Tone.js/Tone/component/analysis/Analyser.ts
2019-09-14 16:39:18 -04:00

116 lines
3 KiB
TypeScript

import { ToneAudioNode, ToneAudioNodeOptions } from "../../core/context/ToneAudioNode";
import { NormalRange, PowerOfTwo } from "../../core/type/Units";
import { optionsFromArguments } from "../../core/util/Defaults";
export type AnalyserType = "fft" | "waveform";
export interface AnalyserOptions extends ToneAudioNodeOptions {
size: PowerOfTwo;
type: AnalyserType;
smoothing: NormalRange;
}
/**
* Wrapper around the native Web Audio's [AnalyserNode](http://webaudio.github.io/web-audio-api/#idl-def-AnalyserNode).
* Extracts FFT or Waveform data from the incoming signal.
* @category Component
*/
export class Analyser extends ToneAudioNode<AnalyserOptions> {
readonly name: string = "Analyser";
readonly input: AnalyserNode;
readonly output: AnalyserNode;
/**
* The analyser node.
*/
private _analyser = this.context.createAnalyser();
/**
* The analysis type
*/
private _type!: AnalyserType;
/**
* The buffer that the FFT data is written to
*/
private _buffer!: Float32Array;
/**
* @param type The return type of the analysis, either "fft", or "waveform".
* @param size The size of the FFT. This must be a power of two in the range 16 to 16384.
*/
constructor(type?: AnalyserType, size?: number);
constructor(options?: Partial<AnalyserOptions>);
constructor() {
super(optionsFromArguments(Analyser.getDefaults(), arguments, ["type", "size"]));
const options = optionsFromArguments(Analyser.getDefaults(), arguments, ["type", "size"]);
// set the values initially
this.size = options.size;
this.type = options.type;
this.input = this.output = this._analyser;
}
static getDefaults(): AnalyserOptions {
return Object.assign(ToneAudioNode.getDefaults(), {
size: 1024,
smoothing: 0.8,
type: "fft" as AnalyserType,
});
}
/**
* Run the analysis given the current settings and return the
*/
getValue(): Float32Array {
if (this._type === "fft") {
this._analyser.getFloatFrequencyData(this._buffer);
} else if (this._type === "waveform") {
this._analyser.getFloatTimeDomainData(this._buffer);
}
return this._buffer;
}
/**
* The size of analysis. This must be a power of two in the range 16 to 16384.
*/
get size(): PowerOfTwo {
return this._analyser.frequencyBinCount;
}
set size(size: PowerOfTwo) {
this._analyser.fftSize = size * 2;
this._buffer = new Float32Array(size);
}
/**
* The analysis function returned by analyser.getValue(), either "fft" or "waveform".
*/
get type(): AnalyserType {
return this._type;
}
set type(type: AnalyserType) {
this.assert(type === "waveform" || type === "fft", `Analyser: invalid type: ${type}`);
this._type = type;
}
/**
* 0 represents no time averaging with the last analysis frame.
*/
get smoothing(): NormalRange {
return this._analyser.smoothingTimeConstant;
}
set smoothing(val: NormalRange) {
this._analyser.smoothingTimeConstant = val;
}
/**
* Clean up.
*/
dispose(): this {
super.dispose();
this._analyser.disconnect();
return this;
}
}