Recording

Kodio provides two approaches to recording: a simple one-liner for timed recording, and a more flexible Recorder class for manual control.

Timed recording

The simplest way to record audio is with Kodio.record(). Pass a duration and Kodio handles the rest—starting, stopping, and packaging the audio into a recording.

val recording = Kodio.record(duration = 5.seconds)

You can also specify a quality preset to optimize for your use case:

val recording = Kodio.record(
    duration = 5.seconds,
    quality = AudioQuality.High  // 48 kHz stereo
)

Manual control

When you need to control when recording starts and stops (for example, based on user interaction), use the callback form of Kodio.record():

val recording = Kodio.record { recorder ->
    recorder.start()
    waitForUserStop()  // Your app logic
    recorder.stop()
    recorder.getRecording()
}

The lambda receives a Recorder instance and returns whatever the lambda returns—typically the recording itself.

Using Recorder directly

For maximum control, create a Recorder instance directly. This is useful when you need to:

Start and stop recording multiple times
Access live audio data
Manage the recorder's lifecycle explicitly

val recorder = Kodio.recorder(quality = AudioQuality.Standard)

recorder.use { r ->
    r.start()
    delay(5.seconds)
    r.stop()
    r.getRecording()?.saveAs(Path("audio.wav"))
}

The use extension ensures resources are properly released, even if an exception occurs.

Live audio processing

The Recorder provides a liveAudioFlow that emits audio chunks in real-time while recording. This is perfect for visualizations like waveforms or level meters.

recorder.liveAudioFlow?.collect { chunk ->
    val amplitude = calculateAmplitude(chunk)
    updateWaveform(amplitude)
}

Recorder API reference

Properties

isRecording: Boolean: true while actively recording audio.
hasRecording: Boolean: true if a recording is available via getRecording().
quality: AudioQuality: The quality preset used for this recorder.
liveAudioFlow: Flow<ByteArray>?: Real-time audio data while recording. May be null on some platforms.
stateFlow: StateFlow<State>: Observable state changes for reactive UIs.

Methods

start(): Begin recording audio.
stop(): Stop recording. The recording becomes available via getRecording().
toggle(): Start if stopped, stop if recording. Convenient for single-button UIs.
reset(): Discard the current recording and prepare for a new one.
release(): Release all resources. Called automatically when using use {}.
getRecording(): AudioRecording?: Get the completed recording, or null if none available.

Last modified: 13 January 2026