Audio Recording
Node.js Quick Start

Platforms

• Linux (x86_64)
• macOS (x86_64, arm64)
• Windows (x86_64, arm64)
• Raspberry Pi (3, 4, 5)

Requirements

• Node.js 18+
• npm

Quick Start

Setup

1. Install Node.js.

2. Install the pvrecorder-node npm package:

npm install @picovoice/pvrecorder-node

Usage

Initialize and begin recording:

const { PvRecorder } = require("@picovoice/pvrecorder-node");

const frameLength = 512;
const recorder = new PvRecorder(frameLength);
recorder.start();

Read a frame of audio:

while (true) {
  const frame = await recorder.read();
  // process audio frame
}

To stop recording:

recorder.stop()

Once you are done, free the used resources. You do not have to call stop() before release():

recorder.release()

Selecting an Audio Device

To get a list of available audio devices:

const devices = PvRecorder.getAvailableDevices()

The index of the device in the returned list can be used in the constructor() to select that device for audio capture:

const recorder = PvRecorder(512, /*Device Index*/2)

Demo

For the PvRecorder Node.js SDK, we offer a demo application that demonstrates how use PvRecorder to record audio to an output audio file.

Setup

Install the PvRecorder demo package:

npm install -g @picovoice/pvrecorder-node-demo

This package installs command-line utilities for the PvRecorder Nodejs demo.

Usage

Use the --help flag to see the usage options for the demo:

pvrecorder-node-demo --help

Run the following to see what devices are available for audio capture:

pvrecorder-node-demo --show_audio_devices

Run the demo with the desired audio device (or -1 for the default one) and an output file path:

pvrecorder-node-demo --audio_device_index ${DEVICE_INDEX} --output_wav_path ${OUTPUT_WAV_PATH}

For more information about our PvRecorder demo for Node.js, head over to our GitHub repository.

Resources