A pure JavaScript, high-quality PCM audio resampler for Node.js. Converts s16le PCM between arbitrary sample rates and channel layouts (mono/stereo) with windowed-sinc filtering.
npm install @eliware/resampler> A pure JavaScript, high-quality PCM audio resampler for Node.js. Converts s16le PCM between arbitrary sample rates and channel layouts (mono/stereo) with windowed-sinc filtering. Includes built-in volume control.
---
- Features
- Installation
- Usage
- ESM Example
- CommonJS Example
- API
- TypeScript
- License
- Pure JavaScript, no native dependencies
- High-quality windowed-sinc resampling
- Arbitrary input/output sample rates (e.g. 48kHz ↔ 24kHz)
- Channel mixing: stereo→mono (average), mono→stereo (duplicate)
- Streams API: drop-in replacement for ffmpeg pipes in Node.js
- Supports s16le PCM (signed 16-bit little-endian)
- Built-in output volume control
- TypeScript type definitions included
``bash`
npm install @eliware/resampler
`js
import { Resampler } from '@eliware/resampler';
import fs from 'fs';
// Downsample 48kHz stereo to 24kHz mono
const resampler = new Resampler({ inRate: 48000, outRate: 24000, inChannels: 2, outChannels: 1 });
fs.createReadStream('input-48k-stereo.s16le')
.pipe(resampler)
.pipe(fs.createWriteStream('output-24k-mono.s16le'));
// Downsample with half volume
const resamplerQuiet = new Resampler({ inRate: 48000, outRate: 24000, inChannels: 2, outChannels: 1, volume: 0.5 });
fs.createReadStream('input-48k-stereo.s16le')
.pipe(resamplerQuiet)
.pipe(fs.createWriteStream('output-24k-mono-quiet.s16le'));
`
`js
const { Resampler } = require('@eliware/resampler');
const fs = require('fs');
// Upsample 24kHz mono to 48kHz stereo
const resampler = new Resampler({ inRate: 24000, outRate: 48000, inChannels: 1, outChannels: 2 });
fs.createReadStream('input-24k-mono.s16le')
.pipe(resampler)
.pipe(fs.createWriteStream('output-48k-stereo.s16le'));
// Upsample with lower volume
const resamplerQuiet = new Resampler({ inRate: 24000, outRate: 48000, inChannels: 1, outChannels: 2, volume: 0.2 });
fs.createReadStream('input-24k-mono.s16le')
.pipe(resamplerQuiet)
.pipe(fs.createWriteStream('output-48k-stereo-quiet.s16le'));
`
Creates a Transform stream that resamples s16le PCM audio.
#### Options
- inRate (number): Input sample rate (e.g. 48000)outRate
- (number): Output sample rate (e.g. 24000)inChannels
- (number, default 1): Number of input channels (1=mono, 2=stereo)outChannels
- (number, default 1): Number of output channels (1=mono, 2=stereo)filterWindow
- (number, default 8): Sinc filter window size (higher = better quality, more CPU)volume
- (number, default 1.0): Output volume multiplier (0.0 = silence, 1.0 = unchanged, >1.0 = amplify)
#### Example
`js`
const resampler = new Resampler({ inRate: 48000, outRate: 24000, inChannels: 2, outChannels: 1, volume: 0.5 });
Pipe PCM data through the resampler:
`js`
inputStream.pipe(resampler).pipe(outputStream);
Type definitions are included:
`ts
import { Resampler, ResamplerOptions } from '@eliware/resampler';
const resampler: Resampler = new Resampler({
inRate: 48000,
outRate: 24000,
inChannels: 2,
outChannels: 1,
volume: 0.5,
});
``
For help, questions, or to chat with the author and community, visit:
MIT © 2025 Eli Sterling, eliware.org