PartConv

A UGen for partitioned convolution. Its advantage over non-partitioning UGens such as Convolution2 is that the impulse response can be arbitrarily large amortization is used to spread processing and avoid CPU spikes.

The impulse response buffer must be specially prepared, using a /b_gen command that transforms an existing regularly formatted buffer to a new partitioned convolution ready buffer.

Examples

// Dan Stowell's reverb
// synthesize impulse response
val ir = (1f +: Vector.fill(100)(0f)) ++ (1f to 0f by -0.00002f).map { f =>
  if (math.random < 0.5)
    0f
  else
    f.pow(8) * (math.random - 0.5).signum * 0.1f
}

// ir.plot()

// send the IR to a regular buffer
val irBuf = Buffer(s)
irBuf.alloc(ir.size)
irBuf.setData(ir)

// calculate the partitioning parameters
val fftSize  = 2048
val numPart  = (ir.size * 2.0 / fftSize).ceil.toInt  // 49
val partSize = fftSize * numPart  // 100352

// create the specially formatted partitioned buffer
val partBuf  = Buffer(s)
partBuf.alloc(partSize)
// currently no predefined method for this command!
s ! osc.Message("/b_gen", partBuf.id, "PreparePartConv", irBuf.id, fftSize)

// now we can forget about the input buffer
irBuf.free()

val x = play {
  // trigger IR every 4 seconds
  val in = Impulse.ar(0.25) * 0.5
  PartConv.ar(in, fftSize, partBuf.id)
}

// do not forget to free the buffer eventually
x.free(); partBuf.free()

See also: Convolution2
Convolution

Linear Supertypes

Serializable, Serializable, AnyRef, Any

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def ar(in: GE, fftSize: GE, buf: GE): PartConv

in
the realtime input to be convolved
fftSize
FFT size which is twice the input signal partition size. This must be a multiple of the control-block size, and there must be at least two blocks per partition (to allow for amortization) (init-time only)
buf
buffer identifier for the fixed kernel (init-time only). (init-time only)
final def asInstanceOf[T0]: T0

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def clone(): AnyRef

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protected[java.lang]
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@throws( ... )
final def eq(arg0: AnyRef): Boolean

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def equals(arg0: Any): Boolean

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def finalize(): Unit

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protected[java.lang]
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@throws( classOf[java.lang.Throwable] )
final def getClass(): Class[_]

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def hashCode(): Int

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final def isInstanceOf[T0]: Boolean

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final def ne(arg0: AnyRef): Boolean

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final def notify(): Unit

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final def notifyAll(): Unit

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final def synchronized[T0](arg0: ⇒ T0): T0

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def toString(): String

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final def wait(): Unit

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Related Docs: class PartConv | package ugen

object PartConv extends Serializable

Examples

Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

def ar(in: GE, fftSize: GE, buf: GE): PartConv

final def asInstanceOf[T0]: T0

def clone(): AnyRef

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

final def getClass(): Class[_]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Inherited from Serializable

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

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