Skip to content
Smelter logo Smelter logo Smelter

Opus

Reference

Type definitions 

type OpusEncoderOptions = {
  type: "opus";
  preset?: "quality" | "voip" | "lowest_latency";
  sample_rate?: u32;
  forward_error_correction?: bool;
  expected_packet_loss?: u32;
}

Properties

preset

Audio output encoder preset.

  • Type: "quality" | "voip" | "lowest_latency"
  • Default value: voip
  • Supported values:
    • quality - Recommended for broadcast and high-fidelity applications requiring decoded audio to maintain maximum fidelity to the input signal.
    • voip - Recommended for VoIP and videoconferencing applications, prioritizing listening quality and speech intelligibility.
    • lowest_latency - Recommended only when achieving the lowest possible latency is the highest priority.

sample_rate

Sample rate.

  • Type: u32
  • Default value: 48000
  • Supported values: 8000, 16000, 24000, 48000

forward_error_correction

When enabled, include in-band forward error correction data to protect against packet loss. For more information, visit RFC specification sections 2.1.7 and 4.2.5

  • Type: bool
  • Default value: false

expected_packet_loss

Expected packet loss expressed as a percentage. This value controls how much redundant data is added to counteract packet loss (only when forward error correction is enabled).

  • Type: u32
  • Default value: 0
  • Supported values: 0-100