Spectrum Analyzer API

Real-time audio frequency analysis with windowing and dB conversion.

createSpectrumAnalyzer() is currently a CPU-only utility. It does not use the GPU FFT engine internally.

createSpectrumAnalyzer()

Creates a spectrum analyzer instance.

Signature

function createSpectrumAnalyzer(
  config: SpectrumAnalyzerConfig
): SpectrumAnalyzer;

Example

import { createSpectrumAnalyzer, WindowType } from 'webgpu-fft';

const analyzer = createSpectrumAnalyzer({
  fftSize: 2048,
  windowType: 'hann',
  sampleRate: 44100,
});

SpectrumAnalyzer Class

Methods

analyze()

Analyzes an audio buffer and returns dB values.

analyze(buffer: Float32Array): Promise<Float32Array>;

Parameters:

• buffer — Audio samples (real-valued)

Returns: Float32Array — Magnitude in dB per frequency bin.

const audioBuffer = new Float32Array(2048);
// ... fill with audio samples from Web Audio API ...

const spectrum = await analyzer.analyze(audioBuffer);
// spectrum[i] is the dB value for bin i

getFrequency()

Returns the center frequency for one FFT bin.

getFrequency(binIndex: number): number;

console.log(analyzer.getFrequency(10));

getFrequencies()

Returns the frequency values for each bin.

getFrequencies(): Float32Array;

const frequencies = analyzer.getFrequencies();
console.log(`Bin 10 corresponds to ${frequencies[10]} Hz`);

dispose()

Releases resources.

dispose(): void;

SpectrumAnalyzerConfig Type

interface SpectrumAnalyzerConfig {
  /** FFT size (power of 2, default 2048) */
  fftSize: number;
  /** Window function type */
  windowType: WindowType;
  /** Audio sample rate in Hz (default 44100) */
  sampleRate: number;
}

WindowType Type

type WindowType = 'hann' | 'hamming' | 'blackman' | 'flattop' | 'rectangular';

Related

• Spectrum Analysis Tutorial — Usage guide
• Window Functions — Window function details