Packages

object Convolution2 extends ProductReader[Convolution2] with Serializable

A frequency-domain convolution UGen using a fixed kernel which can be updated by a trigger signal. The delay caused by the convolution when the kernel is a dirac impulse is equal to frameSize - controlBlockSize , so for a frameSize of 2048 and a control-block size of 64, this is 1984 sample frames.

Examples
// three example kernels
// creates a buffer with `n` set values
def mkBuf(n: Int, amp: => Double): Buffer = {
  val v = Vector.tabulate[FillValue](n) { i =>
    (i.linLin(0, n, 0, 2048).toInt, amp)
  }
  val b = Buffer(s)
  b.alloc(2048, completion = b.zeroMsg(b.setMsg(v: _*)))
  b
}

val b = mkBuf(3, 1)
val c = mkBuf(50, math.random)
val d = mkBuf(20, 1)

val x = play {
  val z   = Impulse.ar(1)
  val buf = "kernel".kr(b.id)
  val tr  = "trig"  .tr
  Convolution2.ar(z, buf, tr, 2048) * 0.5
}

// set buffer and trigger kernel actualization
x.set("kernel" -> b.id, "trig" -> 1)
x.set("kernel" -> c.id, "trig" -> 1)
x.set("kernel" -> d.id, "trig" -> 1)

x.free(); b.free(); c.free(); d.free()
See also

PartConv

Convolution2L

Convolution

Linear Supertypes
Serializable, ProductReader[Convolution2], AnyRef, Any
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Inherited
  1. Convolution2
  2. Serializable
  3. ProductReader
  4. AnyRef
  5. Any
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Value Members

  1. def ar(in: GE, kernel: GE, trig: GE = 1, frameSize: GE): Convolution2

    in

    the realtime input to be convolved

    kernel

    buffer identifier for the fixed kernel, which may be modulated in combination with the trigger. Even a trigger input of zero is used, upon UGen initialization the kernel must point to a valid buffer, otherwise the UGen aborts.

    trig

    updates the kernel on a change from non-positive to positive (<= 0 to >0)

    frameSize

    size of the kernel. this must be a power of two. the FFT calculated internally by the UGen has a size of twice this value. The maximum allowed frameSize is 16384. (init-time only)

  2. def read(in: RefMapIn, key: String, arity: Int): Convolution2
    Definition Classes
    Convolution2 → ProductReader