@webtrack/smp

Uses Web Audio API to playback *.smp/*.raw PCM files in the browser.

Intends to support samples created with Protracker, Fasttracker II etc.

Usage

npm install -S @webtrack/smp
# yarn add @webtrack/smp
# pnpm add @webtrack/smp

You'll need to load a sample file into the browser. Likely fetching from a remote resource:

import { Smp } from "@webtrack/smp";

const source = await fetch("/cool-sound.smp").then((res) => res.arrayBuffer());

const sample = new Smp({ src: source });
sample.play();

A working example can be found in the example app.

A live version is hosted at https://webtrack.vercel.app/

API

Constructor new Smp(options?)

Options:

• src: A typed array or ArrayBuffer of the sample file
• bitDepth: (Default, '8') The bit depth of the sample. Either 8, 16, 32 or 32 Float. Indicative of the typed array. An 8 bit depth PCM sample data would be stored in an Int8Array.
• sampleRate: (Default, 11025) The sample rate the sample should be played back with. Altering this will affect the speed and pitch of playback.
• loop: (Default, false) Whether the sample should loop or not.

.loadData(options)

Load a sample file in preparation to play

Options:

• src: A typed array or ArrayBuffer of the sample file
• bitDepth: (Default, '8') The bit depth of the sample. Either 8, 16, 32 or 32 Float. Indicative of the typed array. An 8 bit depth PCM sample data would be stored in an Int8Array.
• sampleRate: (Default, 11025) The sample rate the sample should be played back with. Altering this will affect the speed and pitch of playback.
• loop: (Default, false) Whether the sample should loop or not.

.play()

Play/resume the currently loaded sample

.pause()

Pauses playback of the sample

.stop()

Stops playback of the current sample. Playing again will resume from the start.

.setVolume(volume)

Sets the current volume of the sample. The value is between 1 and 0. 1 being 100%, 0.5 being 50% etc.