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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())
         .setBufferSize(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

AudioRecord.Builder()

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

Public methods

AudioRecord build()
AudioRecord.Builder setAudioFormat(AudioFormat format)

Sets the format of the audio data to be captured.

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.

Inherited methods

Public constructors

AudioRecord.Builder

added in API level 23
public AudioRecord.Builder ()

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

Public methods

build

added in API level 23
public AudioRecord build ()

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, or if they are not supported by the device, 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
IllegalArgumentException

setAudioSource

added in API level 23
public AudioRecord.Builder setAudioSource (int source)

Parameters
source int: the audio source. See MediaRecorder.AudioSource for the supported audio source definitions.

Returns
AudioRecord.Builder the same Builder instance.

Throws
IllegalArgumentException

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
IllegalArgumentException