AudioRecord
public
class
AudioRecord
extends Object
implements
AudioRecordingMonitor,
AudioRouting,
MicrophoneDirection
java.lang.Object | |
↳ | android.media.AudioRecord |
The AudioRecord class manages the audio resources for Java applications
to record audio from the audio input hardware of the platform. This is
achieved by "pulling" (reading) the data from the AudioRecord object. The
application is responsible for polling the AudioRecord object in time using one of
the following three methods: read(byte[], int, int)
, read(short[], int, int)
or read(java.nio.ByteBuffer, int)
. The choice of which method to use will be based
on the audio data storage format that is the most convenient for the user of AudioRecord.
Upon creation, an AudioRecord object initializes its associated audio buffer that it will fill with the new audio data. The size of this buffer, specified during the construction, determines how long an AudioRecord can record before "over-running" data that has not been read yet. Data should be read from the audio hardware in chunks of sizes inferior to the total recording buffer size.
Applications creating an AudioRecord instance need
Manifest.permission.RECORD_AUDIO
or the Builder will throw
UnsupportedOperationException
on
build()
,
and the constructor will return an instance in state
STATE_UNINITIALIZED
.
Summary
Nested classes | |
---|---|
class |
AudioRecord.Builder
Builder class for |
class |
AudioRecord.MetricsConstants
|
interface |
AudioRecord.OnRecordPositionUpdateListener
Interface definition for a callback to be invoked when an AudioRecord has
reached a notification marker set by |
interface |
AudioRecord.OnRoutingChangedListener
This interface was deprecated
in API level 24.
users should switch to the general purpose
|
Constants | |
---|---|
int |
ERROR
Denotes a generic operation failure. |
int |
ERROR_BAD_VALUE
Denotes a failure due to the use of an invalid value. |
int |
ERROR_DEAD_OBJECT
An error code indicating that the object reporting it is no longer valid and needs to be recreated. |
int |
ERROR_INVALID_OPERATION
Denotes a failure due to the improper use of a method. |
int |
READ_BLOCKING
The read mode indicating the read operation will block until all data requested has been read. |
int |
READ_NON_BLOCKING
The read mode indicating the read operation will return immediately after reading as much audio data as possible without blocking. |
int |
RECORDSTATE_RECORDING
indicates AudioRecord recording state is recording |
int |
RECORDSTATE_STOPPED
indicates AudioRecord recording state is not recording |
int |
STATE_INITIALIZED
indicates AudioRecord state is ready to be used |
int |
STATE_UNINITIALIZED
indicates AudioRecord state is not successfully initialized. |
int |
SUCCESS
Denotes a successful operation. |
Inherited constants |
---|
Public constructors | |
---|---|
AudioRecord(int audioSource, int sampleRateInHz, int channelConfig, int audioFormat, int bufferSizeInBytes)
Class constructor. |
Public methods | |
---|---|
void
|
addOnRoutingChangedListener(AudioRecord.OnRoutingChangedListener listener, Handler handler)
This method was deprecated
in API level 24.
users should switch to the general purpose
|
void
|
addOnRoutingChangedListener(AudioRouting.OnRoutingChangedListener listener, Handler handler)
Adds an |
List<MicrophoneInfo>
|
getActiveMicrophones()
Returns a lists of |
AudioRecordingConfiguration
|
getActiveRecordingConfiguration()
Returns the current active audio recording for this audio recorder. |
int
|
getAudioFormat()
Returns the configured audio data encoding. |
int
|
getAudioSessionId()
Returns the audio session ID. |
int
|
getAudioSource()
Returns the audio recording source. |
int
|
getBufferSizeInFrames()
Returns the frame count of the native |
int
|
getChannelConfiguration()
Returns the configured channel position mask. |
int
|
getChannelCount()
Returns the configured number of channels. |
AudioFormat
|
getFormat()
Returns the configured |
LogSessionId
|
getLogSessionId()
Returns the |
PersistableBundle
|
getMetrics()
Return Metrics data about the current AudioTrack instance. |
static
int
|
getMinBufferSize(int sampleRateInHz, int channelConfig, int audioFormat)
Returns the minimum buffer size required for the successful creation of an AudioRecord object, in byte units. |
int
|
getNotificationMarkerPosition()
Returns the notification marker position expressed in frames. |
int
|
getPositionNotificationPeriod()
Returns the notification update period expressed in frames. |
AudioDeviceInfo
|
getPreferredDevice()
Returns the selected input specified by |
int
|
getRecordingState()
Returns the recording state of the AudioRecord instance. |
AudioDeviceInfo
|
getRoutedDevice()
Returns an |
int
|
getSampleRate()
Returns the configured audio sink sample rate in Hz. |
int
|
getState()
Returns the state of the AudioRecord instance. |
int
|
getTimestamp(AudioTimestamp outTimestamp, int timebase)
Poll for an |
boolean
|
isPrivacySensitive()
Returns whether this AudioRecord is marked as privacy sensitive or not. |
int
|
read(short[] audioData, int offsetInShorts, int sizeInShorts, int readMode)
Reads audio data from the audio hardware for recording into a short array. |
int
|
read(ByteBuffer audioBuffer, int sizeInBytes, int readMode)
Reads audio data from the audio hardware for recording into a direct buffer. |
int
|
read(short[] audioData, int offsetInShorts, int sizeInShorts)
Reads audio data from the audio hardware for recording into a short array. |
int
|
read(float[] audioData, int offsetInFloats, int sizeInFloats, int readMode)
Reads audio data from the audio hardware for recording into a float array. |
int
|
read(byte[] audioData, int offsetInBytes, int sizeInBytes, int readMode)
Reads audio data from the audio hardware for recording into a byte array. |
int
|
read(ByteBuffer audioBuffer, int sizeInBytes)
Reads audio data from the audio hardware for recording into a direct buffer. |
int
|
read(byte[] audioData, int offsetInBytes, int sizeInBytes)
Reads audio data from the audio hardware for recording into a byte array. |
void
|
registerAudioRecordingCallback(Executor executor, AudioManager.AudioRecordingCallback cb)
Register a callback to be notified of audio capture changes via a
|
void
|
release()
Releases the native AudioRecord resources. |
void
|
removeOnRoutingChangedListener(AudioRecord.OnRoutingChangedListener listener)
This method was deprecated
in API level 24.
users should switch to the general purpose
|
void
|
removeOnRoutingChangedListener(AudioRouting.OnRoutingChangedListener listener)
Removes an |
void
|
setLogSessionId(LogSessionId logSessionId)
Sets a |
int
|
setNotificationMarkerPosition(int markerInFrames)
Sets the marker position at which the listener is called, if set with
|
int
|
setPositionNotificationPeriod(int periodInFrames)
Sets the period at which the listener is called, if set with
|
boolean
|
setPreferredDevice(AudioDeviceInfo deviceInfo)
Specifies an audio device (via an |
boolean
|
setPreferredMicrophoneDirection(int direction)
Specifies the logical microphone (for processing). |
boolean
|
setPreferredMicrophoneFieldDimension(float zoom)
Specifies the zoom factor (i.e. |
void
|
setRecordPositionUpdateListener(AudioRecord.OnRecordPositionUpdateListener listener)
Sets the listener the AudioRecord notifies when a previously set marker is reached or for each periodic record head position update. |
void
|
setRecordPositionUpdateListener(AudioRecord.OnRecordPositionUpdateListener listener, Handler handler)
Sets the listener the AudioRecord notifies when a previously set marker is reached or for each periodic record head position update. |
void
|
startRecording(MediaSyncEvent syncEvent)
Starts recording from the AudioRecord instance when the specified synchronization event occurs on the specified audio session. |
void
|
startRecording()
Starts recording from the AudioRecord instance. |
void
|
stop()
Stops recording. |
void
|
unregisterAudioRecordingCallback(AudioManager.AudioRecordingCallback cb)
Unregister an audio recording callback previously registered with
|
Protected methods | |
---|---|
void
|
finalize()
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. |
Inherited methods | |
---|---|
Constants
ERROR
public static final int ERROR
Denotes a generic operation failure.
Constant Value: -1 (0xffffffff)
ERROR_BAD_VALUE
public static final int ERROR_BAD_VALUE
Denotes a failure due to the use of an invalid value.
Constant Value: -2 (0xfffffffe)
ERROR_DEAD_OBJECT
public static final int ERROR_DEAD_OBJECT
An error code indicating that the object reporting it is no longer valid and needs to be recreated.
Constant Value: -6 (0xfffffffa)
ERROR_INVALID_OPERATION
public static final int ERROR_INVALID_OPERATION
Denotes a failure due to the improper use of a method.
Constant Value: -3 (0xfffffffd)
READ_BLOCKING
public static final int READ_BLOCKING
The read mode indicating the read operation will block until all data requested has been read.
Constant Value: 0 (0x00000000)
READ_NON_BLOCKING
public static final int READ_NON_BLOCKING
The read mode indicating the read operation will return immediately after reading as much audio data as possible without blocking.
Constant Value: 1 (0x00000001)
RECORDSTATE_RECORDING
public static final int RECORDSTATE_RECORDING
indicates AudioRecord recording state is recording
Constant Value: 3 (0x00000003)
RECORDSTATE_STOPPED
public static final int RECORDSTATE_STOPPED
indicates AudioRecord recording state is not recording
Constant Value: 1 (0x00000001)
STATE_INITIALIZED
public static final int STATE_INITIALIZED
indicates AudioRecord state is ready to be used
Constant Value: 1 (0x00000001)
STATE_UNINITIALIZED
public static final int STATE_UNINITIALIZED
indicates AudioRecord state is not successfully initialized.
Constant Value: 0 (0x00000000)
SUCCESS
public static final int SUCCESS
Denotes a successful operation.
Constant Value: 0 (0x00000000)
Public constructors
AudioRecord
public AudioRecord (int audioSource, int sampleRateInHz, int channelConfig, int audioFormat, int bufferSizeInBytes)
Class constructor.
Though some invalid parameters will result in an IllegalArgumentException
exception,
other errors do not. Thus you should call getState()
immediately after construction
to confirm that the object is usable.
Requires Manifest.permission.RECORD_AUDIO
Parameters | |
---|---|
audioSource |
int : the recording source.
See MediaRecorder.AudioSource for the recording source definitions. |
sampleRateInHz |
int : the sample rate expressed in Hertz. 44100Hz is currently the only
rate that is guaranteed to work on all devices, but other rates such as 22050,
16000, and 11025 may work on some devices.
AudioFormat.SAMPLE_RATE_UNSPECIFIED means to use a route-dependent value
which is usually the sample rate of the source.
getSampleRate() can be used to retrieve the actual sample rate chosen. |
channelConfig |
int : describes the configuration of the audio channels.
See AudioFormat.CHANNEL_IN_MONO and
AudioFormat.CHANNEL_IN_STEREO . AudioFormat.CHANNEL_IN_MONO is guaranteed
to work on all devices. |
audioFormat |
int : the format in which the audio data is to be returned.
See AudioFormat.ENCODING_PCM_8BIT , AudioFormat.ENCODING_PCM_16BIT ,
and AudioFormat.ENCODING_PCM_FLOAT . |
bufferSizeInBytes |
int : the total size (in bytes) of the buffer where audio data is written
to during the recording. New audio data can be read from this buffer in smaller chunks
than this size. See getMinBufferSize(int, int, int) to determine the minimum
required buffer size for the successful creation of an AudioRecord instance. Using values
smaller than getMinBufferSize() will result in an initialization failure. |
Throws | |
---|---|
|
java.lang.IllegalArgumentException |
IllegalArgumentException |
Public methods
addOnRoutingChangedListener
public void addOnRoutingChangedListener (AudioRecord.OnRoutingChangedListener listener, Handler handler)
This method was deprecated
in API level 24.
users should switch to the general purpose
AudioRouting.OnRoutingChangedListener
class instead.
Adds an OnRoutingChangedListener
to receive notifications of routing changes
on this AudioRecord.
Parameters | |
---|---|
listener |
AudioRecord.OnRoutingChangedListener : The OnRoutingChangedListener interface to receive notifications
of rerouting events. |
handler |
Handler : Specifies the Handler object for the thread on which to execute
the callback. If null , the Handler associated with the main
Looper will be used. |
addOnRoutingChangedListener
public void addOnRoutingChangedListener (AudioRouting.OnRoutingChangedListener listener, Handler handler)
Adds an AudioRouting.OnRoutingChangedListener
to receive notifications of
routing changes on this AudioRecord.
Parameters | |
---|---|
listener |
AudioRouting.OnRoutingChangedListener : The AudioRouting.OnRoutingChangedListener interface to receive
notifications of rerouting events. |
handler |
Handler : Specifies the Handler object for the thread on which to execute
the callback. If null , the Handler associated with the main
Looper will be used. |
getActiveMicrophones
public List<MicrophoneInfo> getActiveMicrophones ()
Returns a lists of MicrophoneInfo
representing the active microphones.
By querying channel mapping for each active microphone, developer can know how
the microphone is used by each channels or a capture stream.
Note that the information about the active microphones may change during a recording.
See AudioManager.registerAudioDeviceCallback
to be notified of changes
in the audio devices, querying the active microphones then will return the latest
information.
Returns | |
---|---|
List<MicrophoneInfo> |
a lists of MicrophoneInfo representing the active microphones. |
Throws | |
---|---|
IOException |
if an error occurs |
getActiveRecordingConfiguration
public AudioRecordingConfiguration getActiveRecordingConfiguration ()
Returns the current active audio recording for this audio recorder.
Returns | |
---|---|
AudioRecordingConfiguration |
a valid AudioRecordingConfiguration if this recorder is active
or null otherwise. |
See also:
getAudioFormat
public int getAudioFormat ()
Returns the configured audio data encoding. See AudioFormat.ENCODING_PCM_8BIT
,
AudioFormat.ENCODING_PCM_16BIT
, and AudioFormat.ENCODING_PCM_FLOAT
.
Returns | |
---|---|
int |
getAudioSessionId
public int getAudioSessionId ()
Returns the audio session ID.
Returns | |
---|---|
int |
the ID of the audio session this AudioRecord belongs to. |
getAudioSource
public int getAudioSource ()
Returns the audio recording source.
Returns | |
---|---|
int |
See also:
getBufferSizeInFrames
public int getBufferSizeInFrames ()
Returns the frame count of the native AudioRecord
buffer.
This is greater than or equal to the bufferSizeInBytes converted to frame units
specified in the AudioRecord
constructor or Builder.
The native frame count may be enlarged to accommodate the requirements of the
source on creation or if the AudioRecord
is subsequently rerouted.
Returns | |
---|---|
int |
current size in frames of the AudioRecord buffer. |
Throws | |
---|---|
|
java.lang.IllegalStateException |
getChannelConfiguration
public int getChannelConfiguration ()
Returns the configured channel position mask.
See AudioFormat.CHANNEL_IN_MONO
and AudioFormat.CHANNEL_IN_STEREO
.
This method may return AudioFormat.CHANNEL_INVALID
if
a channel index mask is used.
Consider getFormat()
instead, to obtain an AudioFormat
,
which contains both the channel position mask and the channel index mask.
Returns | |
---|---|
int |
getChannelCount
public int getChannelCount ()
Returns the configured number of channels.
Returns | |
---|---|
int |
getFormat
public AudioFormat getFormat ()
Returns the configured AudioRecord
format.
Returns | |
---|---|
AudioFormat |
an AudioFormat containing the
AudioRecord parameters at the time of configuration.
This value cannot be null . |
getLogSessionId
public LogSessionId getLogSessionId ()
Returns the LogSessionId
.
Returns | |
---|---|
LogSessionId |
This value cannot be null . |
getMetrics
public PersistableBundle getMetrics ()
Return Metrics data about the current AudioTrack instance.
Returns | |
---|---|
PersistableBundle |
a PersistableBundle containing the set of attributes and values
available for the media being handled by this instance of AudioRecord
The attributes are descibed in MetricsConstants .
Additional vendor-specific fields may also be present in
the return value. |
getMinBufferSize
public static int getMinBufferSize (int sampleRateInHz, int channelConfig, int audioFormat)
Returns the minimum buffer size required for the successful creation of an AudioRecord
object, in byte units.
Note that this size doesn't guarantee a smooth recording under load, and higher values
should be chosen according to the expected frequency at which the AudioRecord instance
will be polled for new data.
See AudioRecord(int, int, int, int, int)
for more information on valid
configuration values.
Parameters | |
---|---|
sampleRateInHz |
int : the sample rate expressed in Hertz.
AudioFormat.SAMPLE_RATE_UNSPECIFIED is not permitted. |
channelConfig |
int : describes the configuration of the audio channels.
See AudioFormat.CHANNEL_IN_MONO and
AudioFormat.CHANNEL_IN_STEREO |
audioFormat |
int : the format in which the audio data is represented.
See AudioFormat.ENCODING_PCM_16BIT . |
Returns | |
---|---|
int |
ERROR_BAD_VALUE if the recording parameters are not supported by the
hardware, or an invalid parameter was passed,
or ERROR if the implementation was unable to query the hardware for its
input properties,
or the minimum buffer size expressed in bytes. |
See also:
getNotificationMarkerPosition
public int getNotificationMarkerPosition ()
Returns the notification marker position expressed in frames.
Returns | |
---|---|
int |
getPositionNotificationPeriod
public int getPositionNotificationPeriod ()
Returns the notification update period expressed in frames.
Returns | |
---|---|
int |
getPreferredDevice
public AudioDeviceInfo getPreferredDevice ()
Returns the selected input specified by setPreferredDevice(AudioDeviceInfo)
. Note that this
is not guarenteed to correspond to the actual device being used for recording.
Returns | |
---|---|
AudioDeviceInfo |
getRecordingState
public int getRecordingState ()
Returns the recording state of the AudioRecord instance.
Returns | |
---|---|
int |
See also:
getRoutedDevice
public AudioDeviceInfo getRoutedDevice ()
Returns an AudioDeviceInfo
identifying the current routing of this AudioRecord.
Note: The query is only valid if the AudioRecord is currently recording. If it is not,
getRoutedDevice()
will return null.
Returns | |
---|---|
AudioDeviceInfo |
getSampleRate
public int getSampleRate ()
Returns the configured audio sink sample rate in Hz.
The sink sample rate never changes after construction.
If the constructor had a specific sample rate, then the sink sample rate is that value.
If the constructor had AudioFormat.SAMPLE_RATE_UNSPECIFIED
,
then the sink sample rate is a route-dependent default value based on the source [sic].
Returns | |
---|---|
int |
getState
public int getState ()
Returns the state of the AudioRecord instance. This is useful after the AudioRecord instance has been created to check if it was initialized properly. This ensures that the appropriate hardware resources have been acquired.
Returns | |
---|---|
int |
See also:
getTimestamp
public int getTimestamp (AudioTimestamp outTimestamp, int timebase)
Poll for an AudioTimestamp
on demand.
The AudioTimestamp reflects the frame delivery information at the earliest point available in the capture pipeline.
Calling startRecording()
following a stop()
will reset
the frame count to 0.
Parameters | |
---|---|
outTimestamp |
AudioTimestamp : a caller provided non-null AudioTimestamp instance,
which is updated with the AudioRecord frame delivery information upon success. |
timebase |
int : one of
AudioTimestamp.TIMEBASE_BOOTTIME or
AudioTimestamp.TIMEBASE_MONOTONIC ,
used to select the clock for the AudioTimestamp time.
Value is AudioTimestamp.TIMEBASE_MONOTONIC , or AudioTimestamp.TIMEBASE_BOOTTIME |
Returns | |
---|---|
int |
SUCCESS if a timestamp is available,
or ERROR_INVALID_OPERATION if a timestamp not available. |
isPrivacySensitive
public boolean isPrivacySensitive ()
Returns whether this AudioRecord is marked as privacy sensitive or not.
See Builder.setPrivacySensitive(boolean)
Returns | |
---|---|
boolean |
true if privacy sensitive, false otherwise |
read
public int read (short[] audioData, int offsetInShorts, int sizeInShorts, int readMode)
Reads audio data from the audio hardware for recording into a short array.
The format specified in the AudioRecord constructor should be
AudioFormat.ENCODING_PCM_16BIT
to correspond to the data in the array.
Parameters | |
---|---|
audioData |
short : the array to which the recorded audio data is written.
This value cannot be null . |
offsetInShorts |
int : index in audioData from which the data is written expressed in shorts.
Must not be negative, or cause the data access to go out of bounds of the array. |
sizeInShorts |
int : the number of requested shorts.
Must not be negative, or cause the data access to go out of bounds of the array. |
readMode |
int : one of READ_BLOCKING , READ_NON_BLOCKING .
With READ_BLOCKING , the read will block until all the requested data
is read.
With READ_NON_BLOCKING , the read will return immediately after
reading as much audio data as possible without blocking.
Value is READ_BLOCKING , or READ_NON_BLOCKING |
Returns | |
---|---|
int |
zero or the positive number of shorts that were read, or one of the following
error codes. The number of shorts will be a multiple of the channel count not to exceed
sizeInShorts.
|
read
public int read (ByteBuffer audioBuffer, int sizeInBytes, int readMode)
Reads audio data from the audio hardware for recording into a direct buffer. If this buffer
is not a direct buffer, this method will always return 0.
Note that the value returned by Buffer.position()
on this buffer is
unchanged after a call to this method.
The representation of the data in the buffer will depend on the format specified in
the AudioRecord constructor, and will be native endian.
Parameters | |
---|---|
audioBuffer |
ByteBuffer : the direct buffer to which the recorded audio data is written.
Data is written to audioBuffer.position().
This value cannot be null . |
sizeInBytes |
int : the number of requested bytes. It is recommended but not enforced
that the number of bytes requested be a multiple of the frame size (sample size in
bytes multiplied by the channel count). |
readMode |
int : one of READ_BLOCKING , READ_NON_BLOCKING .
With READ_BLOCKING , the read will block until all the requested data
is read.
With READ_NON_BLOCKING , the read will return immediately after
reading as much audio data as possible without blocking.
Value is READ_BLOCKING , or READ_NON_BLOCKING |
Returns | |
---|---|
int |
zero or the positive number of bytes that were read, or one of the following
error codes. The number of bytes will not exceed sizeInBytes and will be truncated to be
a multiple of the frame size.
|
read
public int read (short[] audioData, int offsetInShorts, int sizeInShorts)
Reads audio data from the audio hardware for recording into a short array.
The format specified in the AudioRecord constructor should be
AudioFormat.ENCODING_PCM_16BIT
to correspond to the data in the array.
Parameters | |
---|---|
audioData |
short : the array to which the recorded audio data is written.
This value cannot be null . |
offsetInShorts |
int : index in audioData to which the data is written expressed in shorts.
Must not be negative, or cause the data access to go out of bounds of the array. |
sizeInShorts |
int : the number of requested shorts.
Must not be negative, or cause the data access to go out of bounds of the array. |
Returns | |
---|---|
int |
zero or the positive number of shorts that were read, or one of the following
error codes. The number of shorts will be a multiple of the channel count not to exceed
sizeInShorts.
|
read
public int read (float[] audioData, int offsetInFloats, int sizeInFloats, int readMode)
Reads audio data from the audio hardware for recording into a float array.
The format specified in the AudioRecord constructor should be
AudioFormat.ENCODING_PCM_FLOAT
to correspond to the data in the array.
Parameters | |
---|---|
audioData |
float : the array to which the recorded audio data is written.
This value cannot be null . |
offsetInFloats |
int : index in audioData from which the data is written.
Must not be negative, or cause the data access to go out of bounds of the array. |
sizeInFloats |
int : the number of requested floats.
Must not be negative, or cause the data access to go out of bounds of the array. |
readMode |
int : one of READ_BLOCKING , READ_NON_BLOCKING .
With READ_BLOCKING , the read will block until all the requested data
is read.
With READ_NON_BLOCKING , the read will return immediately after
reading as much audio data as possible without blocking.
Value is READ_BLOCKING , or READ_NON_BLOCKING |
Returns | |
---|---|
int |
zero or the positive number of floats that were read, or one of the following
error codes. The number of floats will be a multiple of the channel count not to exceed
sizeInFloats.
|
read
public int read (byte[] audioData, int offsetInBytes, int sizeInBytes, int readMode)
Reads audio data from the audio hardware for recording into a byte array.
The format specified in the AudioRecord constructor should be
AudioFormat.ENCODING_PCM_8BIT
to correspond to the data in the array.
The format can be AudioFormat.ENCODING_PCM_16BIT
, but this is deprecated.
Parameters | |
---|---|
audioData |
byte : the array to which the recorded audio data is written.
This value cannot be null . |
offsetInBytes |
int : index in audioData to which the data is written expressed in bytes.
Must not be negative, or cause the data access to go out of bounds of the array. |
sizeInBytes |
int : the number of requested bytes.
Must not be negative, or cause the data access to go out of bounds of the array. |
readMode |
int : one of READ_BLOCKING , READ_NON_BLOCKING .
With READ_BLOCKING , the read will block until all the requested data
is read.
With READ_NON_BLOCKING , the read will return immediately after
reading as much audio data as possible without blocking.
Value is READ_BLOCKING , or READ_NON_BLOCKING |
Returns | |
---|---|
int |
zero or the positive number of bytes that were read, or one of the following
error codes. The number of bytes will be a multiple of the frame size in bytes
not to exceed sizeInBytes.
|
read
public int read (ByteBuffer audioBuffer, int sizeInBytes)
Reads audio data from the audio hardware for recording into a direct buffer. If this buffer
is not a direct buffer, this method will always return 0.
Note that the value returned by Buffer.position()
on this buffer is
unchanged after a call to this method.
The representation of the data in the buffer will depend on the format specified in
the AudioRecord constructor, and will be native endian.
Parameters | |
---|---|
audioBuffer |
ByteBuffer : the direct buffer to which the recorded audio data is written.
Data is written to audioBuffer.position().
This value cannot be null . |
sizeInBytes |
int : the number of requested bytes. It is recommended but not enforced
that the number of bytes requested be a multiple of the frame size (sample size in
bytes multiplied by the channel count). |
Returns | |
---|---|
int |
zero or the positive number of bytes that were read, or one of the following
error codes. The number of bytes will not exceed sizeInBytes and will be truncated to be
a multiple of the frame size.
|
read
public int read (byte[] audioData, int offsetInBytes, int sizeInBytes)
Reads audio data from the audio hardware for recording into a byte array.
The format specified in the AudioRecord constructor should be
AudioFormat.ENCODING_PCM_8BIT
to correspond to the data in the array.
Parameters | |
---|---|
audioData |
byte : the array to which the recorded audio data is written.
This value cannot be null . |
offsetInBytes |
int : index in audioData from which the data is written expressed in bytes. |
sizeInBytes |
int : the number of requested bytes. |
Returns | |
---|---|
int |
zero or the positive number of bytes that were read, or one of the following
error codes. The number of bytes will not exceed sizeInBytes.
|
registerAudioRecordingCallback
public void registerAudioRecordingCallback (Executor executor, AudioManager.AudioRecordingCallback cb)
Register a callback to be notified of audio capture changes via a
AudioManager.AudioRecordingCallback
. A callback is received when the capture path
configuration changes (pre-processing, format, sampling rate...) or capture is
silenced/unsilenced by the system.
Parameters | |
---|---|
executor |
Executor : Executor to handle the callbacks.
This value cannot be null .
Callback and listener events are dispatched through this
Executor , providing an easy way to control which thread is
used. To dispatch events through the main thread of your
application, you can use
Context.getMainExecutor() .
Otherwise, provide an Executor that dispatches to an appropriate thread. |
cb |
AudioManager.AudioRecordingCallback : non-null callback to register |
release
public void release ()
Releases the native AudioRecord resources. The object can no longer be used and the reference should be set to null after a call to release()
removeOnRoutingChangedListener
public void removeOnRoutingChangedListener (AudioRecord.OnRoutingChangedListener listener)
This method was deprecated
in API level 24.
users should switch to the general purpose
AudioRouting.OnRoutingChangedListener
class instead.
Removes an OnRoutingChangedListener
which has been previously added
to receive rerouting notifications.
Parameters | |
---|---|
listener |
AudioRecord.OnRoutingChangedListener : The previously added OnRoutingChangedListener interface to remove. |
removeOnRoutingChangedListener
public void removeOnRoutingChangedListener (AudioRouting.OnRoutingChangedListener listener)
Removes an AudioRouting.OnRoutingChangedListener
which has been previously added
to receive rerouting notifications.
Parameters | |
---|---|
listener |
AudioRouting.OnRoutingChangedListener : The previously added AudioRouting.OnRoutingChangedListener interface
to remove. |
setLogSessionId
public void setLogSessionId (LogSessionId logSessionId)
Sets a LogSessionId
instance to this AudioRecord for metrics collection.
Parameters | |
---|---|
logSessionId |
LogSessionId : a LogSessionId instance which is used to
identify this object to the metrics service. Proper generated
Ids must be obtained from the Java metrics service and should
be considered opaque. Use
LogSessionId.LOG_SESSION_ID_NONE to remove the
logSessionId association.
This value cannot be null . |
Throws | |
---|---|
IllegalStateException |
if AudioRecord not initialized. |
setNotificationMarkerPosition
public int setNotificationMarkerPosition (int markerInFrames)
Sets the marker position at which the listener is called, if set with
setRecordPositionUpdateListener(android.media.AudioRecord.OnRecordPositionUpdateListener)
or
setRecordPositionUpdateListener(android.media.AudioRecord.OnRecordPositionUpdateListener, android.os.Handler)
.
Parameters | |
---|---|
markerInFrames |
int : marker position expressed in frames |
Returns | |
---|---|
int |
error code or success, see SUCCESS , ERROR_BAD_VALUE ,
ERROR_INVALID_OPERATION |
setPositionNotificationPeriod
public int setPositionNotificationPeriod (int periodInFrames)
Sets the period at which the listener is called, if set with
setRecordPositionUpdateListener(android.media.AudioRecord.OnRecordPositionUpdateListener)
or
setRecordPositionUpdateListener(android.media.AudioRecord.OnRecordPositionUpdateListener, android.os.Handler)
.
It is possible for notifications to be lost if the period is too small.
Parameters | |
---|---|
periodInFrames |
int : update period expressed in frames |
Returns | |
---|---|
int |
error code or success, see SUCCESS , ERROR_INVALID_OPERATION |
setPreferredDevice
public boolean setPreferredDevice (AudioDeviceInfo deviceInfo)
Specifies an audio device (via an AudioDeviceInfo
object) to route
the input to this AudioRecord.
Parameters | |
---|---|
deviceInfo |
AudioDeviceInfo : The AudioDeviceInfo specifying the audio source.
If deviceInfo is null, default routing is restored. |
Returns | |
---|---|
boolean |
true if successful, false if the specified AudioDeviceInfo is non-null and
does not correspond to a valid audio input device. |
setPreferredMicrophoneDirection
public boolean setPreferredMicrophoneDirection (int direction)
Specifies the logical microphone (for processing). Applications can use this to specify which side of the device to optimize capture from. Typically used in conjunction with the camera capturing video.
Returns | |
---|---|
boolean |
true if sucessful. |
setPreferredMicrophoneFieldDimension
public boolean setPreferredMicrophoneFieldDimension (float zoom)
Specifies the zoom factor (i.e. the field dimension) for the selected microphone (for processing). The selected microphone is determined by the use-case for the stream.
Parameters | |
---|---|
zoom |
float : the desired field dimension of microphone capture. Range is from -1 (wide angle),
though 0 (no zoom) to 1 (maximum zoom).
Value is between -1.0 and 1.0 inclusive |
Returns | |
---|---|
boolean |
true if sucessful. |
setRecordPositionUpdateListener
public void setRecordPositionUpdateListener (AudioRecord.OnRecordPositionUpdateListener listener)
Sets the listener the AudioRecord notifies when a previously set marker is reached or for each periodic record head position update.
setRecordPositionUpdateListener
public void setRecordPositionUpdateListener (AudioRecord.OnRecordPositionUpdateListener listener, Handler handler)
Sets the listener the AudioRecord notifies when a previously set marker is reached or for each periodic record head position update. Use this method to receive AudioRecord events in the Handler associated with another thread than the one in which you created the AudioRecord instance.
Parameters | |
---|---|
handler |
Handler : the Handler that will receive the event notification messages. |
startRecording
public void startRecording (MediaSyncEvent syncEvent)
Starts recording from the AudioRecord instance when the specified synchronization event occurs on the specified audio session.
Parameters | |
---|---|
syncEvent |
MediaSyncEvent : event that triggers the capture. |
Throws | |
---|---|
|
java.lang.IllegalStateException |
IllegalStateException |
See also:
startRecording
public void startRecording ()
Starts recording from the AudioRecord instance.
Throws | |
---|---|
|
java.lang.IllegalStateException |
IllegalStateException |
stop
public void stop ()
Stops recording.
Throws | |
---|---|
|
java.lang.IllegalStateException |
IllegalStateException |
unregisterAudioRecordingCallback
public void unregisterAudioRecordingCallback (AudioManager.AudioRecordingCallback cb)
Unregister an audio recording callback previously registered with
registerAudioRecordingCallback(java.util.concurrent.Executor, android.media.AudioManager.AudioRecordingCallback)
.
Parameters | |
---|---|
cb |
AudioManager.AudioRecordingCallback : non-null callback to unregister |
Protected methods
finalize
protected void finalize ()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
A subclass overrides the finalize
method to dispose of
system resources or to perform other cleanup.
The general contract of finalize
is that it is invoked
if and when the Java virtual
machine has determined that there is no longer any
means by which this object can be accessed by any thread that has
not yet died, except as a result of an action taken by the
finalization of some other object or class which is ready to be
finalized. The finalize
method may take any action, including
making this object available again to other threads; the usual purpose
of finalize
, however, is to perform cleanup actions before
the object is irrevocably discarded. For example, the finalize method
for an object that represents an input/output connection might perform
explicit I/O transactions to break the connection before the object is
permanently discarded.
The finalize
method of class Object
performs no
special action; it simply returns normally. Subclasses of
Object
may override this definition.
The Java programming language does not guarantee which thread will
invoke the finalize
method for any given object. It is
guaranteed, however, that the thread that invokes finalize will not
be holding any user-visible synchronization locks when finalize is
invoked. If an uncaught exception is thrown by the finalize method,
the exception is ignored and finalization of that object terminates.
After the finalize
method has been invoked for an object, no
further action is taken until the Java virtual machine has again
determined that there is no longer any means by which this object can
be accessed by any thread that has not yet died, including possible
actions by other objects or classes which are ready to be finalized,
at which point the object may be discarded.
The finalize
method is never invoked more than once by a Java
virtual machine for any given object.
Any exception thrown by the finalize
method causes
the finalization of this object to be halted, but is otherwise
ignored.
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Last updated 2024-12-18 UTC.