SincFilter_FSc.scala

val sr        = "sample-rate".attr(44100.0)
//val noiseLen  = "noise-dur".attr(1.0).max(0.0) * sr
val numZero   = "zero-crossings".attr(6).max(1)
val f1        = "f1".attr( 500.0)
val f2        = "f2".attr(1000.0)
//val roll      = "roll".attr(0.0)
val tpe       = "type".attr(1).clip(0, 4)

//val noise     = WhiteNoise().take(noiseLen)
val noiseLen  = 1
val noise     = DC(1.0).take(1)

val f1N       = f1 / sr
val f2N       = f2 / sr
val fltLenH   = (numZero / f1N).ceil.max(1)
val fltLen    = fltLenH * 2 // - 1

val convLen   = noiseLen + fltLen - 1
val fftLen    = convLen.nextPowerOfTwo
val noiseF    = Real1FFT(noise, noiseLen, fftLen - noiseLen, mode = 1)

val flt0: GE = If (tpe sig_== 0) Then {
  // all-pass
  ResizeWindow(DC(1.0).take(1), 1, start = -fltLenH, stop = fltLenH - 1)
} ElseIf (tpe sig_== 1) Then {
  // low-pass
  GenWindow(fltLen, shape = GenWindow.Sinc, param = f1N) * f1N
} ElseIf (tpe sig_== 2) Then {
  // high-pass
  GenWindow(fltLen, shape = GenWindow.Sinc, param = 0.5) * 0.5 -
  GenWindow(fltLen, shape = GenWindow.Sinc, param = f1N) * f1N
} ElseIf (tpe sig_== 3) Then {
  // band-pass
  GenWindow(fltLen, shape = GenWindow.Sinc, param = f2N) * f2N -
  GenWindow(fltLen, shape = GenWindow.Sinc, param = f1N) * f1N
} Else {
  // band-stop
  GenWindow(fltLen, shape = GenWindow.Sinc, param = 0.5) * 0.5 -
  GenWindow(fltLen, shape = GenWindow.Sinc, param = f2N) * f2N +
  GenWindow(fltLen, shape = GenWindow.Sinc, param = f1N) * f1N
}
val win = GenWindow(fltLen, shape = GenWindow.Kaiser, param = 6.0)
val flt = (flt0 * win).take(fltLen)
//Plot1D(flt, fltLen)

val fltF      = Real1FFT(flt, fltLen, fftLen - fltLen, mode = 1)
val convF     = noiseF.complex * fltF
val conv      = Real1IFFT(convF, fftLen, mode = 1)
val sig       = conv.take(convLen)

AudioFileOut("out", sig, sampleRate = sr)