Cobra Binding for Node.js

Cobra Voice Activity Detection Engine

Made in Vancouver, Canada by Picovoice

Cobra is an on-device streaming voice activity detection engine. Cobra is:

• Private; All voice processing runs locally.
• Accurate [1]
• Cross-Platform:
  • Linux (x86_64), macOS (x86_64, arm64), and Windows (x86_64)
  • Android and iOS
  • Chrome, Safari, Firefox, and Edge
  • Raspberry Pi (2, 3, 4, 5) NVIDIA Jetson Nano, and BeagleBone

Compatibility

• Node.js 16+
• Runs on Linux (x86_64), macOS (x86_64, arm64), Windows (x86_64), Raspberry Pi (2, 3, 4, 5), NVIDIA Jetson Nano, and BeagleBone.

Installation

npm install @picovoice/cobra-node

AccessKey

Cobra requires a valid Picovoice AccessKey at initialization. AccessKey acts as your credentials when using Cobra SDKs. You can get your AccessKey for free. Make sure to keep your AccessKey secret. Signup or Login to Picovoice Console to get your AccessKey.

Usage

Create an instance of the engine and detect voice activity in the audio:

Replace ${AccessKey} with your AccessKey obtained from Picovoice Console. cobra is an instance of Cobra.

const { Cobra } = require("@picovoice/cobra-node");

const accessKey = "${ACCESS_KEY}"; // Obtained from the Picovoice Console (https://console.picovoice.ai/)
const cobra = new Cobra(accessKey);

Once initialized, the valid sample rate is given by cobra.sampleRate. The expected frame length (number of audio samples in an input array) is cobra.frameLength. The engine accepts 16-bit linearly-encoded PCM and operates on single-channel audio.

function getNextAudioFrame() {
  // ...
  return audioFrame;
}

while (true) {
  const audioFrame = getNextAudioFrame();
  const voiceProbability = cobra.process(audioFrame);
  console.log(voiceProbability);
}

Finally, when done be sure to explicitly release the resources using cobra.release().

Demos

The Cobra Node.js demo package provides command-line utilities for processing audio using Cobra.