Tone.js/Tone/component/analysis/FFT.ts
2019-10-31 15:43:16 -04:00

79 lines
2.3 KiB
TypeScript

import { ToneAudioNode } from "../../core/context/ToneAudioNode";
import { dbToGain } from "../../core/type/Conversions";
import { NormalRange, PowerOfTwo } from "../../core/type/Units";
import { optionsFromArguments } from "../../core/util/Defaults";
import { MeterBase, MeterBaseOptions } from "./MeterBase";
export interface FFTOptions extends MeterBaseOptions {
size: PowerOfTwo;
smoothing: NormalRange;
normalRange: boolean;
}
/**
* Get the current frequency data of the connected audio source using a fast Fourier transform.
* @category Component
*/
export class FFT extends MeterBase<FFTOptions> {
readonly name: string = "FFT";
/**
* 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
*/
normalRange: boolean;
/**
* @param size The size of the FFT. Value must be a power of two in the range 16 to 16384.
*/
constructor(size?: PowerOfTwo);
constructor(options?: Partial<FFTOptions>);
constructor() {
super(optionsFromArguments(FFT.getDefaults(), arguments, ["size"]));
const options = optionsFromArguments(FFT.getDefaults(), arguments, ["size"]);
this.normalRange = options.normalRange;
this._analyser.type = "fft";
this.size = options.size;
}
static getDefaults(): FFTOptions {
return Object.assign(ToneAudioNode.getDefaults(), {
normalRange: false,
size: 1024,
smoothing: 0.8,
});
}
/**
* Gets the current frequency data from the connected audio source.
* Returns the frequency data of length [[size]] as a Float32Array of decibel values.
*/
getValue(): Float32Array {
return this._analyser.getValue().map(v => this.normalRange ? dbToGain(v) : v);
}
/**
* 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.
*/
get size(): PowerOfTwo {
return this._analyser.size;
}
set size(size) {
this._analyser.size = size;
}
/**
* 0 represents no time averaging with the last analysis frame.
*/
get smoothing(): NormalRange {
return this._analyser.smoothing;
}
set smoothing(val) {
this._analyser.smoothing = val;
}
}