webrtc/modules/audio_device/android/java/src/org/webrtc/voiceengine/WebRtcAudioEffects.java - src - Git at Google

 /*
  *  Copyright (c) 2015 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.voiceengine;

 import org.webrtc.Logging;

 import android.annotation.TargetApi;
 import android.media.audiofx.AcousticEchoCanceler;
 import android.media.audiofx.AudioEffect;
 import android.media.audiofx.AudioEffect.Descriptor;
 import android.media.audiofx.AutomaticGainControl;
 import android.media.audiofx.NoiseSuppressor;
 import android.os.Build;

 import java.util.List;
 import java.util.UUID;

 // This class wraps control of three different platform effects. Supported
 // effects are: AcousticEchoCanceler (AEC), AutomaticGainControl (AGC) and
 // NoiseSuppressor (NS). Calling enable() will active all effects that are
 // supported by the device if the corresponding |shouldEnableXXX| member is set.
 class WebRtcAudioEffects {
   private static final boolean DEBUG = false;

   private static final String TAG = "WebRtcAudioEffects";

   // UUIDs for Software Audio Effects that we want to avoid using.
   // The implementor field will be set to "The Android Open Source Project".
   private static final UUID AOSP_ACOUSTIC_ECHO_CANCELER =
       UUID.fromString("bb392ec0-8d4d-11e0-a896-0002a5d5c51b");
   private static final UUID AOSP_AUTOMATIC_GAIN_CONTROL =
       UUID.fromString("aa8130e0-66fc-11e0-bad0-0002a5d5c51b");
   private static final UUID AOSP_NOISE_SUPPRESSOR =
       UUID.fromString("c06c8400-8e06-11e0-9cb6-0002a5d5c51b");

   // Contains the available effect descriptors returned from the
   // AudioEffect.getEffects() call. This result is cached to avoid doing the
   // slow OS call multiple times.
   private static Descriptor[] cachedEffects = null;

   // Contains the audio effect objects. Created in enable() and destroyed
   // in release().
   private AcousticEchoCanceler aec = null;
   private AutomaticGainControl agc = null;
   private NoiseSuppressor ns = null;

   // Affects the final state given to the setEnabled() method on each effect.
   // The default state is set to "disabled" but each effect can also be enabled
   // by calling setAEC(), setAGC() and setNS().
   // To enable an effect, both the shouldEnableXXX member and the static
   // canUseXXX() must be true.
   private boolean shouldEnableAec = false;
   private boolean shouldEnableAgc = false;
   private boolean shouldEnableNs = false;

   // Checks if the device implements Acoustic Echo Cancellation (AEC).
   // Returns true if the device implements AEC, false otherwise.
   public static boolean isAcousticEchoCancelerSupported() {
     // Note: we're using isAcousticEchoCancelerEffectAvailable() instead of
     // AcousticEchoCanceler.isAvailable() to avoid the expensive getEffects()
     // OS API call.
     return WebRtcAudioUtils.runningOnJellyBeanOrHigher()
         && isAcousticEchoCancelerEffectAvailable();
   }

   // Checks if the device implements Automatic Gain Control (AGC).
   // Returns true if the device implements AGC, false otherwise.
   public static boolean isAutomaticGainControlSupported() {
     // Note: we're using isAutomaticGainControlEffectAvailable() instead of
     // AutomaticGainControl.isAvailable() to avoid the expensive getEffects()
     // OS API call.
     return WebRtcAudioUtils.runningOnJellyBeanOrHigher()
         && isAutomaticGainControlEffectAvailable();
   }

   // Checks if the device implements Noise Suppression (NS).
   // Returns true if the device implements NS, false otherwise.
   public static boolean isNoiseSuppressorSupported() {
     // Note: we're using isNoiseSuppressorEffectAvailable() instead of
     // NoiseSuppressor.isAvailable() to avoid the expensive getEffects()
     // OS API call.
     return WebRtcAudioUtils.runningOnJellyBeanOrHigher()
         && isNoiseSuppressorEffectAvailable();
   }

   // Returns true if the device is blacklisted for HW AEC usage.
   public static boolean isAcousticEchoCancelerBlacklisted() {
     List<String> blackListedModels =
         WebRtcAudioUtils.getBlackListedModelsForAecUsage();
     boolean isBlacklisted = blackListedModels.contains(Build.MODEL);
     if (isBlacklisted) {
       Logging.w(TAG, Build.MODEL + " is blacklisted for HW AEC usage!");
     }
     return isBlacklisted;
   }

   // Returns true if the device is blacklisted for HW AGC usage.
   public static boolean isAutomaticGainControlBlacklisted() {
    List<String> blackListedModels =
         WebRtcAudioUtils.getBlackListedModelsForAgcUsage();
     boolean isBlacklisted = blackListedModels.contains(Build.MODEL);
     if (isBlacklisted) {
       Logging.w(TAG, Build.MODEL + " is blacklisted for HW AGC usage!");
     }
     return isBlacklisted;
   }

   // Returns true if the device is blacklisted for HW NS usage.
   public static boolean isNoiseSuppressorBlacklisted() {
     List<String> blackListedModels =
         WebRtcAudioUtils.getBlackListedModelsForNsUsage();
     boolean isBlacklisted = blackListedModels.contains(Build.MODEL);
     if (isBlacklisted) {
       Logging.w(TAG, Build.MODEL + " is blacklisted for HW NS usage!");
     }
     return isBlacklisted;
   }

   // Returns true if the platform AEC should be excluded based on its UUID.
   // AudioEffect.queryEffects() can throw IllegalStateException.
   @TargetApi(18)
   private static boolean isAcousticEchoCancelerExcludedByUUID() {
     for (Descriptor d : getAvailableEffects()) {
       if (d.type.equals(AudioEffect.EFFECT_TYPE_AEC) &&
           d.uuid.equals(AOSP_ACOUSTIC_ECHO_CANCELER)) {
         return true;
       }
     }
     return false;
   }

   // Returns true if the platform AGC should be excluded based on its UUID.
   // AudioEffect.queryEffects() can throw IllegalStateException.
   @TargetApi(18)
   private static boolean isAutomaticGainControlExcludedByUUID() {
     for (Descriptor d : getAvailableEffects()) {
       if (d.type.equals(AudioEffect.EFFECT_TYPE_AGC) &&
           d.uuid.equals(AOSP_AUTOMATIC_GAIN_CONTROL)) {
         return true;
       }
     }
     return false;
   }

   // Returns true if the platform NS should be excluded based on its UUID.
   // AudioEffect.queryEffects() can throw IllegalStateException.
   @TargetApi(18)
   private static boolean isNoiseSuppressorExcludedByUUID() {
     for (Descriptor d : getAvailableEffects()) {
       if (d.type.equals(AudioEffect.EFFECT_TYPE_NS) &&
           d.uuid.equals(AOSP_NOISE_SUPPRESSOR)) {
         return true;
       }
     }
     return false;
   }

   // Returns true if the device supports Acoustic Echo Cancellation (AEC).
   @TargetApi(18)
   private static boolean isAcousticEchoCancelerEffectAvailable() {
     return isEffectTypeAvailable(AudioEffect.EFFECT_TYPE_AEC);
   }

   // Returns true if the device supports Automatic Gain Control (AGC).
   @TargetApi(18)
   private static boolean isAutomaticGainControlEffectAvailable() {
     return isEffectTypeAvailable(AudioEffect.EFFECT_TYPE_AGC);
   }

   // Returns true if the device supports Noise Suppression (NS).
   @TargetApi(18)
   private static boolean isNoiseSuppressorEffectAvailable() {
     return isEffectTypeAvailable(AudioEffect.EFFECT_TYPE_NS);
   }

   // Returns true if all conditions for supporting the HW AEC are fulfilled.
   // It will not be possible to enable the HW AEC if this method returns false.
   public static boolean canUseAcousticEchoCanceler() {
     boolean canUseAcousticEchoCanceler =
         isAcousticEchoCancelerSupported()
         && !WebRtcAudioUtils.useWebRtcBasedAcousticEchoCanceler()
         && !isAcousticEchoCancelerBlacklisted()
         && !isAcousticEchoCancelerExcludedByUUID();
     Logging.d(TAG, "canUseAcousticEchoCanceler: "
         + canUseAcousticEchoCanceler);
     return canUseAcousticEchoCanceler;
   }

   // Returns true if all conditions for supporting the HW AGC are fulfilled.
   // It will not be possible to enable the HW AGC if this method returns false.
   public static boolean canUseAutomaticGainControl() {
     boolean canUseAutomaticGainControl =
         isAutomaticGainControlSupported()
         && !WebRtcAudioUtils.useWebRtcBasedAutomaticGainControl()
         && !isAutomaticGainControlBlacklisted()
         && !isAutomaticGainControlExcludedByUUID();
     Logging.d(TAG, "canUseAutomaticGainControl: "
         + canUseAutomaticGainControl);
     return canUseAutomaticGainControl;
   }

   // Returns true if all conditions for supporting the HW NS are fulfilled.
   // It will not be possible to enable the HW NS if this method returns false.
   public static boolean canUseNoiseSuppressor() {
     boolean canUseNoiseSuppressor =
         isNoiseSuppressorSupported()
         && !WebRtcAudioUtils.useWebRtcBasedNoiseSuppressor()
         && !isNoiseSuppressorBlacklisted()
         && !isNoiseSuppressorExcludedByUUID();
     Logging.d(TAG, "canUseNoiseSuppressor: " + canUseNoiseSuppressor);
     return canUseNoiseSuppressor;
   }

   static WebRtcAudioEffects create() {
     // Return null if VoIP effects (AEC, AGC and NS) are not supported.
     if (!WebRtcAudioUtils.runningOnJellyBeanOrHigher()) {
       Logging.w(TAG, "API level 16 or higher is required!");
       return null;
     }
     return new WebRtcAudioEffects();
   }

   private WebRtcAudioEffects() {
     Logging.d(TAG, "ctor" + WebRtcAudioUtils.getThreadInfo());
   }

   // Call this method to enable or disable the platform AEC. It modifies
   // |shouldEnableAec| which is used in enable() where the actual state
   // of the AEC effect is modified. Returns true if HW AEC is supported and
   // false otherwise.
   public boolean setAEC(boolean enable) {
     Logging.d(TAG, "setAEC(" + enable + ")");
     if (!canUseAcousticEchoCanceler()) {
       Logging.w(TAG, "Platform AEC is not supported");
       shouldEnableAec = false;
       return false;
     }
     if (aec != null && (enable != shouldEnableAec)) {
       Logging.e(TAG, "Platform AEC state can't be modified while recording");
       return false;
     }
     shouldEnableAec = enable;
     return true;
   }

   // Call this method to enable or disable the platform AGC. It modifies
   // |shouldEnableAgc| which is used in enable() where the actual state
   // of the AGC effect is modified. Returns true if HW AGC is supported and
   // false otherwise.
   public boolean setAGC(boolean enable) {
     Logging.d(TAG, "setAGC(" + enable + ")");
     if (!canUseAutomaticGainControl()) {
       Logging.w(TAG, "Platform AGC is not supported");
       shouldEnableAgc = false;
       return false;
     }
     if (agc != null && (enable != shouldEnableAgc)) {
       Logging.e(TAG, "Platform AGC state can't be modified while recording");
       return false;
     }
     shouldEnableAgc = enable;
     return true;
   }

   // Call this method to enable or disable the platform NS. It modifies
   // |shouldEnableNs| which is used in enable() where the actual state
   // of the NS effect is modified. Returns true if HW NS is supported and
   // false otherwise.
   public boolean setNS(boolean enable) {
     Logging.d(TAG, "setNS(" + enable + ")");
     if (!canUseNoiseSuppressor()) {
       Logging.w(TAG, "Platform NS is not supported");
       shouldEnableNs = false;
       return false;
     }
     if (ns != null && (enable != shouldEnableNs)) {
       Logging.e(TAG, "Platform NS state can't be modified while recording");
       return false;
     }
     shouldEnableNs = enable;
     return true;
   }

   public void enable(int audioSession) {
     Logging.d(TAG, "enable(audioSession=" + audioSession + ")");
     assertTrue(aec == null);
     assertTrue(agc == null);
     assertTrue(ns == null);

     // Add logging of supported effects but filter out "VoIP effects", i.e.,
     // AEC, AEC and NS.
     for (Descriptor d : AudioEffect.queryEffects()) {
       if (effectTypeIsVoIP(d.type) || DEBUG) {
         Logging.d(TAG, "name: " + d.name + ", "
             + "mode: " + d.connectMode + ", "
             + "implementor: " + d.implementor + ", "
             + "UUID: " + d.uuid);
       }
     }

     if (isAcousticEchoCancelerSupported()) {
       // Create an AcousticEchoCanceler and attach it to the AudioRecord on
       // the specified audio session.
       aec = AcousticEchoCanceler.create(audioSession);
       if (aec != null) {
         boolean enabled = aec.getEnabled();
         boolean enable = shouldEnableAec && canUseAcousticEchoCanceler();
         if (aec.setEnabled(enable) != AudioEffect.SUCCESS) {
           Logging.e(TAG, "Failed to set the AcousticEchoCanceler state");
         }
         Logging.d(TAG, "AcousticEchoCanceler: was "
             + (enabled ? "enabled" : "disabled")
             + ", enable: " + enable + ", is now: "
             + (aec.getEnabled() ? "enabled" : "disabled"));
       } else {
         Logging.e(TAG, "Failed to create the AcousticEchoCanceler instance");
       }
     }

     if (isAutomaticGainControlSupported()) {
       // Create an AutomaticGainControl and attach it to the AudioRecord on
       // the specified audio session.
       agc = AutomaticGainControl.create(audioSession);
       if (agc != null) {
         boolean enabled = agc.getEnabled();
         boolean enable = shouldEnableAgc && canUseAutomaticGainControl();
         if (agc.setEnabled(enable) != AudioEffect.SUCCESS) {
           Logging.e(TAG, "Failed to set the AutomaticGainControl state");
         }
         Logging.d(TAG, "AutomaticGainControl: was "
             + (enabled ? "enabled" : "disabled")
             + ", enable: " + enable + ", is now: "
             + (agc.getEnabled() ? "enabled" : "disabled"));
       } else {
         Logging.e(TAG, "Failed to create the AutomaticGainControl instance");
       }
     }

     if (isNoiseSuppressorSupported()) {
       // Create an NoiseSuppressor and attach it to the AudioRecord on the
       // specified audio session.
       ns = NoiseSuppressor.create(audioSession);
       if (ns != null) {
         boolean enabled = ns.getEnabled();
         boolean enable = shouldEnableNs && canUseNoiseSuppressor();
         if (ns.setEnabled(enable) != AudioEffect.SUCCESS) {
           Logging.e(TAG, "Failed to set the NoiseSuppressor state");
         }
         Logging.d(TAG, "NoiseSuppressor: was "
             + (enabled ? "enabled" : "disabled")
             + ", enable: " + enable + ", is now: "
             + (ns.getEnabled() ? "enabled" : "disabled"));
       } else {
         Logging.e(TAG, "Failed to create the NoiseSuppressor instance");
       }
     }
   }

   // Releases all native audio effect resources. It is a good practice to
   // release the effect engine when not in use as control can be returned
   // to other applications or the native resources released.
   public void release() {
     Logging.d(TAG, "release");
     if (aec != null) {
       aec.release();
       aec = null;
     }
     if (agc != null) {
       agc.release();
       agc = null;
     }
     if (ns != null) {
       ns.release();
       ns = null;
     }
   }

   // Returns true for effect types in |type| that are of "VoIP" types:
   // Acoustic Echo Canceler (AEC) or Automatic Gain Control (AGC) or
   // Noise Suppressor (NS). Note that, an extra check for support is needed
   // in each comparison since some devices includes effects in the
   // AudioEffect.Descriptor array that are actually not available on the device.
   // As an example: Samsung Galaxy S6 includes an AGC in the descriptor but
   // AutomaticGainControl.isAvailable() returns false.
   @TargetApi(18)
   private boolean effectTypeIsVoIP(UUID type) {
     if (!WebRtcAudioUtils.runningOnJellyBeanMR2OrHigher())
       return false;

     return (AudioEffect.EFFECT_TYPE_AEC.equals(type)
         && isAcousticEchoCancelerSupported())
         || (AudioEffect.EFFECT_TYPE_AGC.equals(type)
         && isAutomaticGainControlSupported())
         || (AudioEffect.EFFECT_TYPE_NS.equals(type)
         && isNoiseSuppressorSupported());
   }

   // Helper method which throws an exception when an assertion has failed.
   private static void assertTrue(boolean condition) {
     if (!condition) {
       throw new AssertionError("Expected condition to be true");
     }
   }

   // Returns the cached copy of the audio effects array, if available, or
   // queries the operating system for the list of effects.
   private static Descriptor[] getAvailableEffects() {
     if (cachedEffects != null) {
       return cachedEffects;
     }
     // The caching is best effort only - if this method is called from several
     // threads in parallel, they may end up doing the underlying OS call
     // multiple times. It's normally only called on one thread so there's no
     // real need to optimize for the multiple threads case.
     cachedEffects = AudioEffect.queryEffects();
     return cachedEffects;
   }

   // Returns true if an effect of the specified type is available. Functionally
   // equivalent to (NoiseSuppressor|AutomaticGainControl|...).isAvailable(), but
   // faster as it avoids the expensive OS call to enumerate effects.
   private static boolean isEffectTypeAvailable(UUID effectType) {
     Descriptor[] effects = getAvailableEffects();
     if (effects == null) {
       return false;
     }
     for (Descriptor d : effects) {
       if (d.type.equals(effectType)) {
         return true;
       }
     }
     return false;
   }
 }
	/*
	* Copyright (c) 2015 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.voiceengine;

	import org.webrtc.Logging;

	import android.annotation.TargetApi;
	import android.media.audiofx.AcousticEchoCanceler;
	import android.media.audiofx.AudioEffect;
	import android.media.audiofx.AudioEffect.Descriptor;
	import android.media.audiofx.AutomaticGainControl;
	import android.media.audiofx.NoiseSuppressor;
	import android.os.Build;

	import java.util.List;
	import java.util.UUID;

	// This class wraps control of three different platform effects. Supported
	// effects are: AcousticEchoCanceler (AEC), AutomaticGainControl (AGC) and
	// NoiseSuppressor (NS). Calling enable() will active all effects that are
	// supported by the device if the corresponding \|shouldEnableXXX\| member is set.
	class WebRtcAudioEffects {
	private static final boolean DEBUG = false;

	private static final String TAG = "WebRtcAudioEffects";

	// UUIDs for Software Audio Effects that we want to avoid using.
	// The implementor field will be set to "The Android Open Source Project".
	private static final UUID AOSP_ACOUSTIC_ECHO_CANCELER =
	UUID.fromString("bb392ec0-8d4d-11e0-a896-0002a5d5c51b");
	private static final UUID AOSP_AUTOMATIC_GAIN_CONTROL =
	UUID.fromString("aa8130e0-66fc-11e0-bad0-0002a5d5c51b");
	private static final UUID AOSP_NOISE_SUPPRESSOR =
	UUID.fromString("c06c8400-8e06-11e0-9cb6-0002a5d5c51b");

	// Contains the available effect descriptors returned from the
	// AudioEffect.getEffects() call. This result is cached to avoid doing the
	// slow OS call multiple times.
	private static Descriptor[] cachedEffects = null;

	// Contains the audio effect objects. Created in enable() and destroyed
	// in release().
	private AcousticEchoCanceler aec = null;
	private AutomaticGainControl agc = null;
	private NoiseSuppressor ns = null;

	// Affects the final state given to the setEnabled() method on each effect.
	// The default state is set to "disabled" but each effect can also be enabled
	// by calling setAEC(), setAGC() and setNS().
	// To enable an effect, both the shouldEnableXXX member and the static
	// canUseXXX() must be true.
	private boolean shouldEnableAec = false;
	private boolean shouldEnableAgc = false;
	private boolean shouldEnableNs = false;

	// Checks if the device implements Acoustic Echo Cancellation (AEC).
	// Returns true if the device implements AEC, false otherwise.
	public static boolean isAcousticEchoCancelerSupported() {
	// Note: we're using isAcousticEchoCancelerEffectAvailable() instead of
	// AcousticEchoCanceler.isAvailable() to avoid the expensive getEffects()
	// OS API call.
	return WebRtcAudioUtils.runningOnJellyBeanOrHigher()
	&& isAcousticEchoCancelerEffectAvailable();
	}

	// Checks if the device implements Automatic Gain Control (AGC).
	// Returns true if the device implements AGC, false otherwise.
	public static boolean isAutomaticGainControlSupported() {
	// Note: we're using isAutomaticGainControlEffectAvailable() instead of
	// AutomaticGainControl.isAvailable() to avoid the expensive getEffects()
	// OS API call.
	return WebRtcAudioUtils.runningOnJellyBeanOrHigher()
	&& isAutomaticGainControlEffectAvailable();
	}

	// Checks if the device implements Noise Suppression (NS).
	// Returns true if the device implements NS, false otherwise.
	public static boolean isNoiseSuppressorSupported() {
	// Note: we're using isNoiseSuppressorEffectAvailable() instead of
	// NoiseSuppressor.isAvailable() to avoid the expensive getEffects()
	// OS API call.
	return WebRtcAudioUtils.runningOnJellyBeanOrHigher()
	&& isNoiseSuppressorEffectAvailable();
	}

	// Returns true if the device is blacklisted for HW AEC usage.
	public static boolean isAcousticEchoCancelerBlacklisted() {
	List<String> blackListedModels =
	WebRtcAudioUtils.getBlackListedModelsForAecUsage();
	boolean isBlacklisted = blackListedModels.contains(Build.MODEL);
	if (isBlacklisted) {
	Logging.w(TAG, Build.MODEL + " is blacklisted for HW AEC usage!");
	}
	return isBlacklisted;
	}

	// Returns true if the device is blacklisted for HW AGC usage.
	public static boolean isAutomaticGainControlBlacklisted() {
	List<String> blackListedModels =
	WebRtcAudioUtils.getBlackListedModelsForAgcUsage();
	boolean isBlacklisted = blackListedModels.contains(Build.MODEL);
	if (isBlacklisted) {
	Logging.w(TAG, Build.MODEL + " is blacklisted for HW AGC usage!");
	}
	return isBlacklisted;
	}

	// Returns true if the device is blacklisted for HW NS usage.
	public static boolean isNoiseSuppressorBlacklisted() {
	List<String> blackListedModels =
	WebRtcAudioUtils.getBlackListedModelsForNsUsage();
	boolean isBlacklisted = blackListedModels.contains(Build.MODEL);
	if (isBlacklisted) {
	Logging.w(TAG, Build.MODEL + " is blacklisted for HW NS usage!");
	}
	return isBlacklisted;
	}

	// Returns true if the platform AEC should be excluded based on its UUID.
	// AudioEffect.queryEffects() can throw IllegalStateException.
	@TargetApi(18)
	private static boolean isAcousticEchoCancelerExcludedByUUID() {
	for (Descriptor d : getAvailableEffects()) {
	if (d.type.equals(AudioEffect.EFFECT_TYPE_AEC) &&
	d.uuid.equals(AOSP_ACOUSTIC_ECHO_CANCELER)) {
	return true;
	}
	}
	return false;
	}

	// Returns true if the platform AGC should be excluded based on its UUID.
	// AudioEffect.queryEffects() can throw IllegalStateException.
	@TargetApi(18)
	private static boolean isAutomaticGainControlExcludedByUUID() {
	for (Descriptor d : getAvailableEffects()) {
	if (d.type.equals(AudioEffect.EFFECT_TYPE_AGC) &&
	d.uuid.equals(AOSP_AUTOMATIC_GAIN_CONTROL)) {
	return true;
	}
	}
	return false;
	}

	// Returns true if the platform NS should be excluded based on its UUID.
	// AudioEffect.queryEffects() can throw IllegalStateException.
	@TargetApi(18)
	private static boolean isNoiseSuppressorExcludedByUUID() {
	for (Descriptor d : getAvailableEffects()) {
	if (d.type.equals(AudioEffect.EFFECT_TYPE_NS) &&
	d.uuid.equals(AOSP_NOISE_SUPPRESSOR)) {
	return true;
	}
	}
	return false;
	}

	// Returns true if the device supports Acoustic Echo Cancellation (AEC).
	@TargetApi(18)
	private static boolean isAcousticEchoCancelerEffectAvailable() {
	return isEffectTypeAvailable(AudioEffect.EFFECT_TYPE_AEC);
	}

	// Returns true if the device supports Automatic Gain Control (AGC).
	@TargetApi(18)
	private static boolean isAutomaticGainControlEffectAvailable() {
	return isEffectTypeAvailable(AudioEffect.EFFECT_TYPE_AGC);
	}

	// Returns true if the device supports Noise Suppression (NS).
	@TargetApi(18)
	private static boolean isNoiseSuppressorEffectAvailable() {
	return isEffectTypeAvailable(AudioEffect.EFFECT_TYPE_NS);
	}

	// Returns true if all conditions for supporting the HW AEC are fulfilled.
	// It will not be possible to enable the HW AEC if this method returns false.
	public static boolean canUseAcousticEchoCanceler() {
	boolean canUseAcousticEchoCanceler =
	isAcousticEchoCancelerSupported()
	&& !WebRtcAudioUtils.useWebRtcBasedAcousticEchoCanceler()
	&& !isAcousticEchoCancelerBlacklisted()
	&& !isAcousticEchoCancelerExcludedByUUID();
	Logging.d(TAG, "canUseAcousticEchoCanceler: "
	+ canUseAcousticEchoCanceler);
	return canUseAcousticEchoCanceler;
	}

	// Returns true if all conditions for supporting the HW AGC are fulfilled.
	// It will not be possible to enable the HW AGC if this method returns false.
	public static boolean canUseAutomaticGainControl() {
	boolean canUseAutomaticGainControl =
	isAutomaticGainControlSupported()
	&& !WebRtcAudioUtils.useWebRtcBasedAutomaticGainControl()
	&& !isAutomaticGainControlBlacklisted()
	&& !isAutomaticGainControlExcludedByUUID();
	Logging.d(TAG, "canUseAutomaticGainControl: "
	+ canUseAutomaticGainControl);
	return canUseAutomaticGainControl;
	}

	// Returns true if all conditions for supporting the HW NS are fulfilled.
	// It will not be possible to enable the HW NS if this method returns false.
	public static boolean canUseNoiseSuppressor() {
	boolean canUseNoiseSuppressor =
	isNoiseSuppressorSupported()
	&& !WebRtcAudioUtils.useWebRtcBasedNoiseSuppressor()
	&& !isNoiseSuppressorBlacklisted()
	&& !isNoiseSuppressorExcludedByUUID();
	Logging.d(TAG, "canUseNoiseSuppressor: " + canUseNoiseSuppressor);
	return canUseNoiseSuppressor;
	}

	static WebRtcAudioEffects create() {
	// Return null if VoIP effects (AEC, AGC and NS) are not supported.
	if (!WebRtcAudioUtils.runningOnJellyBeanOrHigher()) {
	Logging.w(TAG, "API level 16 or higher is required!");
	return null;
	}
	return new WebRtcAudioEffects();
	}

	private WebRtcAudioEffects() {
	Logging.d(TAG, "ctor" + WebRtcAudioUtils.getThreadInfo());
	}

	// Call this method to enable or disable the platform AEC. It modifies
	// \|shouldEnableAec\| which is used in enable() where the actual state
	// of the AEC effect is modified. Returns true if HW AEC is supported and
	// false otherwise.
	public boolean setAEC(boolean enable) {
	Logging.d(TAG, "setAEC(" + enable + ")");
	if (!canUseAcousticEchoCanceler()) {
	Logging.w(TAG, "Platform AEC is not supported");
	shouldEnableAec = false;
	return false;
	}
	if (aec != null && (enable != shouldEnableAec)) {
	Logging.e(TAG, "Platform AEC state can't be modified while recording");
	return false;
	}
	shouldEnableAec = enable;
	return true;
	}

	// Call this method to enable or disable the platform AGC. It modifies
	// \|shouldEnableAgc\| which is used in enable() where the actual state
	// of the AGC effect is modified. Returns true if HW AGC is supported and
	// false otherwise.
	public boolean setAGC(boolean enable) {
	Logging.d(TAG, "setAGC(" + enable + ")");
	if (!canUseAutomaticGainControl()) {
	Logging.w(TAG, "Platform AGC is not supported");
	shouldEnableAgc = false;
	return false;
	}
	if (agc != null && (enable != shouldEnableAgc)) {
	Logging.e(TAG, "Platform AGC state can't be modified while recording");
	return false;
	}
	shouldEnableAgc = enable;
	return true;
	}

	// Call this method to enable or disable the platform NS. It modifies
	// \|shouldEnableNs\| which is used in enable() where the actual state
	// of the NS effect is modified. Returns true if HW NS is supported and
	// false otherwise.
	public boolean setNS(boolean enable) {
	Logging.d(TAG, "setNS(" + enable + ")");
	if (!canUseNoiseSuppressor()) {
	Logging.w(TAG, "Platform NS is not supported");
	shouldEnableNs = false;
	return false;
	}
	if (ns != null && (enable != shouldEnableNs)) {
	Logging.e(TAG, "Platform NS state can't be modified while recording");
	return false;
	}
	shouldEnableNs = enable;
	return true;
	}

	public void enable(int audioSession) {
	Logging.d(TAG, "enable(audioSession=" + audioSession + ")");
	assertTrue(aec == null);
	assertTrue(agc == null);
	assertTrue(ns == null);

	// Add logging of supported effects but filter out "VoIP effects", i.e.,
	// AEC, AEC and NS.
	for (Descriptor d : AudioEffect.queryEffects()) {
	if (effectTypeIsVoIP(d.type) \|\| DEBUG) {
	Logging.d(TAG, "name: " + d.name + ", "
	+ "mode: " + d.connectMode + ", "
	+ "implementor: " + d.implementor + ", "
	+ "UUID: " + d.uuid);
	}
	}

	if (isAcousticEchoCancelerSupported()) {
	// Create an AcousticEchoCanceler and attach it to the AudioRecord on
	// the specified audio session.
	aec = AcousticEchoCanceler.create(audioSession);
	if (aec != null) {
	boolean enabled = aec.getEnabled();
	boolean enable = shouldEnableAec && canUseAcousticEchoCanceler();
	if (aec.setEnabled(enable) != AudioEffect.SUCCESS) {
	Logging.e(TAG, "Failed to set the AcousticEchoCanceler state");
	}
	Logging.d(TAG, "AcousticEchoCanceler: was "
	+ (enabled ? "enabled" : "disabled")
	+ ", enable: " + enable + ", is now: "
	+ (aec.getEnabled() ? "enabled" : "disabled"));
	} else {
	Logging.e(TAG, "Failed to create the AcousticEchoCanceler instance");
	}
	}

	if (isAutomaticGainControlSupported()) {
	// Create an AutomaticGainControl and attach it to the AudioRecord on
	// the specified audio session.
	agc = AutomaticGainControl.create(audioSession);
	if (agc != null) {
	boolean enabled = agc.getEnabled();
	boolean enable = shouldEnableAgc && canUseAutomaticGainControl();
	if (agc.setEnabled(enable) != AudioEffect.SUCCESS) {
	Logging.e(TAG, "Failed to set the AutomaticGainControl state");
	}
	Logging.d(TAG, "AutomaticGainControl: was "
	+ (enabled ? "enabled" : "disabled")
	+ ", enable: " + enable + ", is now: "
	+ (agc.getEnabled() ? "enabled" : "disabled"));
	} else {
	Logging.e(TAG, "Failed to create the AutomaticGainControl instance");
	}
	}

	if (isNoiseSuppressorSupported()) {
	// Create an NoiseSuppressor and attach it to the AudioRecord on the
	// specified audio session.
	ns = NoiseSuppressor.create(audioSession);
	if (ns != null) {
	boolean enabled = ns.getEnabled();
	boolean enable = shouldEnableNs && canUseNoiseSuppressor();
	if (ns.setEnabled(enable) != AudioEffect.SUCCESS) {
	Logging.e(TAG, "Failed to set the NoiseSuppressor state");
	}
	Logging.d(TAG, "NoiseSuppressor: was "
	+ (enabled ? "enabled" : "disabled")
	+ ", enable: " + enable + ", is now: "
	+ (ns.getEnabled() ? "enabled" : "disabled"));
	} else {
	Logging.e(TAG, "Failed to create the NoiseSuppressor instance");
	}
	}
	}

	// Releases all native audio effect resources. It is a good practice to
	// release the effect engine when not in use as control can be returned
	// to other applications or the native resources released.
	public void release() {
	Logging.d(TAG, "release");
	if (aec != null) {
	aec.release();
	aec = null;
	}
	if (agc != null) {
	agc.release();
	agc = null;
	}
	if (ns != null) {
	ns.release();
	ns = null;
	}
	}

	// Returns true for effect types in \|type\| that are of "VoIP" types:
	// Acoustic Echo Canceler (AEC) or Automatic Gain Control (AGC) or
	// Noise Suppressor (NS). Note that, an extra check for support is needed
	// in each comparison since some devices includes effects in the
	// AudioEffect.Descriptor array that are actually not available on the device.
	// As an example: Samsung Galaxy S6 includes an AGC in the descriptor but
	// AutomaticGainControl.isAvailable() returns false.
	@TargetApi(18)
	private boolean effectTypeIsVoIP(UUID type) {
	if (!WebRtcAudioUtils.runningOnJellyBeanMR2OrHigher())
	return false;

	return (AudioEffect.EFFECT_TYPE_AEC.equals(type)
	&& isAcousticEchoCancelerSupported())
	\|\| (AudioEffect.EFFECT_TYPE_AGC.equals(type)
	&& isAutomaticGainControlSupported())
	\|\| (AudioEffect.EFFECT_TYPE_NS.equals(type)
	&& isNoiseSuppressorSupported());
	}

	// Helper method which throws an exception when an assertion has failed.
	private static void assertTrue(boolean condition) {
	if (!condition) {
	throw new AssertionError("Expected condition to be true");
	}
	}

	// Returns the cached copy of the audio effects array, if available, or
	// queries the operating system for the list of effects.
	private static Descriptor[] getAvailableEffects() {
	if (cachedEffects != null) {
	return cachedEffects;
	}
	// The caching is best effort only - if this method is called from several
	// threads in parallel, they may end up doing the underlying OS call
	// multiple times. It's normally only called on one thread so there's no
	// real need to optimize for the multiple threads case.
	cachedEffects = AudioEffect.queryEffects();
	return cachedEffects;
	}

	// Returns true if an effect of the specified type is available. Functionally
	// equivalent to (NoiseSuppressor\|AutomaticGainControl\|...).isAvailable(), but
	// faster as it avoids the expensive OS call to enumerate effects.
	private static boolean isEffectTypeAvailable(UUID effectType) {
	Descriptor[] effects = getAvailableEffects();
	if (effects == null) {
	return false;
	}
	for (Descriptor d : effects) {
	if (d.type.equals(effectType)) {
	return true;
	}
	}
	return false;
	}
	}