AudioRecord.Builder


public static class AudioRecord.Builder
extends Object

java.lang.Object
   ↳ android.media.AudioRecord.Builder


Builder class for AudioRecord objects. Use this class to configure and create an AudioRecord instance. By setting the recording source and audio format parameters, you indicate which of those vary from the default behavior on the device.

Here is an example where Builder is used to specify all AudioFormat parameters, to be used by a new AudioRecord instance:

 AudioRecord recorder = new AudioRecord.Builder()
         .setAudioSource(MediaRecorder.AudioSource.VOICE_COMMUNICATION)
         .setAudioFormat(new AudioFormat.Builder()
                 .setEncoding(AudioFormat.ENCODING_PCM_16BIT)
                 .setSampleRate(32000)
                 .setChannelMask(AudioFormat.CHANNEL_IN_MONO)
                 .build())
         .setBufferSizeInBytes(2*minBuffSize)
         .build();
 

If the audio source is not set with setAudioSource(int), MediaRecorder.AudioSource#DEFAULT is used.
If the audio format is not specified or is incomplete, its channel configuration will be AudioFormat#CHANNEL_IN_MONO, and the encoding will be AudioFormat#ENCODING_PCM_16BIT. The sample rate will depend on the device actually selected for capture and can be queried with AudioRecord.getSampleRate() method.
If the buffer size is not specified with setBufferSizeInBytes(int), the minimum buffer size for the source is used.

Summary

Public constructors

Builder()

Constructs a new Builder with the default values as described above.

Public methods

AudioRecord build()


Requires Manifest.permission.RECORD_AUDIO

AudioRecord.Builder setAudioFormat(AudioFormat format)

Sets the format of the audio data to be captured.

AudioRecord.Builder setAudioPlaybackCaptureConfig(AudioPlaybackCaptureConfiguration config)

Sets the AudioRecord to record audio played by other apps.

AudioRecord.Builder setAudioSource(int source)
AudioRecord.Builder setBufferSizeInBytes(int bufferSizeInBytes)

Sets the total size (in bytes) of the buffer where audio data is written during the recording.

AudioRecord.Builder setContext(Context context)

Sets the context the record belongs to.

AudioRecord.Builder setPrivacySensitive(boolean privacySensitive)

Indicates that this capture request is privacy sensitive and that any concurrent capture is not permitted.

Inherited methods

Object clone()

Creates and returns a copy of this object.

boolean equals(Object obj)

Indicates whether some other object is "equal to" this one.

void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

final Class<?> getClass()

Returns the runtime class of this Object.

int hashCode()

Returns a hash code value for the object.

final void notify()

Wakes up a single thread that is waiting on this object's monitor.

final void notifyAll()

Wakes up all threads that are waiting on this object's monitor.

String toString()

Returns a string representation of the object.

final void wait(long timeoutMillis, int nanos)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait(long timeoutMillis)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait()

Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public constructors

Builder

Added in API level 23
public Builder ()

Constructs a new Builder with the default values as described above.

Public methods

build

Added in API level 23
public AudioRecord build ()


Requires Manifest.permission.RECORD_AUDIO

Returns
AudioRecord a new AudioRecord instance successfully initialized with all the parameters set on this Builder.

Throws
UnsupportedOperationException if the parameters set on the Builder were incompatible, if the parameters are not supported by the device, if the caller does not hold the appropriate permissions, or if the device was not available.

setAudioFormat

Added in API level 23
public AudioRecord.Builder setAudioFormat (AudioFormat format)

Sets the format of the audio data to be captured.

Parameters
format AudioFormat: a non-null AudioFormat instance

Returns
AudioRecord.Builder the same Builder instance.

Throws
java.lang.IllegalArgumentException
IllegalArgumentException

setAudioPlaybackCaptureConfig

Added in API level 29
public AudioRecord.Builder setAudioPlaybackCaptureConfig (AudioPlaybackCaptureConfiguration config)

Sets the AudioRecord to record audio played by other apps.

Parameters
config AudioPlaybackCaptureConfiguration: Defines what apps to record audio from (i.e., via either their uid or the type of audio). This value cannot be null.

Returns
AudioRecord.Builder This value cannot be null.

Throws
IllegalStateException if called in conjunction with setAudioSource(int).
NullPointerException if config is null.

setBufferSizeInBytes

Added in API level 23
public AudioRecord.Builder setBufferSizeInBytes (int bufferSizeInBytes)

Sets the total size (in bytes) of the buffer where audio data is written during the recording. New audio data can be read from this buffer in smaller chunks than this size. See AudioRecord.getMinBufferSize(int, int, int) to determine the minimum required buffer size for the successful creation of an AudioRecord instance. Since bufferSizeInBytes may be internally increased to accommodate the source requirements, use AudioRecord.getBufferSizeInFrames() to determine the actual buffer size in frames.

Parameters
bufferSizeInBytes int: a value strictly greater than 0

Returns
AudioRecord.Builder the same Builder instance.

Throws
java.lang.IllegalArgumentException
IllegalArgumentException

setContext

Added in API level 31
public AudioRecord.Builder setContext (Context context)

Sets the context the record belongs to. This context will be used to pull information, such as AttributionSource and device specific session ids, which will be associated with the AudioRecord the AudioRecord. However, the context itself will not be retained by the AudioRecord.

Parameters
context Context: a non-null Context instance

Returns
AudioRecord.Builder the same Builder instance. This value cannot be null.

setPrivacySensitive

Added in API level 30
public AudioRecord.Builder setPrivacySensitive (boolean privacySensitive)

Indicates that this capture request is privacy sensitive and that any concurrent capture is not permitted.

The default is not privacy sensitive except when the audio source set with setAudioSource(int) is MediaRecorder.AudioSource#VOICE_COMMUNICATION or MediaRecorder.AudioSource#CAMCORDER.

Always takes precedence over default from audio source when set explicitly.

Using this API is only permitted when the audio source is one of:

Invoking build() will throw an UnsupportedOperationException if this condition is not met.

Parameters
privacySensitive boolean: True if capture from this AudioRecord must be marked as privacy sensitive, false otherwise.

Returns
AudioRecord.Builder This value cannot be null.

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Updated Apr 11, 2024