Package Exports

audio-spectrogram.ts
audio-spectrogram.ts/dist/core.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (audio-spectrogram.ts) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

audio-spectrogram.ts

Interactive tool for turning audio files into spectrogram visualisations in the browser.

Live demo

Features

Upload an audio file and inspect the generated spectrogram
Switch between precision profiles to tune performance vs. detail
Adjust the maximum frequency shown in the chart

TypeScript API

import {
  AudioProfileMode,
  DrawProgress,
  decodeAudio,
  drawSpectrogram,
  getAudioProfile,
  getMonoAudioData,
  getNow,
  getSpectrogramData,
  loadFile,
  loadUrl,
} from 'audio-spectrogram'

loadFile(file: File) → Promise<ArrayBuffer>: read a user-selected file.
loadUrl(url: string) → Promise<ArrayBuffer>: fetch audio data remotely with error handling.
decodeAudio(buffer: ArrayBuffer, sampleRate?: number) → Promise<AudioBuffer>: decode PCM data using the Web Audio API.
getMonoAudioData(audio: AudioBuffer) → Float32Array: downmix multi-channel audio to mono.
getSpectrogramData(audio: Float32Array, windowSize: number) → number[][]: compute log-scaled magnitudes for each FFT window.
drawSpectrogram(options) → Promise<void>: render grayscale pixels onto a canvas while reporting optional onProgress callbacks.
getAudioProfile(mode: AudioProfileMode) → profile settings (sampleRate, windowSize, hopSize, maxFrequency).
AudioProfileMode: union of 'high-precision' | 'medium-precision' | 'low-precision'.
DrawProgress: { percent: number; etaMs: number | null }.

Development

npm install
npm run dev

Open index.html in a browser (or use your preferred dev server) to iterate on the UI.

License

This project is licensed with BSD-2-Clause

This is free, libre, and open-source software. It comes down to four essential freedoms [ref]:

The freedom to run the program as you wish, for any purpose
The freedom to study how the program works, and change it so it does your computing as you wish
The freedom to redistribute copies so you can help others
The freedom to distribute copies of your modified versions to others