Device Selection

Kodio allows you to enumerate audio devices and direct recording or playback to specific hardware.

List available devices

Query the system for available audio devices:

// Input devices (microphones)
val inputs = Kodio.listInputDevices()
inputs.forEach { device ->
    println("🎤 ${device.name} (${device.id})")
}

// Output devices (speakers, headphones)
val outputs = Kodio.listOutputDevices()
outputs.forEach { device ->
    println("🔊 ${device.name} (${device.id})")
}

Each device has:

id: Unique identifier
name: Human-readable name (e.g., "Built-in Microphone", "AirPods Pro")

Record from a specific device

Use an external microphone or other input device:

val inputs = Kodio.listInputDevices()
val externalMic = inputs.find { it.name.contains("USB") }

val recording = Kodio.record(
    duration = 5.seconds,
    device = externalMic  // null uses system default
)

Play to a specific device

Route audio to headphones, speakers, or other output devices:

val outputs = Kodio.listOutputDevices()
val headphones = outputs.find { it.name.contains("Headphones") }

Kodio.play(recording, device = headphones)

In Compose

Pass the device to rememberRecorderState:

@Composable
fun DeviceSelector() {
    var selectedDevice by remember { mutableStateOf<AudioDevice?>(null) }
    val devices = remember { Kodio.listInputDevices() }
    
    // Device picker
    DropdownMenu(/* ... */) {
        devices.forEach { device ->
            DropdownMenuItem(
                text = { Text(device.name) },
                onClick = { selectedDevice = device }
            )
        }
    }
    
    // Recorder with selected device
    val recorderState = rememberRecorderState(
        device = selectedDevice
    )
    
    // ...
}

Platform support

Device selection support varies by platform:

Platform	Support	Notes
☕ JVM	✅ Full	Complete device enumeration
🍏 macOS	✅ Full	Complete device enumeration
🍎 iOS	✅ Full	AVAudioSession routes
🤖 Android	⚠️ Limited	System manages routing; selection available via AudioManager
🌐 Web	⚠️ Limited	Browser-dependent; requires `getUserMedia` with constraints

Error handling

If a specified device is unavailable:

try {
    val recording = Kodio.record(
        duration = 5.seconds,
        device = specificMic
    )
} catch (e: AudioError.DeviceNotFound) {
    // Device was disconnected or unavailable
    showError("Microphone not found. Using default.")
    val recording = Kodio.record(duration = 5.seconds)
}

Last modified: 13 January 2026