LIMITER
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LIMITER - amplitude limiter (non-linear)
The LIMITER
spatom applies a non-linear magnitude weighting to the signal. The limiter function is only applied if the absolute value of the signal magnitude is higher than the specified limiter start magnitude LIM. For the limiter function, the following algorithm is used:
with:
x, y | input and output signal sample |
LIM, MAX | limiter start amplitude and maximum signal amplitude |
f() | limiter function selected by input TYPE |
Table: Limiter functions{| |- |The value of TYPE |The limiter function f(z) |- |0 or RECTANGLE |File:1241.png ('cut-off') |- |1 or ATAN |File:1242.png |- |2 or EXPONENTIAL |File:1243.png |}
with:
The output Q is set to the relative number of processed samples:
Q = number of changed samples / number of processed samples
Usage:
LIMITER X TYPE MAX LIM
Inputs:
- X
- The signal vector or sample.
- TYPE
- The type of limiter function (see table above).
- MAX
- The maximum magnitude (full attenuation).
- LIM
- The limiter start magnitude. This value must be less than MAX.
Outputs:
- Y
- The limited signal (the same type as X).
- Q
- The relative number of limited (changed) samples.