Class FFT

Get the current frequency data of the connected audio source using a fast Fourier transform. Read more about FFT algorithms on [Wikipedia] (https://en.wikipedia.org/wiki/Fast_Fourier_transform).

Hierarchy

Constructors

constructor

Properties

context debug input name normalRange output version

Accessors

blockTime channelCount channelCountMode channelInterpretation disposed numberOfInputs numberOfOutputs sampleTime size smoothing

Methods

chain connect disconnect dispose fan get getFrequencyOfIndex getValue immediate now set toDestination toFrequency toMaster toSeconds toString toTicks getDefaults

Constructors

constructor

Properties

Readonly context

context: BaseContext

The context belonging to the node.

debug

debug: boolean = false

Set this debug flag to log all events that happen in this class.

input

input: InputNode

The signal to be analysed

Readonly name

name: string = "FFT"

normalRange

normalRange: boolean

If the output should be in decibels or normal range between 0-1. If normalRange is false, the output range will be the measured decibel value, otherwise the decibel value will be converted to the range of 0-1

output

output: OutputNode

The output is just a pass through of the input

Static version

version: string = version

The version number semver

Accessors

blockTime

  • get blockTime(): number

  • The number of seconds of 1 processing block (128 samples)

    Returns number

    Example

    console.log(Tone.Destination.blockTime);

channelCount

  • get channelCount(): number

  • channelCount is the number of channels used when up-mixing and down-mixing connections to any inputs to the node. The default value is 2 except for specific nodes where its value is specially determined.

    Returns number

  • set channelCount(channelCount): void

  • Parameters

    • channelCount: number

    Returns void

channelCountMode

  • get channelCountMode(): ChannelCountMode

  • channelCountMode determines how channels will be counted when up-mixing and down-mixing connections to any inputs to the node. The default value is "max". This attribute has no effect for nodes with no inputs.

    • "max" - computedNumberOfChannels is the maximum of the number of channels of all connections to an input. In this mode channelCount is ignored.
    • "clamped-max" - computedNumberOfChannels is determined as for "max" and then clamped to a maximum value of the given channelCount.
    • "explicit" - computedNumberOfChannels is the exact value as specified by the channelCount.

    Returns ChannelCountMode

  • set channelCountMode(channelCountMode): void

  • Parameters

    • channelCountMode: ChannelCountMode

    Returns void

channelInterpretation

  • get channelInterpretation(): ChannelInterpretation

  • channelInterpretation determines how individual channels will be treated when up-mixing and down-mixing connections to any inputs to the node. The default value is "speakers".

    Returns ChannelInterpretation

  • set channelInterpretation(channelInterpretation): void

  • Parameters

    • channelInterpretation: ChannelInterpretation

    Returns void

disposed

  • get disposed(): boolean

  • Indicates if the instance was disposed. 'Disposing' an instance means that all of the Web Audio nodes that were created for the instance are disconnected and freed for garbage collection.

    Returns boolean

numberOfInputs

  • get numberOfInputs(): number

  • The number of inputs feeding into the AudioNode. For source nodes, this will be 0.

    Returns number

    Example

    const node = new Tone.Gain();
    console.log(node.numberOfInputs);

numberOfOutputs

  • get numberOfOutputs(): number

  • The number of outputs of the AudioNode.

    Returns number

    Example

    const node = new Tone.Gain();
    console.log(node.numberOfOutputs);

sampleTime

size

  • get size(): number

  • The size of analysis. This must be a power of two in the range 16 to 16384. Determines the size of the array returned by getValue (i.e. the number of frequency bins). Large FFT sizes may be costly to compute.

    Returns number

  • set size(size): void

  • Parameters

    • size: number

    Returns void

smoothing

Methods

chain

  • chain(...nodes): this

  • Connect the output of this node to the rest of the nodes in series.

    Parameters

    Returns this

    Example

    const player = new Tone.Player("https://tonejs.github.io/audio/drum-samples/handdrum-loop.mp3");
    player.autostart = true;
    const filter = new Tone.AutoFilter(4).start();
    const distortion = new Tone.Distortion(0.5);
    // connect the player to the filter, distortion and then to the master output
    player.chain(filter, distortion, Tone.Destination);

connect

  • connect(destination, outputNum?, inputNum?): this

  • connect the output of a ToneAudioNode to an AudioParam, AudioNode, or ToneAudioNode

    Parameters

    • destination: InputNode

      The output to connect to

    • outputNum: number = 0

      The output to connect from

    • inputNum: number = 0

      The input to connect to

    Returns this

disconnect

  • disconnect(destination?, outputNum?, inputNum?): this

  • disconnect the output

    Parameters

    • Optional destination: InputNode
    • outputNum: number = 0
    • inputNum: number = 0

    Returns this

dispose

fan

  • fan(...nodes): this

  • connect the output of this node to the rest of the nodes in parallel.

    Parameters

    Returns this

    Example

    const player = new Tone.Player("https://tonejs.github.io/audio/drum-samples/conga-rhythm.mp3");
    player.autostart = true;
    const pitchShift = new Tone.PitchShift(4).toDestination();
    const filter = new Tone.Filter("G5").toDestination();
    // connect a node to the pitch shift and filter in parallel
    player.fan(pitchShift, filter);

get

getFrequencyOfIndex

  • getFrequencyOfIndex(index): number

  • Returns the frequency value in hertz of each of the indices of the FFT's getValue response.

    Parameters

    • index: number

    Returns number

    Example

    const fft = new Tone.FFT(32);
    console.log([0, 1, 2, 3, 4].map(index => fft.getFrequencyOfIndex(index)));

getValue

  • getValue(): Float32Array

  • Gets the current frequency data from the connected audio source. Returns the frequency data of length size as a Float32Array of decibel values.

    Returns Float32Array

immediate

  • immediate(): number

  • Return the current time of the Context clock without any lookAhead.

    Returns number

    Example

    setInterval(() => {
        console.log(Tone.immediate());
    }, 100);

now

  • now(): number

  • Return the current time of the Context clock plus the lookAhead.

    Returns number

    Example

    setInterval(() => {
        console.log(Tone.now());
    }, 100);

set

  • set(props): this

  • Set multiple properties at once with an object.

    Parameters

    Returns this

    Example

    const filter = new Tone.Filter().toDestination();
    // set values using an object
    filter.set({
        frequency: "C6",
        type: "highpass"
    });
    const player = new Tone.Player("https://tonejs.github.io/audio/berklee/Analogsynth_octaves_highmid.mp3").connect(filter);
    player.autostart = true;

toDestination

  • toDestination(): this

  • Connect the output to the context's destination node.

    Returns this

    Example

    const osc = new Tone.Oscillator("C2").start();
    osc.toDestination();

toFrequency

  • toFrequency(freq): number

  • Convert the input to a frequency number

    Parameters

    Returns number

    Example

    const gain = new Tone.Gain();
    console.log(gain.toFrequency("4n"));

toMaster

toSeconds

  • toSeconds(time?): number

  • Convert the incoming time to seconds. This is calculated against the current TransportClass bpm

    Parameters

    Returns number

    Example

    const gain = new Tone.Gain();
    setInterval(() => console.log(gain.toSeconds("4n")), 100);
    // ramp the tempo to 60 bpm over 30 seconds
    Tone.getTransport().bpm.rampTo(60, 30);

toString

  • toString(): string

  • Convert the class to a string

    Returns string

    Example

    const osc = new Tone.Oscillator();
    console.log(osc.toString());

toTicks

  • toTicks(time?): number

  • Convert the input time into ticks

    Parameters

    Returns number

    Example

    const gain = new Tone.Gain();
    console.log(gain.toTicks("4n"));

Static getDefaults

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constructorcontextdebuginputnamenormalRangeoutputversionblockTimechannelCountchannelCountModechannelInterpretationdisposednumberOfInputsnumberOfOutputssampleTimesizesmoothingchainconnectdisconnectdisposefangetgetFrequencyOfIndexgetValueimmediatenowsettoDestinationtoFrequencytoMastertoSecondstoStringtoTicksgetDefaults