Packages

final case class Onsets(chain: GE, thresh: GE = 0.5f, fun: GE = 3, decay: GE = 1.0f, noiseFloor: GE = 0.1f, minGap: GE = 10, medianSpan: GE = 11, whType: GE = 1, raw: GE = 0) extends SingleOut with ControlRated with IsIndividual with Product with Serializable

An onset detecting UGen for musical audio signals. It detects the beginning of notes/drumbeats/etc. Outputs a control-rate trigger signal which is 1 when an onset is detected, and 0 otherwise.

The onset detection should work well for a general range of monophonic and polyphonic audio signals. The onset detection is purely based on signal analysis and does not make use of any "top-down" inferences such as tempo.

There are different functions available for the analysis:

- 0 "power" -- generally OK, good for percussive input, and also very efficient - 1 "magsum" -- generally OK, good for percussive input, and also very efficient - 2 "complex" -- performs generally very well, but more CPU-intensive - 3 "rcomplex" (default) -- performs generally very well, and slightly more efficient than "complex" - 4 "phase" -- generally good, especially for tonal input, medium efficiency - 5 "wphase" -- generally very good, especially for tonal input, medium efficiency - 6 "mkl" -- generally very good, medium efficiency, pretty different from the other methods

The differences aren't large, so it is recommended you stick with the default "rcomplex" unless you find specific problems with it. Then maybe try "wphase". The "mkl" type is a bit different from the others so maybe try that too. They all have slightly different characteristics, and in tests perform at a similar quality level.

chain

the output (buffer) of an FFT UGen which transforms the audio input to track. For the FFT chain, you should typically use a frame size of 512 or 1024 (at 44.1 kHz sampling rate) and 50% hop size (which is the default setting in SC). For different sampling rates choose an FFT size to cover a similar time-span (around 10 to 20 ms).

thresh

the detection threshold, typically between 0 and 1, although in rare cases you may find values outside this range useful

fun

index of a function to be used to analyse the signal. See main paragraph for possible values (usually can be left to default).

decay

(advanced setting) Specifies the time (in seconds) for the normalisation to "forget" about a recent onset. If you find too much re-triggering (e.g. as a note dies away unevenly) then you might wish to increase this value. Not used with "mkl".

noiseFloor

(advanced setting) This is a lower limit, connected to the idea of how quiet the sound is expected to get without becoming indistinguishable from noise. For some cleanly-recorded classical music with wide dynamic variations, it was found helpful to go down as far as 1e-6. Not used with "mkl".

minGap

(advanced setting) Specifies a minimum gap (in FFT frames) between onset detections, a brute-force way to prevent too many doubled detections.

medianSpan

(advanced setting) Specifies the size (in FFT frames) of the median window used for smoothing the detection function before triggering.

whType

(advanced setting) ?

raw

(advanced setting) ? (init-time only)

See also

PV_JensenAndersen

PV_HainsworthFoote

Linear Supertypes
Serializable, Serializable, IsIndividual, ControlRated, SingleOut, SomeOut, GE.Lazy, GE, UGenSource[UGenInLike], Expander[UGenInLike], Lazy, Product, Equals, AnyRef, Any
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  1. Onsets
  2. Serializable
  3. Serializable
  4. IsIndividual
  5. ControlRated
  6. SingleOut
  7. SomeOut
  8. Lazy
  9. GE
  10. UGenSource
  11. Expander
  12. Lazy
  13. Product
  14. Equals
  15. AnyRef
  16. Any
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Instance Constructors

  1. new Onsets(chain: GE, thresh: GE = 0.5f, fun: GE = 3, decay: GE = 1.0f, noiseFloor: GE = 0.1f, minGap: GE = 10, medianSpan: GE = 11, whType: GE = 1, raw: GE = 0)

    chain

    the output (buffer) of an FFT UGen which transforms the audio input to track. For the FFT chain, you should typically use a frame size of 512 or 1024 (at 44.1 kHz sampling rate) and 50% hop size (which is the default setting in SC). For different sampling rates choose an FFT size to cover a similar time-span (around 10 to 20 ms).

    thresh

    the detection threshold, typically between 0 and 1, although in rare cases you may find values outside this range useful

    fun

    index of a function to be used to analyse the signal. See main paragraph for possible values (usually can be left to default).

    decay

    (advanced setting) Specifies the time (in seconds) for the normalisation to "forget" about a recent onset. If you find too much re-triggering (e.g. as a note dies away unevenly) then you might wish to increase this value. Not used with "mkl".

    noiseFloor

    (advanced setting) This is a lower limit, connected to the idea of how quiet the sound is expected to get without becoming indistinguishable from noise. For some cleanly-recorded classical music with wide dynamic variations, it was found helpful to go down as far as 1e-6. Not used with "mkl".

    minGap

    (advanced setting) Specifies a minimum gap (in FFT frames) between onset detections, a brute-force way to prevent too many doubled detections.

    medianSpan

    (advanced setting) Specifies the size (in FFT frames) of the median window used for smoothing the detection function before triggering.

    whType

    (advanced setting) ?

    raw

    (advanced setting) ? (init-time only)

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  5. val chain: GE
  6. def clone(): AnyRef
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @native() @throws( ... )
  7. val decay: GE
  8. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  9. def finalize(): Unit
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  10. val fun: GE
  11. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  12. lazy val hashCode: Int
    Definition Classes
    UGenSource → AnyRef → Any
  13. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  14. def makeUGen(_args: Vec[UGenIn]): UGenInLike
    Attributes
    protected
    Definition Classes
    OnsetsUGenSource
  15. def makeUGens: UGenInLike

    Abstract method which must be implemented by creating the actual UGens during expansion.

    Abstract method which must be implemented by creating the actual UGens during expansion. This method is at most called once during graph expansion

    returns

    the expanded object (depending on the type parameter U)

    Attributes
    protected
    Definition Classes
    OnsetsExpander
  16. val medianSpan: GE
  17. val minGap: GE
  18. final def name: String
    Definition Classes
    UGenSource
  19. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  20. val noiseFloor: GE
  21. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  22. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  23. final def rate: Rate
    Definition Classes
    ControlRated
  24. val raw: GE
  25. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  26. val thresh: GE
  27. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  28. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  29. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @throws( ... )
  30. val whType: GE

Inherited from Serializable

Inherited from Serializable

Inherited from IsIndividual

Inherited from ControlRated

Inherited from SingleOut

Inherited from SomeOut

Inherited from GE.Lazy

Inherited from GE

Inherited from UGenSource[UGenInLike]

Inherited from Expander[UGenInLike]

Inherited from Lazy

Inherited from Product

Inherited from Equals

Inherited from AnyRef

Inherited from Any

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