Class AlsaIn

Namespace

NAudio.Wave.Alsa

Assembly

NAudio.Alsa.dll

An IWaveIn that records audio through ALSA on Linux.

public sealed class AlsaIn : IWaveIn, IDisposable, IWaveLatency

Inheritance

object

AlsaIn

Implements

IWaveIn

IDisposable

IWaveLatency

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

A dedicated background thread performs blocking snd_pcm_readi calls, recovers from overruns, and raises DataAvailable for each captured period. The thread is always joined before the device handle is closed.

Constructors

AlsaIn()

Creates an AlsaIn on the default PCM device.

public AlsaIn()

AlsaIn(string)

Creates an AlsaIn on a specific PCM device.

public AlsaIn(string device)

Parameters

device string

An ALSA PCM name, e.g. "default" or "hw:0".

Properties

AverageLatency

The steady-state latency from a sample being queued for output to it being emitted by the audio hardware, assuming uninterrupted playback. This is a property of the buffer configuration and the driver, not of the current playback state.

public TimeSpan AverageLatency { get; }

Property Value

TimeSpan

Remarks

The ring buffer is configured at StartRecording() time as PeriodFrames × Periods, so the steady-state delay between a sample hitting the hardware and being delivered to DataAvailable subscribers is the full buffer's worth of frames.

CurrentLatency

The time that has elapsed since the sample currently emerging from the hardware was queued for output. In steady state this is approximately equal to AverageLatency; it differs during start-up, after an underrun, or when the host is filling buffers irregularly. Implementations that cannot meaningfully distinguish from the average are permitted to return AverageLatency.

public TimeSpan CurrentLatency { get; }

Property Value

TimeSpan

Remarks

Uses snd_pcm_delay, which on a capture stream returns the number of frames already captured and waiting to be read — exactly the age of the oldest unread sample. Falls back to AverageLatency when not running or the call fails.

WaveFormat

Recording WaveFormat

public WaveFormat WaveFormat { get; set; }

Property Value

WaveFormat

Methods

Dispose()

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

public void Dispose()

StartRecording()

Start Recording

public void StartRecording()

StopRecording()

Stop Recording

public void StopRecording()

Events

DataAvailable

Indicates recorded data is available

public event EventHandler<WaveInEventArgs> DataAvailable

Event Type

EventHandler<WaveInEventArgs>

RecordingStopped

Indicates that all recorded data has now been received.

public event EventHandler<StoppedEventArgs> RecordingStopped

Event Type

EventHandler<StoppedEventArgs>