simplelp - Low pass filter using simple and fast diff equation.
Inputs:
in [BUFFER] [REQUIRED]: input buffer to be filtered.
cutoff [BUFFER|FLOAT] [REQUIRED]: frequency cutoff.
Outputs:
out [BUFFER]: output, filtered buffer.
Applies the following differential equation:
Y[n] = (1. - u) * Y[n - 1] + u * X[n]
Where:
u = cutoff / samplingRate