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Android example source code file (AudioTrack.java)
This example Android source code file (AudioTrack.java) is included in the DevDaily.com
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Warehouse" project. The intent of this project is to help you "Learn
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The AudioTrack.java Android example source code
/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.media;
import java.lang.ref.WeakReference;
import java.lang.IllegalArgumentException;
import java.lang.IllegalStateException;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.media.AudioManager;
import android.util.Log;
/**
* The AudioTrack class manages and plays a single audio resource for Java applications.
* It allows to stream PCM audio buffers to the audio hardware for playback. This is
* achieved by "pushing" the data to the AudioTrack object using one of the
* {@link #write(byte[], int, int)} and {@link #write(short[], int, int)} methods.
*
* <p>An AudioTrack instance can operate under two modes: static or streaming.
* In Streaming mode, the application writes a continuous stream of data to the AudioTrack, using
* one of the write() methods. These are blocking and return when the data has been transferred
* from the Java layer to the native layer and queued for playback. The streaming mode
* is most useful when playing blocks of audio data that for instance are:
* <ul>
* <li>too big to fit in memory because of the duration of the sound to play,
* <li>too big to fit in memory because of the characteristics of the audio data
* (high sampling rate, bits per sample ...)</li>
* <li>received or generated while previously queued audio is playing.
* </ul>
* The static mode is to be chosen when dealing with short sounds that fit in memory and
* that need to be played with the smallest latency possible. AudioTrack instances in static mode
* can play the sound without the need to transfer the audio data from Java to native layer
* each time the sound is to be played. The static mode will therefore be preferred for UI and
* game sounds that are played often, and with the smallest overhead possible.
*
* <p>Upon creation, an AudioTrack object initializes its associated audio buffer.
* The size of this buffer, specified during the construction, determines how long an AudioTrack
* can play before running out of data.<br>
* For an AudioTrack using the static mode, this size is the maximum size of the sound that can
* be played from it.<br>
* For the streaming mode, data will be written to the hardware in chunks of
* sizes inferior to the total buffer size.
*/
public class AudioTrack
{
//---------------------------------------------------------
// Constants
//--------------------
/** Minimum value for a channel volume */
private static final float VOLUME_MIN = 0.0f;
/** Maximum value for a channel volume */
private static final float VOLUME_MAX = 1.0f;
/** indicates AudioTrack state is stopped */
public static final int PLAYSTATE_STOPPED = 1; // matches SL_PLAYSTATE_STOPPED
/** indicates AudioTrack state is paused */
public static final int PLAYSTATE_PAUSED = 2; // matches SL_PLAYSTATE_PAUSED
/** indicates AudioTrack state is playing */
public static final int PLAYSTATE_PLAYING = 3; // matches SL_PLAYSTATE_PLAYING
/**
* Creation mode where audio data is transferred from Java to the native layer
* only once before the audio starts playing.
*/
public static final int MODE_STATIC = 0;
/**
* Creation mode where audio data is streamed from Java to the native layer
* as the audio is playing.
*/
public static final int MODE_STREAM = 1;
/**
* State of an AudioTrack that was not successfully initialized upon creation.
*/
public static final int STATE_UNINITIALIZED = 0;
/**
* State of an AudioTrack that is ready to be used.
*/
public static final int STATE_INITIALIZED = 1;
/**
* State of a successfully initialized AudioTrack that uses static data,
* but that hasn't received that data yet.
*/
public static final int STATE_NO_STATIC_DATA = 2;
// Error codes:
// to keep in sync with frameworks/base/core/jni/android_media_AudioTrack.cpp
/**
* Denotes a successful operation.
*/
public static final int SUCCESS = 0;
/**
* Denotes a generic operation failure.
*/
public static final int ERROR = -1;
/**
* Denotes a failure due to the use of an invalid value.
*/
public static final int ERROR_BAD_VALUE = -2;
/**
* Denotes a failure due to the improper use of a method.
*/
public static final int ERROR_INVALID_OPERATION = -3;
private static final int ERROR_NATIVESETUP_AUDIOSYSTEM = -16;
private static final int ERROR_NATIVESETUP_INVALIDCHANNELMASK = -17;
private static final int ERROR_NATIVESETUP_INVALIDFORMAT = -18;
private static final int ERROR_NATIVESETUP_INVALIDSTREAMTYPE = -19;
private static final int ERROR_NATIVESETUP_NATIVEINITFAILED = -20;
// Events:
// to keep in sync with frameworks/base/include/media/AudioTrack.h
/**
* Event id denotes when playback head has reached a previously set marker.
*/
private static final int NATIVE_EVENT_MARKER = 3;
/**
* Event id denotes when previously set update period has elapsed during playback.
*/
private static final int NATIVE_EVENT_NEW_POS = 4;
private final static String TAG = "AudioTrack-Java";
//--------------------------------------------------------------------------
// Member variables
//--------------------
/**
* Indicates the state of the AudioTrack instance.
*/
private int mState = STATE_UNINITIALIZED;
/**
* Indicates the play state of the AudioTrack instance.
*/
private int mPlayState = PLAYSTATE_STOPPED;
/**
* Lock to make sure mPlayState updates are reflecting the actual state of the object.
*/
private final Object mPlayStateLock = new Object();
/**
* The listener the AudioTrack notifies when the playback position reaches a marker
* or for periodic updates during the progression of the playback head.
* @see #setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener)
*/
private OnPlaybackPositionUpdateListener mPositionListener = null;
/**
* Lock to protect event listener updates against event notifications.
*/
private final Object mPositionListenerLock = new Object();
/**
* Size of the native audio buffer.
*/
private int mNativeBufferSizeInBytes = 0;
/**
* Handler for marker events coming from the native code.
*/
private NativeEventHandlerDelegate mEventHandlerDelegate = null;
/**
* Looper associated with the thread that creates the AudioTrack instance.
*/
private Looper mInitializationLooper = null;
/**
* The audio data sampling rate in Hz.
*/
private int mSampleRate = 22050;
/**
* The number of audio output channels (1 is mono, 2 is stereo).
*/
private int mChannelCount = 1;
/**
* The audio channel mask.
*/
private int mChannels = AudioFormat.CHANNEL_OUT_MONO;
/**
* The type of the audio stream to play. See
* {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM},
* {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC} and
* {@link AudioManager#STREAM_ALARM}
*/
private int mStreamType = AudioManager.STREAM_MUSIC;
/**
* The way audio is consumed by the hardware, streaming or static.
*/
private int mDataLoadMode = MODE_STREAM;
/**
* The current audio channel configuration.
*/
private int mChannelConfiguration = AudioFormat.CHANNEL_OUT_MONO;
/**
* The encoding of the audio samples.
* @see AudioFormat#ENCODING_PCM_8BIT
* @see AudioFormat#ENCODING_PCM_16BIT
*/
private int mAudioFormat = AudioFormat.ENCODING_PCM_16BIT;
//--------------------------------
// Used exclusively by native code
//--------------------
/**
* Accessed by native methods: provides access to C++ AudioTrack object.
*/
@SuppressWarnings("unused")
private int mNativeTrackInJavaObj;
/**
* Accessed by native methods: provides access to the JNI data (i.e. resources used by
* the native AudioTrack object, but not stored in it).
*/
@SuppressWarnings("unused")
private int mJniData;
//--------------------------------------------------------------------------
// Constructor, Finalize
//--------------------
/**
* Class constructor.
* @param streamType the type of the audio stream. See
* {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM},
* {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC} and
* {@link AudioManager#STREAM_ALARM}
* @param sampleRateInHz the sample rate expressed in Hertz. Examples of rates are (but
* not limited to) 44100, 22050 and 11025.
* @param channelConfig describes the configuration of the audio channels.
* See {@link AudioFormat#CHANNEL_OUT_MONO} and
* {@link AudioFormat#CHANNEL_OUT_STEREO}
* @param audioFormat the format in which the audio data is represented.
* See {@link AudioFormat#ENCODING_PCM_16BIT} and
* {@link AudioFormat#ENCODING_PCM_8BIT}
* @param bufferSizeInBytes the total size (in bytes) of the buffer where audio data is read
* from for playback. If using the AudioTrack in streaming mode, you can write data into
* this buffer in smaller chunks than this size. If using the AudioTrack in static mode,
* this is the maximum size of the sound that will be played for this instance.
* See {@link #getMinBufferSize(int, int, int)} to determine the minimum required buffer size
* for the successful creation of an AudioTrack instance in streaming mode. Using values
* smaller than getMinBufferSize() will result in an initialization failure.
* @param mode streaming or static buffer. See {@link #MODE_STATIC} and {@link #MODE_STREAM}
* @throws java.lang.IllegalArgumentException
*/
public AudioTrack(int streamType, int sampleRateInHz, int channelConfig, int audioFormat,
int bufferSizeInBytes, int mode)
throws IllegalArgumentException {
mState = STATE_UNINITIALIZED;
// remember which looper is associated with the AudioTrack instanciation
if ((mInitializationLooper = Looper.myLooper()) == null) {
mInitializationLooper = Looper.getMainLooper();
}
audioParamCheck(streamType, sampleRateInHz, channelConfig, audioFormat, mode);
audioBuffSizeCheck(bufferSizeInBytes);
// native initialization
int initResult = native_setup(new WeakReference<AudioTrack>(this),
mStreamType, mSampleRate, mChannels, mAudioFormat,
mNativeBufferSizeInBytes, mDataLoadMode);
if (initResult != SUCCESS) {
loge("Error code "+initResult+" when initializing AudioTrack.");
return; // with mState == STATE_UNINITIALIZED
}
if (mDataLoadMode == MODE_STATIC) {
mState = STATE_NO_STATIC_DATA;
} else {
mState = STATE_INITIALIZED;
}
}
// Convenience method for the constructor's parameter checks.
// This is where constructor IllegalArgumentException-s are thrown
// postconditions:
// mStreamType is valid
// mChannelCount is valid
// mChannels is valid
// mAudioFormat is valid
// mSampleRate is valid
// mDataLoadMode is valid
private void audioParamCheck(int streamType, int sampleRateInHz,
int channelConfig, int audioFormat, int mode) {
//--------------
// stream type
if( (streamType != AudioManager.STREAM_ALARM) && (streamType != AudioManager.STREAM_MUSIC)
&& (streamType != AudioManager.STREAM_RING) && (streamType != AudioManager.STREAM_SYSTEM)
&& (streamType != AudioManager.STREAM_VOICE_CALL)
&& (streamType != AudioManager.STREAM_NOTIFICATION)
&& (streamType != AudioManager.STREAM_BLUETOOTH_SCO)
&& (streamType != AudioManager.STREAM_DTMF)) {
throw (new IllegalArgumentException("Invalid stream type."));
} else {
mStreamType = streamType;
}
//--------------
// sample rate
if ( (sampleRateInHz < 4000) || (sampleRateInHz > 48000) ) {
throw (new IllegalArgumentException(sampleRateInHz
+ "Hz is not a supported sample rate."));
} else {
mSampleRate = sampleRateInHz;
}
//--------------
// channel config
mChannelConfiguration = channelConfig;
switch (channelConfig) {
case AudioFormat.CHANNEL_OUT_DEFAULT: //AudioFormat.CHANNEL_CONFIGURATION_DEFAULT
case AudioFormat.CHANNEL_OUT_MONO:
case AudioFormat.CHANNEL_CONFIGURATION_MONO:
mChannelCount = 1;
mChannels = AudioFormat.CHANNEL_OUT_MONO;
break;
case AudioFormat.CHANNEL_OUT_STEREO:
case AudioFormat.CHANNEL_CONFIGURATION_STEREO:
mChannelCount = 2;
mChannels = AudioFormat.CHANNEL_OUT_STEREO;
break;
default:
mChannelCount = 0;
mChannels = AudioFormat.CHANNEL_INVALID;
mChannelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_INVALID;
throw(new IllegalArgumentException("Unsupported channel configuration."));
}
//--------------
// audio format
switch (audioFormat) {
case AudioFormat.ENCODING_DEFAULT:
mAudioFormat = AudioFormat.ENCODING_PCM_16BIT;
break;
case AudioFormat.ENCODING_PCM_16BIT:
case AudioFormat.ENCODING_PCM_8BIT:
mAudioFormat = audioFormat;
break;
default:
mAudioFormat = AudioFormat.ENCODING_INVALID;
throw(new IllegalArgumentException("Unsupported sample encoding."
+ " Should be ENCODING_PCM_8BIT or ENCODING_PCM_16BIT."));
}
//--------------
// audio load mode
if ( (mode != MODE_STREAM) && (mode != MODE_STATIC) ) {
throw(new IllegalArgumentException("Invalid mode."));
} else {
mDataLoadMode = mode;
}
}
// Convenience method for the contructor's audio buffer size check.
// preconditions:
// mChannelCount is valid
// mAudioFormat is valid
// postcondition:
// mNativeBufferSizeInBytes is valid (multiple of frame size, positive)
private void audioBuffSizeCheck(int audioBufferSize) {
// NB: this section is only valid with PCM data.
// To update when supporting compressed formats
int frameSizeInBytes = mChannelCount
* (mAudioFormat == AudioFormat.ENCODING_PCM_8BIT ? 1 : 2);
if ((audioBufferSize % frameSizeInBytes != 0) || (audioBufferSize < 1)) {
throw (new IllegalArgumentException("Invalid audio buffer size."));
}
mNativeBufferSizeInBytes = audioBufferSize;
}
/**
* Releases the native AudioTrack resources.
*/
public void release() {
// even though native_release() stops the native AudioTrack, we need to stop
// AudioTrack subclasses too.
try {
stop();
} catch(IllegalStateException ise) {
// don't raise an exception, we're releasing the resources.
}
native_release();
mState = STATE_UNINITIALIZED;
}
@Override
protected void finalize() {
native_finalize();
}
//--------------------------------------------------------------------------
// Getters
//--------------------
/**
* Returns the minimum valid volume value. Volume values set under this one will
* be clamped at this value.
* @return the minimum volume expressed as a linear attenuation.
*/
static public float getMinVolume() {
return AudioTrack.VOLUME_MIN;
}
/**
* Returns the maximum valid volume value. Volume values set above this one will
* be clamped at this value.
* @return the maximum volume expressed as a linear attenuation.
*/
static public float getMaxVolume() {
return AudioTrack.VOLUME_MAX;
}
/**
* Returns the configured audio data sample rate in Hz
*/
public int getSampleRate() {
return mSampleRate;
}
/**
* Returns the current playback rate in Hz.
*/
public int getPlaybackRate() {
return native_get_playback_rate();
}
/**
* Returns the configured audio data format. See {@link AudioFormat#ENCODING_PCM_16BIT}
* and {@link AudioFormat#ENCODING_PCM_8BIT}.
*/
public int getAudioFormat() {
return mAudioFormat;
}
/**
* Returns the type of audio stream this AudioTrack is configured for.
* Compare the result against {@link AudioManager#STREAM_VOICE_CALL},
* {@link AudioManager#STREAM_SYSTEM}, {@link AudioManager#STREAM_RING},
* {@link AudioManager#STREAM_MUSIC} or {@link AudioManager#STREAM_ALARM}
*/
public int getStreamType() {
return mStreamType;
}
/**
* Returns the configured channel configuration.
* See {@link AudioFormat#CHANNEL_OUT_MONO}
* and {@link AudioFormat#CHANNEL_OUT_STEREO}.
*/
public int getChannelConfiguration() {
return mChannelConfiguration;
}
/**
* Returns the configured number of channels.
*/
public int getChannelCount() {
return mChannelCount;
}
/**
* Returns the state of the AudioTrack instance. This is useful after the
* AudioTrack instance has been created to check if it was initialized
* properly. This ensures that the appropriate hardware resources have been
* acquired.
* @see #STATE_INITIALIZED
* @see #STATE_NO_STATIC_DATA
* @see #STATE_UNINITIALIZED
*/
public int getState() {
return mState;
}
/**
* Returns the playback state of the AudioTrack instance.
* @see #PLAYSTATE_STOPPED
* @see #PLAYSTATE_PAUSED
* @see #PLAYSTATE_PLAYING
*/
public int getPlayState() {
return mPlayState;
}
/**
* Returns the native frame count used by the hardware.
*/
protected int getNativeFrameCount() {
return native_get_native_frame_count();
}
/**
* Returns marker position expressed in frames.
*/
public int getNotificationMarkerPosition() {
return native_get_marker_pos();
}
/**
* Returns the notification update period expressed in frames.
*/
public int getPositionNotificationPeriod() {
return native_get_pos_update_period();
}
/**
* Returns the playback head position expressed in frames
*/
public int getPlaybackHeadPosition() {
return native_get_position();
}
/**
* Returns the hardware output sample rate
*/
static public int getNativeOutputSampleRate(int streamType) {
return native_get_output_sample_rate(streamType);
}
/**
* Returns the minimum buffer size required for the successful creation of an AudioTrack
* object to be created in the {@link #MODE_STREAM} mode. Note that this size doesn't
* guarantee a smooth playback under load, and higher values should be chosen according to
* the expected frequency at which the buffer will be refilled with additional data to play.
* @param sampleRateInHz the sample rate expressed in Hertz.
* @param channelConfig describes the configuration of the audio channels.
* See {@link AudioFormat#CHANNEL_OUT_MONO} and
* {@link AudioFormat#CHANNEL_OUT_STEREO}
* @param audioFormat the format in which the audio data is represented.
* See {@link AudioFormat#ENCODING_PCM_16BIT} and
* {@link AudioFormat#ENCODING_PCM_8BIT}
* @return {@link #ERROR_BAD_VALUE} if an invalid parameter was passed,
* or {@link #ERROR} if the implementation was unable to query the hardware for its output
* properties,
* or the minimum buffer size expressed in bytes.
*/
static public int getMinBufferSize(int sampleRateInHz, int channelConfig, int audioFormat) {
int channelCount = 0;
switch(channelConfig) {
case AudioFormat.CHANNEL_OUT_MONO:
case AudioFormat.CHANNEL_CONFIGURATION_MONO:
channelCount = 1;
break;
case AudioFormat.CHANNEL_OUT_STEREO:
case AudioFormat.CHANNEL_CONFIGURATION_STEREO:
channelCount = 2;
break;
default:
loge("getMinBufferSize(): Invalid channel configuration.");
return AudioTrack.ERROR_BAD_VALUE;
}
if ((audioFormat != AudioFormat.ENCODING_PCM_16BIT)
&& (audioFormat != AudioFormat.ENCODING_PCM_8BIT)) {
loge("getMinBufferSize(): Invalid audio format.");
return AudioTrack.ERROR_BAD_VALUE;
}
if ( (sampleRateInHz < 4000) || (sampleRateInHz > 48000) ) {
loge("getMinBufferSize(): " + sampleRateInHz +"Hz is not a supported sample rate.");
return AudioTrack.ERROR_BAD_VALUE;
}
int size = native_get_min_buff_size(sampleRateInHz, channelCount, audioFormat);
if ((size == -1) || (size == 0)) {
loge("getMinBufferSize(): error querying hardware");
return AudioTrack.ERROR;
}
else {
return size;
}
}
//--------------------------------------------------------------------------
// Initialization / configuration
//--------------------
/**
* Sets the listener the AudioTrack notifies when a previously set marker is reached or
* for each periodic playback head position update.
* Notifications will be received in the same thread as the one in which the AudioTrack
* instance was created.
* @param listener
*/
public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener) {
setPlaybackPositionUpdateListener(listener, null);
}
/**
* Sets the listener the AudioTrack notifies when a previously set marker is reached or
* for each periodic playback head position update.
* Use this method to receive AudioTrack events in the Handler associated with another
* thread than the one in which you created the AudioTrack instance.
* @param listener
* @param handler the Handler that will receive the event notification messages.
*/
public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener,
Handler handler) {
synchronized (mPositionListenerLock) {
mPositionListener = listener;
}
if (listener != null) {
mEventHandlerDelegate = new NativeEventHandlerDelegate(this, handler);
}
}
/**
* Sets the specified left/right output volume values on the AudioTrack. Values are clamped
* to the ({@link #getMinVolume()}, {@link #getMaxVolume()}) interval if outside this range.
* @param leftVolume output attenuation for the left channel. A value of 0.0f is silence,
* a value of 1.0f is no attenuation.
* @param rightVolume output attenuation for the right channel
* @return error code or success, see {@link #SUCCESS},
* {@link #ERROR_INVALID_OPERATION}
*/
public int setStereoVolume(float leftVolume, float rightVolume) {
if (mState != STATE_INITIALIZED) {
return ERROR_INVALID_OPERATION;
}
// clamp the volumes
if (leftVolume < getMinVolume()) {
leftVolume = getMinVolume();
}
if (leftVolume > getMaxVolume()) {
leftVolume = getMaxVolume();
}
if (rightVolume < getMinVolume()) {
rightVolume = getMinVolume();
}
if (rightVolume > getMaxVolume()) {
rightVolume = getMaxVolume();
}
native_setVolume(leftVolume, rightVolume);
return SUCCESS;
}
/**
* Sets the playback sample rate for this track. This sets the sampling rate at which
* the audio data will be consumed and played back, not the original sampling rate of the
* content. Setting it to half the sample rate of the content will cause the playback to
* last twice as long, but will also result in a negative pitch shift.
* The valid sample rate range if from 1Hz to twice the value returned by
* {@link #getNativeOutputSampleRate(int)}.
* @param sampleRateInHz the sample rate expressed in Hz
* @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE},
* {@link #ERROR_INVALID_OPERATION}
*/
public int setPlaybackRate(int sampleRateInHz) {
if (mState != STATE_INITIALIZED) {
return ERROR_INVALID_OPERATION;
}
if (sampleRateInHz <= 0) {
return ERROR_BAD_VALUE;
}
return native_set_playback_rate(sampleRateInHz);
}
/**
* Sets the position of the notification marker.
* @param markerInFrames marker in frames
* @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE},
* {@link #ERROR_INVALID_OPERATION}
*/
public int setNotificationMarkerPosition(int markerInFrames) {
if (mState != STATE_INITIALIZED) {
return ERROR_INVALID_OPERATION;
}
return native_set_marker_pos(markerInFrames);
}
/**
* Sets the period for the periodic notification event.
* @param periodInFrames update period expressed in frames
* @return error code or success, see {@link #SUCCESS}, {@link #ERROR_INVALID_OPERATION}
*/
public int setPositionNotificationPeriod(int periodInFrames) {
if (mState != STATE_INITIALIZED) {
return ERROR_INVALID_OPERATION;
}
return native_set_pos_update_period(periodInFrames);
}
/**
* Sets the playback head position. The track must be stopped for the position to be changed.
* @param positionInFrames playback head position expressed in frames
* @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE},
* {@link #ERROR_INVALID_OPERATION}
*/
public int setPlaybackHeadPosition(int positionInFrames) {
synchronized(mPlayStateLock) {
if ((mPlayState == PLAYSTATE_STOPPED) || (mPlayState == PLAYSTATE_PAUSED)) {
return native_set_position(positionInFrames);
} else {
return ERROR_INVALID_OPERATION;
}
}
}
/**
* Sets the loop points and the loop count. The loop can be infinite.
* @param startInFrames loop start marker expressed in frames
* @param endInFrames loop end marker expressed in frames
* @param loopCount the number of times the loop is looped.
* A value of -1 means infinite looping.
* @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE},
* {@link #ERROR_INVALID_OPERATION}
*/
public int setLoopPoints(int startInFrames, int endInFrames, int loopCount) {
if (mDataLoadMode == MODE_STREAM) {
return ERROR_INVALID_OPERATION;
}
return native_set_loop(startInFrames, endInFrames, loopCount);
}
/**
* Sets the initialization state of the instance. To be used in an AudioTrack subclass
* constructor to set a subclass-specific post-initialization state.
* @param state the state of the AudioTrack instance
*/
protected void setState(int state) {
mState = state;
}
//---------------------------------------------------------
// Transport control methods
//--------------------
/**
* Starts playing an AudioTrack.
* @throws IllegalStateException
*/
public void play()
throws IllegalStateException {
if (mState != STATE_INITIALIZED) {
throw(new IllegalStateException("play() called on uninitialized AudioTrack."));
}
synchronized(mPlayStateLock) {
native_start();
mPlayState = PLAYSTATE_PLAYING;
}
}
/**
* Stops playing the audio data.
* @throws IllegalStateException
*/
public void stop()
throws IllegalStateException {
if (mState != STATE_INITIALIZED) {
throw(new IllegalStateException("stop() called on uninitialized AudioTrack."));
}
// stop playing
synchronized(mPlayStateLock) {
native_stop();
mPlayState = PLAYSTATE_STOPPED;
}
}
/**
* Pauses the playback of the audio data.
* @throws IllegalStateException
*/
public void pause()
throws IllegalStateException {
if (mState != STATE_INITIALIZED) {
throw(new IllegalStateException("pause() called on uninitialized AudioTrack."));
}
//logd("pause()");
// pause playback
synchronized(mPlayStateLock) {
native_pause();
mPlayState = PLAYSTATE_PAUSED;
}
}
//---------------------------------------------------------
// Audio data supply
//--------------------
/**
* Flushes the audio data currently queued for playback.
*/
public void flush() {
if (mState == STATE_INITIALIZED) {
// flush the data in native layer
native_flush();
}
}
/**
* Writes the audio data to the audio hardware for playback.
* @param audioData the array that holds the data to play.
* @param offsetInBytes the offset expressed in bytes in audioData where the data to play
* starts.
* @param sizeInBytes the number of bytes to read in audioData after the offset.
* @return the number of bytes that were written or {@link #ERROR_INVALID_OPERATION}
* if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if
* the parameters don't resolve to valid data and indexes.
*/
public int write(byte[] audioData,int offsetInBytes, int sizeInBytes) {
if ((mDataLoadMode == MODE_STATIC)
&& (mState == STATE_NO_STATIC_DATA)
&& (sizeInBytes > 0)) {
mState = STATE_INITIALIZED;
}
if (mState != STATE_INITIALIZED) {
return ERROR_INVALID_OPERATION;
}
if ( (audioData == null) || (offsetInBytes < 0 ) || (sizeInBytes < 0)
|| (offsetInBytes + sizeInBytes > audioData.length)) {
return ERROR_BAD_VALUE;
}
return native_write_byte(audioData, offsetInBytes, sizeInBytes, mAudioFormat);
}
/**
* Writes the audio data to the audio hardware for playback.
* @param audioData the array that holds the data to play.
* @param offsetInShorts the offset expressed in shorts in audioData where the data to play
* starts.
* @param sizeInShorts the number of bytes to read in audioData after the offset.
* @return the number of shorts that were written or {@link #ERROR_INVALID_OPERATION}
* if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if
* the parameters don't resolve to valid data and indexes.
*/
public int write(short[] audioData, int offsetInShorts, int sizeInShorts) {
if ((mDataLoadMode == MODE_STATIC)
&& (mState == STATE_NO_STATIC_DATA)
&& (sizeInShorts > 0)) {
mState = STATE_INITIALIZED;
}
if (mState != STATE_INITIALIZED) {
return ERROR_INVALID_OPERATION;
}
if ( (audioData == null) || (offsetInShorts < 0 ) || (sizeInShorts < 0)
|| (offsetInShorts + sizeInShorts > audioData.length)) {
return ERROR_BAD_VALUE;
}
return native_write_short(audioData, offsetInShorts, sizeInShorts, mAudioFormat);
}
/**
* Notifies the native resource to reuse the audio data already loaded in the native
* layer. This call is only valid with AudioTrack instances that don't use the streaming
* model.
* @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE},
* {@link #ERROR_INVALID_OPERATION}
*/
public int reloadStaticData() {
if (mDataLoadMode == MODE_STREAM) {
return ERROR_INVALID_OPERATION;
}
return native_reload_static();
}
//---------------------------------------------------------
// Interface definitions
//--------------------
/**
* Interface definition for a callback to be invoked when the playback head position of
* an AudioTrack has reached a notification marker or has increased by a certain period.
*/
public interface OnPlaybackPositionUpdateListener {
/**
* Called on the listener to notify it that the previously set marker has been reached
* by the playback head.
*/
void onMarkerReached(AudioTrack track);
/**
* Called on the listener to periodically notify it that the playback head has reached
* a multiple of the notification period.
*/
void onPeriodicNotification(AudioTrack track);
}
//---------------------------------------------------------
// Inner classes
//--------------------
/**
* Helper class to handle the forwarding of native events to the appropriate listener
* (potentially) handled in a different thread
*/
private class NativeEventHandlerDelegate {
private final AudioTrack mAudioTrack;
private final Handler mHandler;
NativeEventHandlerDelegate(AudioTrack track, Handler handler) {
mAudioTrack = track;
// find the looper for our new event handler
Looper looper;
if (handler != null) {
looper = handler.getLooper();
} else {
// no given handler, use the looper the AudioTrack was created in
looper = mInitializationLooper;
}
// construct the event handler with this looper
if (looper != null) {
// implement the event handler delegate
mHandler = new Handler(looper) {
@Override
public void handleMessage(Message msg) {
if (mAudioTrack == null) {
return;
}
OnPlaybackPositionUpdateListener listener = null;
synchronized (mPositionListenerLock) {
listener = mAudioTrack.mPositionListener;
}
switch(msg.what) {
case NATIVE_EVENT_MARKER:
if (listener != null) {
listener.onMarkerReached(mAudioTrack);
}
break;
case NATIVE_EVENT_NEW_POS:
if (listener != null) {
listener.onPeriodicNotification(mAudioTrack);
}
break;
default:
Log.e(TAG, "[ android.media.AudioTrack.NativeEventHandler ] " +
"Unknown event type: " + msg.what);
break;
}
}
};
} else {
mHandler = null;
}
}
Handler getHandler() {
return mHandler;
}
}
//---------------------------------------------------------
// Java methods called from the native side
//--------------------
@SuppressWarnings("unused")
private static void postEventFromNative(Object audiotrack_ref,
int what, int arg1, int arg2, Object obj) {
//logd("Event posted from the native side: event="+ what + " args="+ arg1+" "+arg2);
AudioTrack track = (AudioTrack)((WeakReference)audiotrack_ref).get();
if (track == null) {
return;
}
if (track.mEventHandlerDelegate != null) {
Message m =
track.mEventHandlerDelegate.getHandler().obtainMessage(what, arg1, arg2, obj);
track.mEventHandlerDelegate.getHandler().sendMessage(m);
}
}
//---------------------------------------------------------
// Native methods called from the Java side
//--------------------
private native final int native_setup(Object audiotrack_this,
int streamType, int sampleRate, int nbChannels, int audioFormat,
int buffSizeInBytes, int mode);
private native final void native_finalize();
private native final void native_release();
private native final void native_start();
private native final void native_stop();
private native final void native_pause();
private native final void native_flush();
private native final int native_write_byte(byte[] audioData,
int offsetInBytes, int sizeInBytes, int format);
private native final int native_write_short(short[] audioData,
int offsetInShorts, int sizeInShorts, int format);
private native final int native_reload_static();
private native final int native_get_native_frame_count();
private native final void native_setVolume(float leftVolume, float rightVolume);
private native final int native_set_playback_rate(int sampleRateInHz);
private native final int native_get_playback_rate();
private native final int native_set_marker_pos(int marker);
private native final int native_get_marker_pos();
private native final int native_set_pos_update_period(int updatePeriod);
private native final int native_get_pos_update_period();
private native final int native_set_position(int position);
private native final int native_get_position();
private native final int native_set_loop(int start, int end, int loopCount);
static private native final int native_get_output_sample_rate(int streamType);
static private native final int native_get_min_buff_size(
int sampleRateInHz, int channelConfig, int audioFormat);
//---------------------------------------------------------
// Utility methods
//------------------
private static void logd(String msg) {
Log.d(TAG, "[ android.media.AudioTrack ] " + msg);
}
private static void loge(String msg) {
Log.e(TAG, "[ android.media.AudioTrack ] " + msg);
}
}
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