Integrations

discord.js compatibility

GitHub Edit page

discord.js compatibility

libopus-wasm/discordjs exposes an OpusEncoder class that matches the method shape of @discordjs/opus. It lets you swap a native addon for a WASM build without a node-gyp toolchain, prebuilt binaries, or platform-specific install steps.

This entry point uses node:buffer and is Node-only. For browsers, use the main libopus-wasm entry directly.

#The one difference: it loads asynchronously

@discordjs/opus builds its encoder synchronously in the constructor. WASM compiles asynchronously, so the adapter has to as well. There are two ways to wait for it.

import { OpusEncoder } from "libopus-wasm/discordjs";

const opus = await OpusEncoder.create(48000, 2);

const packet = opus.encode(pcmBuffer); // Buffer
const frame = opus.decode(packet);     // Buffer
opus.free();

#Or construct and await ready

This keeps new OpusEncoder(...) calls compatible with existing code:

const opus = new OpusEncoder(48000, 2);
await opus.ready;

opus.encode(pcmBuffer);

If you call a method before initialization finishes, it throws rather than returning garbage. If initialization itself fails (for example, an unsupported sample rate), ready rejects and the synchronous methods throw an error whose cause is the original failure.

#API

OpusEncoder mirrors the @discordjs/opus surface:

MemberDescription
new OpusEncoder(rate?, channels?)Construct; defaults 48000, 2. Then await ready.
OpusEncoder.create(rate?, channels?)Async factory; resolves when ready.
encode(buf)Encode a PCM Buffer/Uint8Array to an Opus Buffer.
decode(buf)Decode an Opus Buffer/Uint8Array to a PCM Buffer.
setBitrate(bitrate) / getBitrate()Bits per second.
setFEC(enabled)Toggle in-band FEC.
setPLP(percentage)Set expected packet-loss percentage (0–100).
applyEncoderCTL(ctl, value)Raw encoder CTL passthrough.
applyDecoderCTL(ctl, value)Raw decoder CTL passthrough.
free()Release the underlying encoder and decoder.
readyPromise<void> that resolves when the codec is usable.

encode infers the frame size from the buffer length and channel count, exactly like the native addon, so existing voice code that hands it 20 ms frames keeps working.

#Migrating

// Before
import { OpusEncoder } from "@discordjs/opus";
const opus = new OpusEncoder(48000, 2);

// After
import { OpusEncoder } from "libopus-wasm/discordjs";
const opus = await OpusEncoder.create(48000, 2);
const packet = opus.encode(frame);
const pcm = opus.decode(packet);
opus.applyEncoderCTL(EncoderCtl.SetBitrate, 64000);
opus.setFEC(true);
opus.setPLP(10);

The CTL codes are the same integers as @discordjs/opus; import the EncoderCtl / DecoderCtl enums from libopus-wasm for readable names.

#When to use the main API instead

The adapter trades flexibility for familiarity. If you are writing new code, or need Float32 PCM, explicit frame sizes, batch helpers, or browser support, use the main libopus-wasm API — it is a superset of what the adapter offers.

#Next