Audio Configuration

Configure audio capture, Opus encoding, WASAPI settings, and latency optimization

Overview

The host.audio section controls audio capture from the target process or system, Opus encoding parameters, WASAPI configuration, and latency optimization.

Process-Specific Audio Capture

Capture audio only from the target process instead of all system audio (requires Windows 11+).

audio.processLoopback.enabled · boolean · default: "true"

Enable process-specific loopback audio capture.

Default: true

When enabled, only audio from the target process is captured. When disabled, all system audio is captured.

Requires Windows 11 or later. Falls back to system audio capture on older Windows versions.

audio.processLoopback.includeProcessTree · boolean · default: "true"

Include audio from child processes of the target.

Default: true

Useful when the main application spawns child processes that also produce audio.

Opus Encoding

audio.bitrate · integer · default: "80000"

Opus encoding bitrate in bits per second.

Default: 80000 (80 kbps)

Recommended ranges:

• 64000 (64 kbps) - Minimum quality
• 80000 (80 kbps) - Good quality (default)
• 128000 (128 kbps) - High quality
• 192000 (192 kbps) - Maximum quality

80 kbps provides excellent quality for most use cases. Increase for music-focused applications.

audio.complexity · integer · default: "6"

Opus encoder computational complexity.

Default: 6

Range: 0 (lowest CPU) to 10 (highest CPU)

Higher values improve quality at the same bitrate but use more CPU.

audio.application · integer · default: "2049"

Opus application type.

Default: 2049 (OPUS_APPLICATION_AUDIO)

Options:

• 2048 - VOIP (optimized for speech)
• 2049 - AUDIO (general purpose, music)
• 2051 - RESTRICTED_LOWDELAY (lowest latency)

audio.channels · integer · default: "2"

Number of audio channels.

Default: 2 (stereo)

• 1 - Mono
• 2 - Stereo

audio.frameSizeMs · integer · default: "10"

Opus frame size in milliseconds.

Default: 10 ms

Options: 2.5, 5, 10, 20, 40, 60

Smaller values reduce latency but increase overhead. 10 ms is optimal for low-latency streaming.

Error Resilience

audio.enableFec · boolean · default: "true"

Enable Forward Error Correction (FEC) in Opus encoder.

Default: true

FEC embeds redundant data to recover from packet loss. Slightly increases bitrate.

Keep enabled for network streaming. Only disable on perfect local networks.

audio.expectedLossPerc · integer · default: "5"

Expected packet loss percentage for FEC tuning.

Default: 5 (%)

Higher values increase FEC overhead but improve resilience.

audio.enableDtx · boolean · default: "false"

Enable Discontinuous Transmission (DTX).

Default: false

Reduces bitrate during silence by not encoding silent frames. Can cause audio artifacts in gaming.

WASAPI Configuration

Windows Audio Session API (WASAPI) settings for low-level audio capture.

audio.wasapi.preferExclusiveMode · boolean · default: "false"

Prefer WASAPI exclusive mode.

Default: false

Exclusive mode provides lower latency but prevents other applications from using the audio device.

May conflict with other audio applications. Only enable if you need absolute minimum latency.

audio.wasapi.enforceEventDriven · boolean · default: "true"

Use event-driven WASAPI mode.

Default: true

Event-driven mode is more efficient than polling and provides lower latency.

audio.wasapi.devicePeriodMs · float · default: "5.0"

Target device period in milliseconds.

Default: 5.0 ms

Lower values reduce latency but increase CPU usage and risk of audio glitches.

audio.wasapi.fallbackPeriodMs · float · default: "10.0"

Fallback period if target period is not supported.

Default: 10.0 ms

audio.wasapi.force48kHzStereo · boolean · default: "true"

Force 48 kHz stereo capture format.

Default: true

48 kHz is optimal for Opus encoding. Resampling occurs if source is different.

audio.wasapi.preferLinearResampling · boolean · default: "true"

Use linear resampling instead of higher quality algorithms.

Default: true

Linear resampling has lower latency. Set to false for better quality at cost of latency.

audio.wasapi.useDmoOnlyForHighQuality · boolean · default: "false"

Only use DirectX Media Objects (DMO) for high-quality resampling.

Default: false

Latency Optimization

Advanced latency tuning for ultra-low-latency scenarios.

audio.latency.enforceSingleFrameBuffering · boolean · default: "true"

Minimize buffering to single frame.

Default: true

Reduces latency but requires consistent system performance.

audio.latency.maxFrameSizeMs · integer · default: "10"

Maximum frame size in milliseconds.

Default: 10 ms

Should match frameSizeMs for lowest latency.

audio.latency.minFrameSizeMs · integer · default: "10"

Minimum frame size in milliseconds.

Default: 10 ms

audio.latency.strictLatencyMode · boolean · default: "false"

Enable strict latency mode with aggressive buffering reduction.

Default: false

May cause audio glitches on slower systems. Only enable for ultra-low-latency requirements.

audio.latency.warnOnBuffering · boolean · default: "true"

Log warnings when buffering exceeds target.

Default: true

Useful for diagnosing audio latency issues.

audio.latency.targetOneWayLatencyMs · integer · default: "40"

Target one-way audio latency in milliseconds.

Default: 40 ms

End-to-end latency target including capture, encode, network, and decode.

audio.latency.ultraLowLatencyProfile · boolean · default: "false"

Enable ultra-low-latency profile with all optimizations.

Default: false

Applies aggressive settings for minimum latency. May reduce quality.

audio.latency.disableFecInLowLatency · boolean · default: "false"

Disable FEC in ultra-low-latency mode.

Default: false

Trades error resilience for lower latency.

Adaptive Bitrate Control

Dynamic audio bitrate adjustment based on network conditions.

audio.bitrateAdaptation.enabled · boolean · default: "true"

Enable adaptive audio bitrate control.

Default: true

Automatically adjusts bitrate based on packet loss and network quality.

audio.bitrateAdaptation.minBitrate · integer · default: "64000"

Minimum bitrate in bps.

Default: 64000 (64 kbps)

audio.bitrateAdaptation.maxBitrate · integer · default: "128000"

Maximum bitrate in bps.

Default: 128000 (128 kbps)

audio.bitrateAdaptation.decreaseCooldownMs · integer · default: "2000"

Cooldown period after bitrate decrease.

Default: 2000 ms

audio.bitrateAdaptation.increaseIntervalMs · integer · default: "10000"

Interval between bitrate increases.

Default: 10000 ms

audio.bitrateAdaptation.increaseStep · integer · default: "8000"

Bitrate increase step size in bps.

Default: 8000 (8 kbps)

audio.bitrateAdaptation.highLossThreshold · float · default: "0.05"

Packet loss threshold to trigger bitrate decrease.

Default: 0.05 (5%)

audio.bitrateAdaptation.lowLossThreshold · float · default: "0.01"

Packet loss threshold to allow bitrate increase.

Default: 0.01 (1%)

audio.bitrateAdaptation.cleanSamplesRequired · integer · default: "30"

Number of clean samples before increasing bitrate.

Default: 30

audio.bitrateAdaptation.fecEnableThreshold · float · default: "0.03"

Packet loss threshold to enable FEC.

Default: 0.03 (3%)

audio.bitrateAdaptation.fecDisableThreshold · float · default: "0.005"

Packet loss threshold to disable FEC.

Default: 0.005 (0.5%)

Threading

audio.useThreadAffinity · boolean · default: "false"

Pin audio encoder thread to specific CPU cores.

Default: false

audio.encoderThreadAffinityMask · integer · default: "0"

CPU affinity mask for encoder thread (bitmask of CPU cores).

Default: 0 (no affinity)

Example: 0x0F pins to first 4 cores.

Example Configurations

Low Latency Gaming

{
  "audio": {
    "processLoopback": {
      "enabled": true,
      "includeProcessTree": true
    },
    "bitrate": 64000,
    "complexity": 4,
    "frameSizeMs": 10,
    "enableFec": true,
    "latency": {
      "enforceSingleFrameBuffering": true,
      "strictLatencyMode": true,
      "ultraLowLatencyProfile": true
    }
  }
}

High Quality Music Streaming

{
  "audio": {
    "processLoopback": {
      "enabled": true
    },
    "bitrate": 128000,
    "complexity": 10,
    "frameSizeMs": 20,
    "enableFec": true,
    "bitrateAdaptation": {
      "enabled": true,
      "minBitrate": 96000,
      "maxBitrate": 192000
    }
  }
}

Unreliable Network

{
  "audio": {
    "bitrate": 80000,
    "enableFec": true,
    "expectedLossPerc": 10,
    "bitrateAdaptation": {
      "enabled": true,
      "highLossThreshold": 0.08,
      "fecEnableThreshold": 0.02
    }
  }
}