sdk/android/api/org/webrtc/audio/JavaAudioDeviceModule.java - src - Git at Google

 /*
  *  Copyright 2018 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */

 package org.webrtc.audio;

 import android.content.Context;
 import android.media.AudioAttributes;
 import android.media.AudioDeviceInfo;
 import android.media.AudioManager;
 import android.os.Build;
 import androidx.annotation.RequiresApi;
 import java.util.concurrent.ScheduledExecutorService;
 import org.webrtc.JniCommon;
 import org.webrtc.Logging;

 /**
  * AudioDeviceModule implemented using android.media.AudioRecord as input and
  * android.media.AudioTrack as output.
  */
 public class JavaAudioDeviceModule implements AudioDeviceModule {
   private static final String TAG = "JavaAudioDeviceModule";

   public static Builder builder(Context context) {
     return new Builder(context);
   }

   public static class Builder {
     private final Context context;
     private ScheduledExecutorService scheduler;
     private final AudioManager audioManager;
     private int inputSampleRate;
     private int outputSampleRate;
     private int audioSource = WebRtcAudioRecord.DEFAULT_AUDIO_SOURCE;
     private int audioFormat = WebRtcAudioRecord.DEFAULT_AUDIO_FORMAT;
     private AudioTrackErrorCallback audioTrackErrorCallback;
     private AudioRecordErrorCallback audioRecordErrorCallback;
     private SamplesReadyCallback samplesReadyCallback;
     private AudioTrackStateCallback audioTrackStateCallback;
     private AudioRecordStateCallback audioRecordStateCallback;
     private boolean useHardwareAcousticEchoCanceler = isBuiltInAcousticEchoCancelerSupported();
     private boolean useHardwareNoiseSuppressor = isBuiltInNoiseSuppressorSupported();
     private boolean useStereoInput;
     private boolean useStereoOutput;
     private AudioAttributes audioAttributes;
     private boolean useLowLatency;
     private boolean enableVolumeLogger;

     private Builder(Context context) {
       this.context = context;
       this.audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
       this.inputSampleRate = WebRtcAudioManager.getSampleRate(audioManager);
       this.outputSampleRate = WebRtcAudioManager.getSampleRate(audioManager);
       this.useLowLatency = false;
       this.enableVolumeLogger = true;
     }

     public Builder setScheduler(ScheduledExecutorService scheduler) {
       this.scheduler = scheduler;
       return this;
     }

     /**
      * Call this method if the default handling of querying the native sample rate shall be
      * overridden. Can be useful on some devices where the available Android APIs are known to
      * return invalid results.
      */
     public Builder setSampleRate(int sampleRate) {
       Logging.d(TAG, "Input/Output sample rate overridden to: " + sampleRate);
       this.inputSampleRate = sampleRate;
       this.outputSampleRate = sampleRate;
       return this;
     }

     /**
      * Call this method to specifically override input sample rate.
      */
     public Builder setInputSampleRate(int inputSampleRate) {
       Logging.d(TAG, "Input sample rate overridden to: " + inputSampleRate);
       this.inputSampleRate = inputSampleRate;
       return this;
     }

     /**
      * Call this method to specifically override output sample rate.
      */
     public Builder setOutputSampleRate(int outputSampleRate) {
       Logging.d(TAG, "Output sample rate overridden to: " + outputSampleRate);
       this.outputSampleRate = outputSampleRate;
       return this;
     }

     /**
      * Call this to change the audio source. The argument should be one of the values from
      * android.media.MediaRecorder.AudioSource. The default is AudioSource.VOICE_COMMUNICATION.
      */
     public Builder setAudioSource(int audioSource) {
       this.audioSource = audioSource;
       return this;
     }

     /**
      * Call this to change the audio format. The argument should be one of the values from
      * android.media.AudioFormat ENCODING_PCM_8BIT, ENCODING_PCM_16BIT or ENCODING_PCM_FLOAT.
      * Default audio data format is PCM 16 bit per sample.
      * Guaranteed to be supported by all devices.
      */
     public Builder setAudioFormat(int audioFormat) {
       this.audioFormat = audioFormat;
       return this;
     }

     /**
      * Set a callback to retrieve errors from the AudioTrack.
      */
     public Builder setAudioTrackErrorCallback(AudioTrackErrorCallback audioTrackErrorCallback) {
       this.audioTrackErrorCallback = audioTrackErrorCallback;
       return this;
     }

     /**
      * Set a callback to retrieve errors from the AudioRecord.
      */
     public Builder setAudioRecordErrorCallback(AudioRecordErrorCallback audioRecordErrorCallback) {
       this.audioRecordErrorCallback = audioRecordErrorCallback;
       return this;
     }

     /**
      * Set a callback to listen to the raw audio input from the AudioRecord.
      */
     public Builder setSamplesReadyCallback(SamplesReadyCallback samplesReadyCallback) {
       this.samplesReadyCallback = samplesReadyCallback;
       return this;
     }

     /**
      * Set a callback to retrieve information from the AudioTrack on when audio starts and stop.
      */
     public Builder setAudioTrackStateCallback(AudioTrackStateCallback audioTrackStateCallback) {
       this.audioTrackStateCallback = audioTrackStateCallback;
       return this;
     }

     /**
      * Set a callback to retrieve information from the AudioRecord on when audio starts and stops.
      */
     public Builder setAudioRecordStateCallback(AudioRecordStateCallback audioRecordStateCallback) {
       this.audioRecordStateCallback = audioRecordStateCallback;
       return this;
     }

     /**
      * Control if the built-in HW noise suppressor should be used or not. The default is on if it is
      * supported. It is possible to query support by calling isBuiltInNoiseSuppressorSupported().
      */
     public Builder setUseHardwareNoiseSuppressor(boolean useHardwareNoiseSuppressor) {
       if (useHardwareNoiseSuppressor && !isBuiltInNoiseSuppressorSupported()) {
         Logging.e(TAG, "HW NS not supported");
         useHardwareNoiseSuppressor = false;
       }
       this.useHardwareNoiseSuppressor = useHardwareNoiseSuppressor;
       return this;
     }

     /**
      * Control if the built-in HW acoustic echo canceler should be used or not. The default is on if
      * it is supported. It is possible to query support by calling
      * isBuiltInAcousticEchoCancelerSupported().
      */
     public Builder setUseHardwareAcousticEchoCanceler(boolean useHardwareAcousticEchoCanceler) {
       if (useHardwareAcousticEchoCanceler && !isBuiltInAcousticEchoCancelerSupported()) {
         Logging.e(TAG, "HW AEC not supported");
         useHardwareAcousticEchoCanceler = false;
       }
       this.useHardwareAcousticEchoCanceler = useHardwareAcousticEchoCanceler;
       return this;
     }

     /**
      * Control if stereo input should be used or not. The default is mono.
      */
     public Builder setUseStereoInput(boolean useStereoInput) {
       this.useStereoInput = useStereoInput;
       return this;
     }

     /**
      * Control if stereo output should be used or not. The default is mono.
      */
     public Builder setUseStereoOutput(boolean useStereoOutput) {
       this.useStereoOutput = useStereoOutput;
       return this;
     }

     /**
      * Control if the low-latency mode should be used. The default is disabled.
      */
     public Builder setUseLowLatency(boolean useLowLatency) {
       this.useLowLatency = useLowLatency;
       return this;
     }

     /**
      * Set custom {@link AudioAttributes} to use.
      */
     public Builder setAudioAttributes(AudioAttributes audioAttributes) {
       this.audioAttributes = audioAttributes;
       return this;
     }

     /** Disables the volume logger on the audio output track. */
     public Builder setEnableVolumeLogger(boolean enableVolumeLogger) {
       this.enableVolumeLogger = enableVolumeLogger;
       return this;
     }

     /**
      * Construct an AudioDeviceModule based on the supplied arguments. The caller takes ownership
      * and is responsible for calling release().
      */
     public JavaAudioDeviceModule createAudioDeviceModule() {
       Logging.d(TAG, "createAudioDeviceModule");
       if (useHardwareNoiseSuppressor) {
         Logging.d(TAG, "HW NS will be used.");
       } else {
         if (isBuiltInNoiseSuppressorSupported()) {
           Logging.d(TAG, "Overriding default behavior; now using WebRTC NS!");
         }
         Logging.d(TAG, "HW NS will not be used.");
       }
       if (useHardwareAcousticEchoCanceler) {
         Logging.d(TAG, "HW AEC will be used.");
       } else {
         if (isBuiltInAcousticEchoCancelerSupported()) {
           Logging.d(TAG, "Overriding default behavior; now using WebRTC AEC!");
         }
         Logging.d(TAG, "HW AEC will not be used.");
       }
       // Low-latency mode was introduced in API version 26, see
       // https://developer.android.com/reference/android/media/AudioTrack#PERFORMANCE_MODE_LOW_LATENCY
       final int MIN_LOW_LATENCY_SDK_VERSION = 26;
       if (useLowLatency && Build.VERSION.SDK_INT >= MIN_LOW_LATENCY_SDK_VERSION) {
         Logging.d(TAG, "Low latency mode will be used.");
       }
       ScheduledExecutorService executor = this.scheduler;
       if (executor == null) {
         executor = WebRtcAudioRecord.newDefaultScheduler();
       }
       final WebRtcAudioRecord audioInput = new WebRtcAudioRecord(context, executor, audioManager,
           audioSource, audioFormat, audioRecordErrorCallback, audioRecordStateCallback,
           samplesReadyCallback, useHardwareAcousticEchoCanceler, useHardwareNoiseSuppressor);
       final WebRtcAudioTrack audioOutput =
           new WebRtcAudioTrack(context, audioManager, audioAttributes, audioTrackErrorCallback,
               audioTrackStateCallback, useLowLatency, enableVolumeLogger);
       return new JavaAudioDeviceModule(context, audioManager, audioInput, audioOutput,
           inputSampleRate, outputSampleRate, useStereoInput, useStereoOutput);
     }
   }

   /* AudioRecord */
   // Audio recording error handler functions.
   public enum AudioRecordStartErrorCode {
     AUDIO_RECORD_START_EXCEPTION,
     AUDIO_RECORD_START_STATE_MISMATCH,
   }

   public static interface AudioRecordErrorCallback {
     void onWebRtcAudioRecordInitError(String errorMessage);
     void onWebRtcAudioRecordStartError(AudioRecordStartErrorCode errorCode, String errorMessage);
     void onWebRtcAudioRecordError(String errorMessage);
   }

   /** Called when audio recording starts and stops. */
   public static interface AudioRecordStateCallback {
     void onWebRtcAudioRecordStart();
     void onWebRtcAudioRecordStop();
   }

   /**
    * Contains audio sample information.
    */
   public static class AudioSamples {
     /** See {@link AudioRecord#getAudioFormat()} */
     private final int audioFormat;
     /** See {@link AudioRecord#getChannelCount()} */
     private final int channelCount;
     /** See {@link AudioRecord#getSampleRate()} */
     private final int sampleRate;

     private final byte[] data;

     public AudioSamples(int audioFormat, int channelCount, int sampleRate, byte[] data) {
       this.audioFormat = audioFormat;
       this.channelCount = channelCount;
       this.sampleRate = sampleRate;
       this.data = data;
     }

     public int getAudioFormat() {
       return audioFormat;
     }

     public int getChannelCount() {
       return channelCount;
     }

     public int getSampleRate() {
       return sampleRate;
     }

     public byte[] getData() {
       return data;
     }
   }

   /** Called when new audio samples are ready. This should only be set for debug purposes */
   public static interface SamplesReadyCallback {
     void onWebRtcAudioRecordSamplesReady(AudioSamples samples);
   }

   /* AudioTrack */
   // Audio playout/track error handler functions.
   public enum AudioTrackStartErrorCode {
     AUDIO_TRACK_START_EXCEPTION,
     AUDIO_TRACK_START_STATE_MISMATCH,
   }

   public static interface AudioTrackErrorCallback {
     void onWebRtcAudioTrackInitError(String errorMessage);
     void onWebRtcAudioTrackStartError(AudioTrackStartErrorCode errorCode, String errorMessage);
     void onWebRtcAudioTrackError(String errorMessage);
   }

   /** Called when audio playout starts and stops. */
   public static interface AudioTrackStateCallback {
     void onWebRtcAudioTrackStart();
     void onWebRtcAudioTrackStop();
   }

   /**
    * Returns true if the device supports built-in HW AEC, and the UUID is approved (some UUIDs can
    * be excluded).
    */
   public static boolean isBuiltInAcousticEchoCancelerSupported() {
     return WebRtcAudioEffects.isAcousticEchoCancelerSupported();
   }

   /**
    * Returns true if the device supports built-in HW NS, and the UUID is approved (some UUIDs can be
    * excluded).
    */
   public static boolean isBuiltInNoiseSuppressorSupported() {
     return WebRtcAudioEffects.isNoiseSuppressorSupported();
   }

   private final Context context;
   private final AudioManager audioManager;
   private final WebRtcAudioRecord audioInput;
   private final WebRtcAudioTrack audioOutput;
   private final int inputSampleRate;
   private final int outputSampleRate;
   private final boolean useStereoInput;
   private final boolean useStereoOutput;

   private final Object nativeLock = new Object();
   private long nativeAudioDeviceModule;

   private JavaAudioDeviceModule(Context context, AudioManager audioManager,
       WebRtcAudioRecord audioInput, WebRtcAudioTrack audioOutput, int inputSampleRate,
       int outputSampleRate, boolean useStereoInput, boolean useStereoOutput) {
     this.context = context;
     this.audioManager = audioManager;
     this.audioInput = audioInput;
     this.audioOutput = audioOutput;
     this.inputSampleRate = inputSampleRate;
     this.outputSampleRate = outputSampleRate;
     this.useStereoInput = useStereoInput;
     this.useStereoOutput = useStereoOutput;
   }

   @Override
   public long getNativeAudioDeviceModulePointer() {
     synchronized (nativeLock) {
       if (nativeAudioDeviceModule == 0) {
         nativeAudioDeviceModule = nativeCreateAudioDeviceModule(context, audioManager, audioInput,
             audioOutput, inputSampleRate, outputSampleRate, useStereoInput, useStereoOutput);
       }
       return nativeAudioDeviceModule;
     }
   }

   @Override
   public void release() {
     synchronized (nativeLock) {
       if (nativeAudioDeviceModule != 0) {
         JniCommon.nativeReleaseRef(nativeAudioDeviceModule);
         nativeAudioDeviceModule = 0;
       }
     }
   }

   @Override
   public void setSpeakerMute(boolean mute) {
     Logging.d(TAG, "setSpeakerMute: " + mute);
     audioOutput.setSpeakerMute(mute);
   }

   @Override
   public void setMicrophoneMute(boolean mute) {
     Logging.d(TAG, "setMicrophoneMute: " + mute);
     audioInput.setMicrophoneMute(mute);
   }

   /**
    * Start to prefer a specific {@link AudioDeviceInfo} device for recording. Typically this should
    * only be used if a client gives an explicit option for choosing a physical device to record
    * from. Otherwise the best-matching device for other parameters will be used. Calling after
    * recording is started may cause a temporary interruption if the audio routing changes.
    */
   @RequiresApi(Build.VERSION_CODES.M)
   public void setPreferredInputDevice(AudioDeviceInfo preferredInputDevice) {
     Logging.d(TAG, "setPreferredInputDevice: " + preferredInputDevice);
     audioInput.setPreferredDevice(preferredInputDevice);
   }

   private static native long nativeCreateAudioDeviceModule(Context context,
       AudioManager audioManager, WebRtcAudioRecord audioInput, WebRtcAudioTrack audioOutput,
       int inputSampleRate, int outputSampleRate, boolean useStereoInput, boolean useStereoOutput);
 }
	/*
	* Copyright 2018 The WebRTC project authors. All Rights Reserved.
	*
	* Use of this source code is governed by a BSD-style license
	* that can be found in the LICENSE file in the root of the source
	* tree. An additional intellectual property rights grant can be found
	* in the file PATENTS. All contributing project authors may
	* be found in the AUTHORS file in the root of the source tree.
	*/

	package org.webrtc.audio;

	import android.content.Context;
	import android.media.AudioAttributes;
	import android.media.AudioDeviceInfo;
	import android.media.AudioManager;
	import android.os.Build;
	import androidx.annotation.RequiresApi;
	import java.util.concurrent.ScheduledExecutorService;
	import org.webrtc.JniCommon;
	import org.webrtc.Logging;

	/**
	* AudioDeviceModule implemented using android.media.AudioRecord as input and
	* android.media.AudioTrack as output.
	*/
	public class JavaAudioDeviceModule implements AudioDeviceModule {
	private static final String TAG = "JavaAudioDeviceModule";

	public static Builder builder(Context context) {
	return new Builder(context);
	}

	public static class Builder {
	private final Context context;
	private ScheduledExecutorService scheduler;
	private final AudioManager audioManager;
	private int inputSampleRate;
	private int outputSampleRate;
	private int audioSource = WebRtcAudioRecord.DEFAULT_AUDIO_SOURCE;
	private int audioFormat = WebRtcAudioRecord.DEFAULT_AUDIO_FORMAT;
	private AudioTrackErrorCallback audioTrackErrorCallback;
	private AudioRecordErrorCallback audioRecordErrorCallback;
	private SamplesReadyCallback samplesReadyCallback;
	private AudioTrackStateCallback audioTrackStateCallback;
	private AudioRecordStateCallback audioRecordStateCallback;
	private boolean useHardwareAcousticEchoCanceler = isBuiltInAcousticEchoCancelerSupported();
	private boolean useHardwareNoiseSuppressor = isBuiltInNoiseSuppressorSupported();
	private boolean useStereoInput;
	private boolean useStereoOutput;
	private AudioAttributes audioAttributes;
	private boolean useLowLatency;
	private boolean enableVolumeLogger;

	private Builder(Context context) {
	this.context = context;
	this.audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
	this.inputSampleRate = WebRtcAudioManager.getSampleRate(audioManager);
	this.outputSampleRate = WebRtcAudioManager.getSampleRate(audioManager);
	this.useLowLatency = false;
	this.enableVolumeLogger = true;
	}

	public Builder setScheduler(ScheduledExecutorService scheduler) {
	this.scheduler = scheduler;
	return this;
	}

	/**
	* Call this method if the default handling of querying the native sample rate shall be
	* overridden. Can be useful on some devices where the available Android APIs are known to
	* return invalid results.
	*/
	public Builder setSampleRate(int sampleRate) {
	Logging.d(TAG, "Input/Output sample rate overridden to: " + sampleRate);
	this.inputSampleRate = sampleRate;
	this.outputSampleRate = sampleRate;
	return this;
	}

	/**
	* Call this method to specifically override input sample rate.
	*/
	public Builder setInputSampleRate(int inputSampleRate) {
	Logging.d(TAG, "Input sample rate overridden to: " + inputSampleRate);
	this.inputSampleRate = inputSampleRate;
	return this;
	}

	/**
	* Call this method to specifically override output sample rate.
	*/
	public Builder setOutputSampleRate(int outputSampleRate) {
	Logging.d(TAG, "Output sample rate overridden to: " + outputSampleRate);
	this.outputSampleRate = outputSampleRate;
	return this;
	}

	/**
	* Call this to change the audio source. The argument should be one of the values from
	* android.media.MediaRecorder.AudioSource. The default is AudioSource.VOICE_COMMUNICATION.
	*/
	public Builder setAudioSource(int audioSource) {
	this.audioSource = audioSource;
	return this;
	}

	/**
	* Call this to change the audio format. The argument should be one of the values from
	* android.media.AudioFormat ENCODING_PCM_8BIT, ENCODING_PCM_16BIT or ENCODING_PCM_FLOAT.
	* Default audio data format is PCM 16 bit per sample.
	* Guaranteed to be supported by all devices.
	*/
	public Builder setAudioFormat(int audioFormat) {
	this.audioFormat = audioFormat;
	return this;
	}

	/**
	* Set a callback to retrieve errors from the AudioTrack.
	*/
	public Builder setAudioTrackErrorCallback(AudioTrackErrorCallback audioTrackErrorCallback) {
	this.audioTrackErrorCallback = audioTrackErrorCallback;
	return this;
	}

	/**
	* Set a callback to retrieve errors from the AudioRecord.
	*/
	public Builder setAudioRecordErrorCallback(AudioRecordErrorCallback audioRecordErrorCallback) {
	this.audioRecordErrorCallback = audioRecordErrorCallback;
	return this;
	}

	/**
	* Set a callback to listen to the raw audio input from the AudioRecord.
	*/
	public Builder setSamplesReadyCallback(SamplesReadyCallback samplesReadyCallback) {
	this.samplesReadyCallback = samplesReadyCallback;
	return this;
	}

	/**
	* Set a callback to retrieve information from the AudioTrack on when audio starts and stop.
	*/
	public Builder setAudioTrackStateCallback(AudioTrackStateCallback audioTrackStateCallback) {
	this.audioTrackStateCallback = audioTrackStateCallback;
	return this;
	}

	/**
	* Set a callback to retrieve information from the AudioRecord on when audio starts and stops.
	*/
	public Builder setAudioRecordStateCallback(AudioRecordStateCallback audioRecordStateCallback) {
	this.audioRecordStateCallback = audioRecordStateCallback;
	return this;
	}

	/**
	* Control if the built-in HW noise suppressor should be used or not. The default is on if it is
	* supported. It is possible to query support by calling isBuiltInNoiseSuppressorSupported().
	*/
	public Builder setUseHardwareNoiseSuppressor(boolean useHardwareNoiseSuppressor) {
	if (useHardwareNoiseSuppressor && !isBuiltInNoiseSuppressorSupported()) {
	Logging.e(TAG, "HW NS not supported");
	useHardwareNoiseSuppressor = false;
	}
	this.useHardwareNoiseSuppressor = useHardwareNoiseSuppressor;
	return this;
	}

	/**
	* Control if the built-in HW acoustic echo canceler should be used or not. The default is on if
	* it is supported. It is possible to query support by calling
	* isBuiltInAcousticEchoCancelerSupported().
	*/
	public Builder setUseHardwareAcousticEchoCanceler(boolean useHardwareAcousticEchoCanceler) {
	if (useHardwareAcousticEchoCanceler && !isBuiltInAcousticEchoCancelerSupported()) {
	Logging.e(TAG, "HW AEC not supported");
	useHardwareAcousticEchoCanceler = false;
	}
	this.useHardwareAcousticEchoCanceler = useHardwareAcousticEchoCanceler;
	return this;
	}

	/**
	* Control if stereo input should be used or not. The default is mono.
	*/
	public Builder setUseStereoInput(boolean useStereoInput) {
	this.useStereoInput = useStereoInput;
	return this;
	}

	/**
	* Control if stereo output should be used or not. The default is mono.
	*/
	public Builder setUseStereoOutput(boolean useStereoOutput) {
	this.useStereoOutput = useStereoOutput;
	return this;
	}

	/**
	* Control if the low-latency mode should be used. The default is disabled.
	*/
	public Builder setUseLowLatency(boolean useLowLatency) {
	this.useLowLatency = useLowLatency;
	return this;
	}

	/**
	* Set custom {@link AudioAttributes} to use.
	*/
	public Builder setAudioAttributes(AudioAttributes audioAttributes) {
	this.audioAttributes = audioAttributes;
	return this;
	}

	/** Disables the volume logger on the audio output track. */
	public Builder setEnableVolumeLogger(boolean enableVolumeLogger) {
	this.enableVolumeLogger = enableVolumeLogger;
	return this;
	}

	/**
	* Construct an AudioDeviceModule based on the supplied arguments. The caller takes ownership
	* and is responsible for calling release().
	*/
	public JavaAudioDeviceModule createAudioDeviceModule() {
	Logging.d(TAG, "createAudioDeviceModule");
	if (useHardwareNoiseSuppressor) {
	Logging.d(TAG, "HW NS will be used.");
	} else {
	if (isBuiltInNoiseSuppressorSupported()) {
	Logging.d(TAG, "Overriding default behavior; now using WebRTC NS!");
	}
	Logging.d(TAG, "HW NS will not be used.");
	}
	if (useHardwareAcousticEchoCanceler) {
	Logging.d(TAG, "HW AEC will be used.");
	} else {
	if (isBuiltInAcousticEchoCancelerSupported()) {
	Logging.d(TAG, "Overriding default behavior; now using WebRTC AEC!");
	}
	Logging.d(TAG, "HW AEC will not be used.");
	}
	// Low-latency mode was introduced in API version 26, see
	// https://developer.android.com/reference/android/media/AudioTrack#PERFORMANCE_MODE_LOW_LATENCY
	final int MIN_LOW_LATENCY_SDK_VERSION = 26;
	if (useLowLatency && Build.VERSION.SDK_INT >= MIN_LOW_LATENCY_SDK_VERSION) {
	Logging.d(TAG, "Low latency mode will be used.");
	}
	ScheduledExecutorService executor = this.scheduler;
	if (executor == null) {
	executor = WebRtcAudioRecord.newDefaultScheduler();
	}
	final WebRtcAudioRecord audioInput = new WebRtcAudioRecord(context, executor, audioManager,
	audioSource, audioFormat, audioRecordErrorCallback, audioRecordStateCallback,
	samplesReadyCallback, useHardwareAcousticEchoCanceler, useHardwareNoiseSuppressor);
	final WebRtcAudioTrack audioOutput =
	new WebRtcAudioTrack(context, audioManager, audioAttributes, audioTrackErrorCallback,
	audioTrackStateCallback, useLowLatency, enableVolumeLogger);
	return new JavaAudioDeviceModule(context, audioManager, audioInput, audioOutput,
	inputSampleRate, outputSampleRate, useStereoInput, useStereoOutput);
	}
	}

	/* AudioRecord */
	// Audio recording error handler functions.
	public enum AudioRecordStartErrorCode {
	AUDIO_RECORD_START_EXCEPTION,
	AUDIO_RECORD_START_STATE_MISMATCH,
	}

	public static interface AudioRecordErrorCallback {
	void onWebRtcAudioRecordInitError(String errorMessage);
	void onWebRtcAudioRecordStartError(AudioRecordStartErrorCode errorCode, String errorMessage);
	void onWebRtcAudioRecordError(String errorMessage);
	}

	/** Called when audio recording starts and stops. */
	public static interface AudioRecordStateCallback {
	void onWebRtcAudioRecordStart();
	void onWebRtcAudioRecordStop();
	}

	/**
	* Contains audio sample information.
	*/
	public static class AudioSamples {
	/** See {@link AudioRecord#getAudioFormat()} */
	private final int audioFormat;
	/** See {@link AudioRecord#getChannelCount()} */
	private final int channelCount;
	/** See {@link AudioRecord#getSampleRate()} */
	private final int sampleRate;

	private final byte[] data;

	public AudioSamples(int audioFormat, int channelCount, int sampleRate, byte[] data) {
	this.audioFormat = audioFormat;
	this.channelCount = channelCount;
	this.sampleRate = sampleRate;
	this.data = data;
	}

	public int getAudioFormat() {
	return audioFormat;
	}

	public int getChannelCount() {
	return channelCount;
	}

	public int getSampleRate() {
	return sampleRate;
	}

	public byte[] getData() {
	return data;
	}
	}

	/** Called when new audio samples are ready. This should only be set for debug purposes */
	public static interface SamplesReadyCallback {
	void onWebRtcAudioRecordSamplesReady(AudioSamples samples);
	}

	/* AudioTrack */
	// Audio playout/track error handler functions.
	public enum AudioTrackStartErrorCode {
	AUDIO_TRACK_START_EXCEPTION,
	AUDIO_TRACK_START_STATE_MISMATCH,
	}

	public static interface AudioTrackErrorCallback {
	void onWebRtcAudioTrackInitError(String errorMessage);
	void onWebRtcAudioTrackStartError(AudioTrackStartErrorCode errorCode, String errorMessage);
	void onWebRtcAudioTrackError(String errorMessage);
	}

	/** Called when audio playout starts and stops. */
	public static interface AudioTrackStateCallback {
	void onWebRtcAudioTrackStart();
	void onWebRtcAudioTrackStop();
	}

	/**
	* Returns true if the device supports built-in HW AEC, and the UUID is approved (some UUIDs can
	* be excluded).
	*/
	public static boolean isBuiltInAcousticEchoCancelerSupported() {
	return WebRtcAudioEffects.isAcousticEchoCancelerSupported();
	}

	/**
	* Returns true if the device supports built-in HW NS, and the UUID is approved (some UUIDs can be
	* excluded).
	*/
	public static boolean isBuiltInNoiseSuppressorSupported() {
	return WebRtcAudioEffects.isNoiseSuppressorSupported();
	}

	private final Context context;
	private final AudioManager audioManager;
	private final WebRtcAudioRecord audioInput;
	private final WebRtcAudioTrack audioOutput;
	private final int inputSampleRate;
	private final int outputSampleRate;
	private final boolean useStereoInput;
	private final boolean useStereoOutput;

	private final Object nativeLock = new Object();
	private long nativeAudioDeviceModule;

	private JavaAudioDeviceModule(Context context, AudioManager audioManager,
	WebRtcAudioRecord audioInput, WebRtcAudioTrack audioOutput, int inputSampleRate,
	int outputSampleRate, boolean useStereoInput, boolean useStereoOutput) {
	this.context = context;
	this.audioManager = audioManager;
	this.audioInput = audioInput;
	this.audioOutput = audioOutput;
	this.inputSampleRate = inputSampleRate;
	this.outputSampleRate = outputSampleRate;
	this.useStereoInput = useStereoInput;
	this.useStereoOutput = useStereoOutput;
	}

	@Override
	public long getNativeAudioDeviceModulePointer() {
	synchronized (nativeLock) {
	if (nativeAudioDeviceModule == 0) {
	nativeAudioDeviceModule = nativeCreateAudioDeviceModule(context, audioManager, audioInput,
	audioOutput, inputSampleRate, outputSampleRate, useStereoInput, useStereoOutput);
	}
	return nativeAudioDeviceModule;
	}
	}

	@Override
	public void release() {
	synchronized (nativeLock) {
	if (nativeAudioDeviceModule != 0) {
	JniCommon.nativeReleaseRef(nativeAudioDeviceModule);
	nativeAudioDeviceModule = 0;
	}
	}
	}

	@Override
	public void setSpeakerMute(boolean mute) {
	Logging.d(TAG, "setSpeakerMute: " + mute);
	audioOutput.setSpeakerMute(mute);
	}

	@Override
	public void setMicrophoneMute(boolean mute) {
	Logging.d(TAG, "setMicrophoneMute: " + mute);
	audioInput.setMicrophoneMute(mute);
	}

	/**
	* Start to prefer a specific {@link AudioDeviceInfo} device for recording. Typically this should
	* only be used if a client gives an explicit option for choosing a physical device to record
	* from. Otherwise the best-matching device for other parameters will be used. Calling after
	* recording is started may cause a temporary interruption if the audio routing changes.
	*/
	@RequiresApi(Build.VERSION_CODES.M)
	public void setPreferredInputDevice(AudioDeviceInfo preferredInputDevice) {
	Logging.d(TAG, "setPreferredInputDevice: " + preferredInputDevice);
	audioInput.setPreferredDevice(preferredInputDevice);
	}

	private static native long nativeCreateAudioDeviceModule(Context context,
	AudioManager audioManager, WebRtcAudioRecord audioInput, WebRtcAudioTrack audioOutput,
	int inputSampleRate, int outputSampleRate, boolean useStereoInput, boolean useStereoOutput);
	}