const SAMPLE_RATE = 48000;
const FRAME = 20;
const CHANNELS = 2;

await Opus.load();

// Optimize encoding for audio. Available applications are VOIP, AUDIO, and RESTRICTED_LOWDELAY
let encoder = new Opus(SAMPLE_RATE, CHANNELS, OpusApplication.AUDIO);

let frameSize = SAMPLE_RATE * FRAME / 1000;

// Get PCM data from somewhere and encode it into opus
let pcmData = new Uint8Array();
let encodedPacket = encoder.encode(pcmData, frameSize);

// Decode the opus packet back into PCM
let decodedPacket = encoder.decode(encodedPacket);
console.log(decodedPacket);

// Delete the encoder when finished with it (Emscripten does not automatically call C++ object destructors)
encoder.delete();