https://source.android.com/ 
/*
 * Copyright (C) 2014 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 android.annotation.IntDef;
import android.annotation.NonNull;
import android.annotation.SystemApi;
import android.os.Bundle;
import android.os.Parcel;
import android.os.Parcelable;
import android.text.TextUtils;
import android.util.Log;
import android.util.SparseIntArray;
import android.util.proto.ProtoOutputStream;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.Collections;
import java.util.HashSet;
import java.util.Objects;
import java.util.Set;


A class to encapsulate a collection of attributes describing information about an audio
stream.

AudioAttributes supersede the notion of stream types (see for instance AudioManager.STREAM_MUSIC or AudioManager.STREAM_ALARM) for defining the behavior of audio playback. Attributes allow an application to specify more information than is conveyed in a stream type by allowing the application to define: 
    

  • usage: "why" you are playing a sound, what is this sound used for. This is achieved with the "usage" information. Examples of usage are USAGE_MEDIA and USAGE_ALARM. These two examples are the closest to stream types, but more detailed use cases are available. Usage information is more expressive than a stream type, and allows certain platforms or routing policies to use this information for more refined volume or routing decisions. Usage is the most important information to supply in AudioAttributes and it is recommended to build any instance with this information supplied, see Builder for exceptions.
    • 

  • content type: "what" you are playing. The content type expresses the general category of the content. This information is optional. But in case it is known (for instance CONTENT_TYPE_MOVIE for a movie streaming service or CONTENT_TYPE_MUSIC for a music playback application) this information might be used by the audio framework to selectively configure some audio post-processing blocks.
    • 

  • flags: "how" is playback to be affected, see the flag definitions for the specific playback
    behaviors they control. 
    • 



AudioAttributes are used for example in one of the AudioTrack constructors (see AudioTrack(AudioAttributes, AudioFormat, int, int, int)), to configure a MediaPlayer (see MediaPlayer.setAudioAttributes(AudioAttributes) or a Notification (see Notification.audioAttributes). An AudioAttributes instance is built through its builder, Builder. 
/**
 * A class to encapsulate a collection of attributes describing information about an audio
 * stream.
 * <p><code>AudioAttributes</code> supersede the notion of stream types (see for instance
 * {@link AudioManager#STREAM_MUSIC} or {@link AudioManager#STREAM_ALARM}) for defining the
 * behavior of audio playback. Attributes allow an application to specify more information than is
 * conveyed in a stream type by allowing the application to define:
 * <ul>
 * <li>usage: "why" you are playing a sound, what is this sound used for. This is achieved with
 *     the "usage" information. Examples of usage are {@link #USAGE_MEDIA} and {@link #USAGE_ALARM}.
 *     These two examples are the closest to stream types, but more detailed use cases are
 *     available. Usage information is more expressive than a stream type, and allows certain
 *     platforms or routing policies to use this information for more refined volume or routing
 *     decisions. Usage is the most important information to supply in <code>AudioAttributes</code>
 *     and it is recommended to build any instance with this information supplied, see
 *     {@link AudioAttributes.Builder} for exceptions.</li>
 * <li>content type: "what" you are playing. The content type expresses the general category of
 *     the content. This information is optional. But in case it is known (for instance
 *     {@link #CONTENT_TYPE_MOVIE} for a movie streaming service or {@link #CONTENT_TYPE_MUSIC} for
 *     a music playback application) this information might be used by the audio framework to
 *     selectively configure some audio post-processing blocks.</li>
 * <li>flags: "how" is playback to be affected, see the flag definitions for the specific playback
 *     behaviors they control. </li>
 * </ul>
 * <p><code>AudioAttributes</code> are used for example in one of the {@link AudioTrack}
 * constructors (see {@link AudioTrack#AudioTrack(AudioAttributes, AudioFormat, int, int, int)}),
 * to configure a {@link MediaPlayer}
 * (see {@link MediaPlayer#setAudioAttributes(AudioAttributes)} or a
 * {@link android.app.Notification} (see {@link android.app.Notification#audioAttributes}). An
 * <code>AudioAttributes</code> instance is built through its builder,
 * {@link AudioAttributes.Builder}.
 */
public final class AudioAttributes implements Parcelable {
    private final static String TAG = "AudioAttributes";

    
Content type value to use when the content type is unknown, or other than the ones defined.

/**
     * Content type value to use when the content type is unknown, or other than the ones defined.
     */
    public final static int CONTENT_TYPE_UNKNOWN = 0;
    
Content type value to use when the content type is speech.

/**
     * Content type value to use when the content type is speech.
     */
    public final static int CONTENT_TYPE_SPEECH = 1;
    
Content type value to use when the content type is music.

/**
     * Content type value to use when the content type is music.
     */
    public final static int CONTENT_TYPE_MUSIC = 2;
    
Content type value to use when the content type is a soundtrack, typically accompanying
a movie or TV program.

/**
     * Content type value to use when the content type is a soundtrack, typically accompanying
     * a movie or TV program.
     */
    public final static int CONTENT_TYPE_MOVIE = 3;
    
Content type value to use when the content type is a sound used to accompany a user
action, such as a beep or sound effect expressing a key click, or event, such as the
type of a sound for a bonus being received in a game. These sounds are mostly synthesized
or short Foley sounds.

/**
     * Content type value to use when the content type is a sound used to accompany a user
     * action, such as a beep or sound effect expressing a key click, or event, such as the
     * type of a sound for a bonus being received in a game. These sounds are mostly synthesized
     * or short Foley sounds.
     */
    public final static int CONTENT_TYPE_SONIFICATION = 4;

    
Usage value to use when the usage is unknown.

/**
     * Usage value to use when the usage is unknown.
     */
    public final static int USAGE_UNKNOWN = 0;
    
Usage value to use when the usage is media, such as music, or movie
soundtracks.

/**
     * Usage value to use when the usage is media, such as music, or movie
     * soundtracks.
     */
    public final static int USAGE_MEDIA = 1;
    
Usage value to use when the usage is voice communications, such as telephony
or VoIP.

/**
     * Usage value to use when the usage is voice communications, such as telephony
     * or VoIP.
     */
    public final static int USAGE_VOICE_COMMUNICATION = 2;
    
Usage value to use when the usage is in-call signalling, such as with
a "busy" beep, or DTMF tones.

/**
     * Usage value to use when the usage is in-call signalling, such as with
     * a "busy" beep, or DTMF tones.
     */
    public final static int USAGE_VOICE_COMMUNICATION_SIGNALLING = 3;
    
Usage value to use when the usage is an alarm (e.g. wake-up alarm).

/**
     * Usage value to use when the usage is an alarm (e.g. wake-up alarm).
     */
    public final static int USAGE_ALARM = 4;
    
Usage value to use when the usage is notification. See other
notification usages for more specialized uses.

/**
     * Usage value to use when the usage is notification. See other
     * notification usages for more specialized uses.
     */
    public final static int USAGE_NOTIFICATION = 5;
    
Usage value to use when the usage is telephony ringtone.

/**
     * Usage value to use when the usage is telephony ringtone.
     */
    public final static int USAGE_NOTIFICATION_RINGTONE = 6;
    
Usage value to use when the usage is a request to enter/end a
communication, such as a VoIP communication or video-conference.

/**
     * Usage value to use when the usage is a request to enter/end a
     * communication, such as a VoIP communication or video-conference.
     */
    public final static int USAGE_NOTIFICATION_COMMUNICATION_REQUEST = 7;
    
Usage value to use when the usage is notification for an "instant"
communication such as a chat, or SMS.

/**
     * Usage value to use when the usage is notification for an "instant"
     * communication such as a chat, or SMS.
     */
    public final static int USAGE_NOTIFICATION_COMMUNICATION_INSTANT = 8;
    
Usage value to use when the usage is notification for a
non-immediate type of communication such as e-mail.

/**
     * Usage value to use when the usage is notification for a
     * non-immediate type of communication such as e-mail.
     */
    public final static int USAGE_NOTIFICATION_COMMUNICATION_DELAYED = 9;
    
Usage value to use when the usage is to attract the user's attention,
such as a reminder or low battery warning.

/**
     * Usage value to use when the usage is to attract the user's attention,
     * such as a reminder or low battery warning.
     */
    public final static int USAGE_NOTIFICATION_EVENT = 10;
    
Usage value to use when the usage is for accessibility, such as with
a screen reader.

/**
     * Usage value to use when the usage is for accessibility, such as with
     * a screen reader.
     */
    public final static int USAGE_ASSISTANCE_ACCESSIBILITY = 11;
    
Usage value to use when the usage is driving or navigation directions.

/**
     * Usage value to use when the usage is driving or navigation directions.
     */
    public final static int USAGE_ASSISTANCE_NAVIGATION_GUIDANCE = 12;
    
Usage value to use when the usage is sonification, such as  with user
interface sounds.

/**
     * Usage value to use when the usage is sonification, such as  with user
     * interface sounds.
     */
    public final static int USAGE_ASSISTANCE_SONIFICATION = 13;
    
Usage value to use when the usage is for game audio.

/**
     * Usage value to use when the usage is for game audio.
     */
    public final static int USAGE_GAME = 14;
    
@hide
Usage value to use when feeding audio to the platform and replacing "traditional" audio
source, such as audio capture devices.
/**
     * @hide
     * Usage value to use when feeding audio to the platform and replacing "traditional" audio
     * source, such as audio capture devices.
     */
    public final static int USAGE_VIRTUAL_SOURCE = 15;
    
Usage value to use for audio responses to user queries, audio instructions or help
utterances.

/**
     * Usage value to use for audio responses to user queries, audio instructions or help
     * utterances.
     */
    public final static int USAGE_ASSISTANT = 16;

    /**
     * IMPORTANT: when adding new usage types, add them to SDK_USAGES and update SUPPRESSIBLE_USAGES
     *            if applicable, as well as audioattributes.proto.
     *            Also consider adding them to <aaudio/AAudio.h> for the NDK.
     *            Also consider adding them to UsageTypeConverter for service dump and etc.
     */

    
See Also:
@hide
Denotes a usage for notifications that do not expect immediate intervention from the user,
will be muted when the Zen mode disables notifications
/**
     * @hide
     * Denotes a usage for notifications that do not expect immediate intervention from the user,
     * will be muted when the Zen mode disables notifications
     * @see #SUPPRESSIBLE_USAGES
     */
    public final static int SUPPRESSIBLE_NOTIFICATION = 1;
    
See Also:
@hide
Denotes a usage for notifications that do expect immediate intervention from the user,
will be muted when the Zen mode disables calls
/**
     * @hide
     * Denotes a usage for notifications that do expect immediate intervention from the user,
     * will be muted when the Zen mode disables calls
     * @see #SUPPRESSIBLE_USAGES
     */
    public final static int SUPPRESSIBLE_CALL = 2;
    
See Also:
@hide
Denotes a usage that is never going to be muted, even in Total Silence.
/**
     * @hide
     * Denotes a usage that is never going to be muted, even in Total Silence.
     * @see #SUPPRESSIBLE_USAGES
     */
    public final static int SUPPRESSIBLE_NEVER = 3;
    
See Also:
@hide
Denotes a usage for alarms,
will be muted when the Zen mode priority doesn't allow alarms or in Alarms Only Mode
/**
     * @hide
     * Denotes a usage for alarms,
     * will be muted when the Zen mode priority doesn't allow alarms or in Alarms Only Mode
     * @see #SUPPRESSIBLE_USAGES
     */
    public final static int SUPPRESSIBLE_ALARM = 4;
    
See Also:
@hide
Denotes a usage for media, game, assistant, and navigation
will be muted when the Zen priority mode doesn't allow media
/**
     * @hide
     * Denotes a usage for media, game, assistant, and navigation
     * will be muted when the Zen priority mode doesn't allow media
     * @see #SUPPRESSIBLE_USAGES
     */
    public final static int SUPPRESSIBLE_MEDIA = 5;
    
See Also:
@hide
Denotes a usage for all other sounds not caught in SUPPRESSIBLE_NOTIFICATION,
SUPPRESSIBLE_CALL,SUPPRESSIBLE_NEVER, SUPPRESSIBLE_ALARM or SUPPRESSIBLE_MEDIA.
This includes system, sonification and unknown sounds.
These will be muted when the Zen priority mode doesn't allow sytem sounds
/**
     * @hide
     * Denotes a usage for all other sounds not caught in SUPPRESSIBLE_NOTIFICATION,
     * SUPPRESSIBLE_CALL,SUPPRESSIBLE_NEVER, SUPPRESSIBLE_ALARM or SUPPRESSIBLE_MEDIA.
     * This includes system, sonification and unknown sounds.
     * These will be muted when the Zen priority mode doesn't allow sytem sounds
     * @see #SUPPRESSIBLE_USAGES
     */
    public final static int SUPPRESSIBLE_SYSTEM = 6;

    
See Also:
  • ZenModeHelper
@hide
Array of all usage types for calls and notifications to assign the suppression behavior,
used by the Zen mode restrictions.
/**
     * @hide
     * Array of all usage types for calls and notifications to assign the suppression behavior,
     * used by the Zen mode restrictions.
     * @see com.android.server.notification.ZenModeHelper
     */
    public static final SparseIntArray SUPPRESSIBLE_USAGES;

    static {
        SUPPRESSIBLE_USAGES = new SparseIntArray();
        SUPPRESSIBLE_USAGES.put(USAGE_NOTIFICATION,                      SUPPRESSIBLE_NOTIFICATION);
        SUPPRESSIBLE_USAGES.put(USAGE_NOTIFICATION_RINGTONE,             SUPPRESSIBLE_CALL);
        SUPPRESSIBLE_USAGES.put(USAGE_NOTIFICATION_COMMUNICATION_REQUEST,SUPPRESSIBLE_CALL);
        SUPPRESSIBLE_USAGES.put(USAGE_NOTIFICATION_COMMUNICATION_INSTANT,SUPPRESSIBLE_NOTIFICATION);
        SUPPRESSIBLE_USAGES.put(USAGE_NOTIFICATION_COMMUNICATION_DELAYED,SUPPRESSIBLE_NOTIFICATION);
        SUPPRESSIBLE_USAGES.put(USAGE_NOTIFICATION_EVENT,                SUPPRESSIBLE_NOTIFICATION);
        SUPPRESSIBLE_USAGES.put(USAGE_ASSISTANCE_ACCESSIBILITY,          SUPPRESSIBLE_NEVER);
        SUPPRESSIBLE_USAGES.put(USAGE_VOICE_COMMUNICATION,               SUPPRESSIBLE_NEVER);
        SUPPRESSIBLE_USAGES.put(USAGE_ALARM,                             SUPPRESSIBLE_ALARM);
        SUPPRESSIBLE_USAGES.put(USAGE_MEDIA,                             SUPPRESSIBLE_MEDIA);
        SUPPRESSIBLE_USAGES.put(USAGE_ASSISTANCE_NAVIGATION_GUIDANCE,    SUPPRESSIBLE_MEDIA);
        SUPPRESSIBLE_USAGES.put(USAGE_GAME,                              SUPPRESSIBLE_MEDIA);
        SUPPRESSIBLE_USAGES.put(USAGE_ASSISTANT,                         SUPPRESSIBLE_MEDIA);
        /** default volume assignment is STREAM_MUSIC, handle unknown usage as media */
        SUPPRESSIBLE_USAGES.put(USAGE_UNKNOWN,                           SUPPRESSIBLE_MEDIA);
        SUPPRESSIBLE_USAGES.put(USAGE_VOICE_COMMUNICATION_SIGNALLING,    SUPPRESSIBLE_SYSTEM);
        SUPPRESSIBLE_USAGES.put(USAGE_ASSISTANCE_SONIFICATION,           SUPPRESSIBLE_SYSTEM);
    }

    
@hide
Array of all usage types exposed in the SDK that applications can use.
/**
     * @hide
     * Array of all usage types exposed in the SDK that applications can use.
     */
    public final static int[] SDK_USAGES = {
            USAGE_UNKNOWN,
            USAGE_MEDIA,
            USAGE_VOICE_COMMUNICATION,
            USAGE_VOICE_COMMUNICATION_SIGNALLING,
            USAGE_ALARM,
            USAGE_NOTIFICATION,
            USAGE_NOTIFICATION_RINGTONE,
            USAGE_NOTIFICATION_COMMUNICATION_REQUEST,
            USAGE_NOTIFICATION_COMMUNICATION_INSTANT,
            USAGE_NOTIFICATION_COMMUNICATION_DELAYED,
            USAGE_NOTIFICATION_EVENT,
            USAGE_ASSISTANCE_ACCESSIBILITY,
            USAGE_ASSISTANCE_NAVIGATION_GUIDANCE,
            USAGE_ASSISTANCE_SONIFICATION,
            USAGE_GAME,
            USAGE_ASSISTANT,
    };

    
Flag defining a behavior where the audibility of the sound will be ensured by the system.

/**
     * Flag defining a behavior where the audibility of the sound will be ensured by the system.
     */
    public final static int FLAG_AUDIBILITY_ENFORCED = 0x1 << 0;
    
@hide
Flag defining a behavior where the playback of the sound is ensured without
degradation only when going to a secure sink.
/**
     * @hide
     * Flag defining a behavior where the playback of the sound is ensured without
     * degradation only when going to a secure sink.
     */
    // FIXME not guaranteed yet
    // TODO  add in FLAG_ALL_PUBLIC when supported and in public API
    public final static int FLAG_SECURE = 0x1 << 1;
    
@hide
Flag to enable when the stream is associated with SCO usage.
Internal use only for dealing with legacy STREAM_BLUETOOTH_SCO
/**
     * @hide
     * Flag to enable when the stream is associated with SCO usage.
     * Internal use only for dealing with legacy STREAM_BLUETOOTH_SCO
     */
    public final static int FLAG_SCO = 0x1 << 2;
    
@hide
Flag defining a behavior where the system ensures that the playback of the sound will
be compatible with its use as a broadcast for surrounding people and/or devices.
Ensures audibility with no or minimal post-processing applied.
/**
     * @hide
     * Flag defining a behavior where the system ensures that the playback of the sound will
     * be compatible with its use as a broadcast for surrounding people and/or devices.
     * Ensures audibility with no or minimal post-processing applied.
     */
    @SystemApi
    public final static int FLAG_BEACON = 0x1 << 3;

    
Flag requesting the use of an output stream supporting hardware A/V synchronization.

/**
     * Flag requesting the use of an output stream supporting hardware A/V synchronization.
     */
    public final static int FLAG_HW_AV_SYNC = 0x1 << 4;

    
@hide
Flag requesting capture from the source used for hardware hotword detection.
To be used with capture preset MediaRecorder.AudioSource.HOTWORD or
MediaRecorder.AudioSource.VOICE_RECOGNITION.
/**
     * @hide
     * Flag requesting capture from the source used for hardware hotword detection.
     * To be used with capture preset MediaRecorder.AudioSource.HOTWORD or
     * MediaRecorder.AudioSource.VOICE_RECOGNITION.
     */
    @SystemApi
    public final static int FLAG_HW_HOTWORD = 0x1 << 5;

    
@hide
Flag requesting audible playback even under limited interruptions.
/**
     * @hide
     * Flag requesting audible playback even under limited interruptions.
     */
    @SystemApi
    public final static int FLAG_BYPASS_INTERRUPTION_POLICY = 0x1 << 6;

    
@hide
Flag requesting audible playback even when the underlying stream is muted.
/**
     * @hide
     * Flag requesting audible playback even when the underlying stream is muted.
     */
    @SystemApi
    public final static int FLAG_BYPASS_MUTE = 0x1 << 7;

    
Flag requesting a low latency path when creating an AudioTrack. When using this flag, the sample rate must match the native sample rate of the device. Effects processing is also unavailable. Note that if this flag is used without specifying a bufferSizeInBytes then the AudioTrack's actual buffer size may be too small. It is recommended that a fairly large buffer should be specified when the AudioTrack is created. Then the actual size can be reduced by calling AudioTrack.setBufferSizeInFrames(int). The buffer size can be optimized by lowering it after each write() call until the audio glitches, which is detected by calling AudioTrack.getUnderrunCount(). Then the buffer size can be increased until there are no glitches. This tuning step should be done while playing silence. This technique provides a compromise between latency and glitch rate. 
Deprecated:Use Builder.setPerformanceMode(int) with AudioTrack.PERFORMANCE_MODE_LOW_LATENCY to control performance.
/**
     * Flag requesting a low latency path when creating an AudioTrack.
     * When using this flag, the sample rate must match the native sample rate
     * of the device. Effects processing is also unavailable.
     *
     * Note that if this flag is used without specifying a bufferSizeInBytes then the
     * AudioTrack's actual buffer size may be too small. It is recommended that a fairly
     * large buffer should be specified when the AudioTrack is created.
     * Then the actual size can be reduced by calling
     * {@link AudioTrack#setBufferSizeInFrames(int)}. The buffer size can be optimized
     * by lowering it after each write() call until the audio glitches, which is detected by calling
     * {@link AudioTrack#getUnderrunCount()}. Then the buffer size can be increased
     * until there are no glitches.
     * This tuning step should be done while playing silence.
     * This technique provides a compromise between latency and glitch rate.
     *
     * @deprecated Use {@link AudioTrack.Builder#setPerformanceMode(int)} with
     * {@link AudioTrack#PERFORMANCE_MODE_LOW_LATENCY} to control performance.
     */
    public final static int FLAG_LOW_LATENCY = 0x1 << 8;

    
@hide Flag requesting a deep buffer path when creating an AudioTrack. A deep buffer path, if available, may consume less power and is suitable for media playback where latency is not a concern. Use Builder.setPerformanceMode(int) with AudioTrack.PERFORMANCE_MODE_POWER_SAVING to enable.
/**
     * @hide
     * Flag requesting a deep buffer path when creating an {@code AudioTrack}.
     *
     * A deep buffer path, if available, may consume less power and is
     * suitable for media playback where latency is not a concern.
     * Use {@link AudioTrack.Builder#setPerformanceMode(int)} with
     * {@link AudioTrack#PERFORMANCE_MODE_POWER_SAVING} to enable.
     */
    public final static int FLAG_DEEP_BUFFER = 0x1 << 9;

    private final static int FLAG_ALL = FLAG_AUDIBILITY_ENFORCED | FLAG_SECURE | FLAG_SCO |
            FLAG_BEACON | FLAG_HW_AV_SYNC | FLAG_HW_HOTWORD | FLAG_BYPASS_INTERRUPTION_POLICY |
            FLAG_BYPASS_MUTE | FLAG_LOW_LATENCY | FLAG_DEEP_BUFFER;
    private final static int FLAG_ALL_PUBLIC = FLAG_AUDIBILITY_ENFORCED |
            FLAG_HW_AV_SYNC | FLAG_LOW_LATENCY;

    private int mUsage = USAGE_UNKNOWN;
    private int mContentType = CONTENT_TYPE_UNKNOWN;
    private int mSource = MediaRecorder.AudioSource.AUDIO_SOURCE_INVALID;
    private int mFlags = 0x0;
    private HashSet<String> mTags;
    private String mFormattedTags;
    private Bundle mBundle; // lazy-initialized, may be null

    private AudioAttributes() {
    }

    
Return the content type.

Returns:one of the values that can be set in Builder.setContentType(int)
/**
     * Return the content type.
     * @return one of the values that can be set in {@link Builder#setContentType(int)}
     */
    public int getContentType() {
        return mContentType;
    }

    
Return the usage.

Returns:one of the values that can be set in Builder.setUsage(int)
/**
     * Return the usage.
     * @return one of the values that can be set in {@link Builder#setUsage(int)}
     */
    public int getUsage() {
        return mUsage;
    }

    
@hide
Return the capture preset.
Returns:one of the values that can be set in Builder.setCapturePreset(int) or a negative value if none has been set.
/**
     * @hide
     * Return the capture preset.
     * @return one of the values that can be set in {@link Builder#setCapturePreset(int)} or a
     *    negative value if none has been set.
     */
    @SystemApi
    public int getCapturePreset() {
        return mSource;
    }

    
Return the flags.

Returns:a combined mask of all flags
/**
     * Return the flags.
     * @return a combined mask of all flags
     */
    public int getFlags() {
        // only return the flags that are public
        return (mFlags & (FLAG_ALL_PUBLIC));
    }

    
@hide
Return all the flags, even the non-public ones.
Internal use only
Returns:a combined mask of all flags
/**
     * @hide
     * Return all the flags, even the non-public ones.
     * Internal use only
     * @return a combined mask of all flags
     */
    @SystemApi
    public int getAllFlags() {
        return (mFlags & FLAG_ALL);
    }

    
@hide
Return the Bundle of data.
Returns:a copy of the Bundle for this instance, may be null.
/**
     * @hide
     * Return the Bundle of data.
     * @return a copy of the Bundle for this instance, may be null.
     */
    @SystemApi
    public Bundle getBundle() {
        if (mBundle == null) {
            return mBundle;
        } else {
            return new Bundle(mBundle);
        }
    }

    
@hide
Return the set of tags.
Returns:a read-only set of all tags stored as strings.
/**
     * @hide
     * Return the set of tags.
     * @return a read-only set of all tags stored as strings.
     */
    public Set<String> getTags() {
        return Collections.unmodifiableSet(mTags);
    }

    
Builder class for AudioAttributes objects. 
 Here is an example where Builder is used to define the AudioAttributes to be used by a new AudioTrack instance:

AudioTrack myTrack = new AudioTrack(
        new AudioAttributes.Builder()
            .setUsage(AudioAttributes.USAGE_MEDIA)
            .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
            .build(),
        myFormat, myBuffSize, AudioTrack.MODE_STREAM, mySession);



By default all types of information (usage, content type, flags) conveyed by an
AudioAttributes instance are set to "unknown". Unknown information will be interpreted as a default value that is dependent on the context of use, for instance a MediaPlayer will use a default usage of AudioAttributes.USAGE_MEDIA. 
/**
     * Builder class for {@link AudioAttributes} objects.
     * <p> Here is an example where <code>Builder</code> is used to define the
     * {@link AudioAttributes} to be used by a new <code>AudioTrack</code> instance:
     *
     * <pre class="prettyprint">
     * AudioTrack myTrack = new AudioTrack(
     *         new AudioAttributes.Builder()
     *             .setUsage(AudioAttributes.USAGE_MEDIA)
     *             .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
     *             .build(),
     *         myFormat, myBuffSize, AudioTrack.MODE_STREAM, mySession);
     * </pre>
     *
     * <p>By default all types of information (usage, content type, flags) conveyed by an
     * <code>AudioAttributes</code> instance are set to "unknown". Unknown information will be
     * interpreted as a default value that is dependent on the context of use, for instance a
     * {@link MediaPlayer} will use a default usage of {@link AudioAttributes#USAGE_MEDIA}.
     */
    public static class Builder {
        private int mUsage = USAGE_UNKNOWN;
        private int mContentType = CONTENT_TYPE_UNKNOWN;
        private int mSource = MediaRecorder.AudioSource.AUDIO_SOURCE_INVALID;
        private int mFlags = 0x0;
        private HashSet<String> mTags = new HashSet<String>();
        private Bundle mBundle;

        
Constructs a new Builder with the defaults. By default, usage and content type are respectively AudioAttributes.USAGE_UNKNOWN and AudioAttributes.CONTENT_TYPE_UNKNOWN, and flags are 0. It is recommended to configure the usage (with setUsage(int)) or deriving attributes from a legacy stream type (with setLegacyStreamType(int)) before calling build() to override any default playback behavior in terms of routing and volume management. 
/**
         * Constructs a new Builder with the defaults.
         * By default, usage and content type are respectively {@link AudioAttributes#USAGE_UNKNOWN}
         * and {@link AudioAttributes#CONTENT_TYPE_UNKNOWN}, and flags are 0. It is recommended to
         * configure the usage (with {@link #setUsage(int)}) or deriving attributes from a legacy
         * stream type (with {@link #setLegacyStreamType(int)}) before calling {@link #build()}
         * to override any default playback behavior in terms of routing and volume management.
         */
        public Builder() {
        }

        
Constructs a new Builder from a given AudioAttributes

Params:
  • aa – the AudioAttributes object whose data will be reused in the new Builder.
/**
         * Constructs a new Builder from a given AudioAttributes
         * @param aa the AudioAttributes object whose data will be reused in the new Builder.
         */
        @SuppressWarnings("unchecked") // for cloning of mTags
        public Builder(AudioAttributes aa) {
            mUsage = aa.mUsage;
            mContentType = aa.mContentType;
            mFlags = aa.mFlags;
            mTags = (HashSet<String>) aa.mTags.clone();
        }

        
Combines all of the attributes that have been set and return a new AudioAttributes object. 
Returns:a new AudioAttributes object
/**
         * Combines all of the attributes that have been set and return a new
         * {@link AudioAttributes} object.
         * @return a new {@link AudioAttributes} object
         */
        @SuppressWarnings("unchecked") // for cloning of mTags
        public AudioAttributes build() {
            AudioAttributes aa = new AudioAttributes();
            aa.mContentType = mContentType;
            aa.mUsage = mUsage;
            aa.mSource = mSource;
            aa.mFlags = mFlags;
            aa.mTags = (HashSet<String>) mTags.clone();
            aa.mFormattedTags = TextUtils.join(";", mTags);
            if (mBundle != null) {
                aa.mBundle = new Bundle(mBundle);
            }
            return aa;
        }

        
Sets the attribute describing what is the intended use of the the audio signal,
such as alarm or ringtone.

Params:
Returns:the same Builder instance.
/**
         * Sets the attribute describing what is the intended use of the the audio signal,
         * such as alarm or ringtone.
         * @param usage one of {@link AudioAttributes#USAGE_UNKNOWN},
         *     {@link AudioAttributes#USAGE_MEDIA},
         *     {@link AudioAttributes#USAGE_VOICE_COMMUNICATION},
         *     {@link AudioAttributes#USAGE_VOICE_COMMUNICATION_SIGNALLING},
         *     {@link AudioAttributes#USAGE_ALARM}, {@link AudioAttributes#USAGE_NOTIFICATION},
         *     {@link AudioAttributes#USAGE_NOTIFICATION_RINGTONE},
         *     {@link AudioAttributes#USAGE_NOTIFICATION_COMMUNICATION_REQUEST},
         *     {@link AudioAttributes#USAGE_NOTIFICATION_COMMUNICATION_INSTANT},
         *     {@link AudioAttributes#USAGE_NOTIFICATION_COMMUNICATION_DELAYED},
         *     {@link AudioAttributes#USAGE_NOTIFICATION_EVENT},
         *     {@link AudioAttributes#USAGE_ASSISTANT},
         *     {@link AudioAttributes#USAGE_ASSISTANCE_ACCESSIBILITY},
         *     {@link AudioAttributes#USAGE_ASSISTANCE_NAVIGATION_GUIDANCE},
         *     {@link AudioAttributes#USAGE_ASSISTANCE_SONIFICATION},
         *     {@link AudioAttributes#USAGE_GAME}.
         * @return the same Builder instance.
         */
        public Builder setUsage(@AttributeUsage int usage) {
            switch (usage) {
                case USAGE_UNKNOWN:
                case USAGE_MEDIA:
                case USAGE_VOICE_COMMUNICATION:
                case USAGE_VOICE_COMMUNICATION_SIGNALLING:
                case USAGE_ALARM:
                case USAGE_NOTIFICATION:
                case USAGE_NOTIFICATION_RINGTONE:
                case USAGE_NOTIFICATION_COMMUNICATION_REQUEST:
                case USAGE_NOTIFICATION_COMMUNICATION_INSTANT:
                case USAGE_NOTIFICATION_COMMUNICATION_DELAYED:
                case USAGE_NOTIFICATION_EVENT:
                case USAGE_ASSISTANCE_ACCESSIBILITY:
                case USAGE_ASSISTANCE_NAVIGATION_GUIDANCE:
                case USAGE_ASSISTANCE_SONIFICATION:
                case USAGE_GAME:
                case USAGE_VIRTUAL_SOURCE:
                case USAGE_ASSISTANT:
                     mUsage = usage;
                     break;
                default:
                     mUsage = USAGE_UNKNOWN;
            }
            return this;
        }

        
Sets the attribute describing the content type of the audio signal, such as speech,
or music.

Params:
Returns:the same Builder instance.
/**
         * Sets the attribute describing the content type of the audio signal, such as speech,
         * or music.
         * @param contentType the content type values, one of
         *     {@link AudioAttributes#CONTENT_TYPE_MOVIE},
         *     {@link AudioAttributes#CONTENT_TYPE_MUSIC},
         *     {@link AudioAttributes#CONTENT_TYPE_SONIFICATION},
         *     {@link AudioAttributes#CONTENT_TYPE_SPEECH},
         *     {@link AudioAttributes#CONTENT_TYPE_UNKNOWN}.
         * @return the same Builder instance.
         */
        public Builder setContentType(@AttributeContentType int contentType) {
            switch (contentType) {
                case CONTENT_TYPE_UNKNOWN:
                case CONTENT_TYPE_MOVIE:
                case CONTENT_TYPE_MUSIC:
                case CONTENT_TYPE_SONIFICATION:
                case CONTENT_TYPE_SPEECH:
                     mContentType = contentType;
                     break;
                default:
                     mUsage = CONTENT_TYPE_UNKNOWN;
            }
            return this;
        }

        
Sets the combination of flags.
This is a bitwise OR with the existing flags.

Params:
Returns:the same Builder instance.
/**
         * Sets the combination of flags.
         *
         * This is a bitwise OR with the existing flags.
         * @param flags a combination of {@link AudioAttributes#FLAG_AUDIBILITY_ENFORCED},
         *    {@link AudioAttributes#FLAG_HW_AV_SYNC}.
         * @return the same Builder instance.
         */
        public Builder setFlags(int flags) {
            flags &= AudioAttributes.FLAG_ALL;
            mFlags |= flags;
            return this;
        }

        
Params:
@hide
Replaces flags.
Returns:the same Builder instance.
/**
         * @hide
         * Replaces flags.
         * @param flags any combination of {@link AudioAttributes#FLAG_ALL}.
         * @return the same Builder instance.
         */
        public Builder replaceFlags(int flags) {
            mFlags = flags & AudioAttributes.FLAG_ALL;
            return this;
        }

        
Params:
  • bundle – a non-null Bundle
@hide
Adds a Bundle of data
Returns:the same builder instance
/**
         * @hide
         * Adds a Bundle of data
         * @param bundle a non-null Bundle
         * @return the same builder instance
         */
        @SystemApi
        public Builder addBundle(@NonNull Bundle bundle) {
            if (bundle == null) {
                throw new IllegalArgumentException("Illegal null bundle");
            }
            if (mBundle == null) {
                mBundle = new Bundle(bundle);
            } else {
                mBundle.putAll(bundle);
            }
            return this;
        }

        
Params:
  • tag – 
@hide
Add a custom tag stored as a string
Returns:the same Builder instance.
/**
         * @hide
         * Add a custom tag stored as a string
         * @param tag
         * @return the same Builder instance.
         */
        public Builder addTag(String tag) {
            mTags.add(tag);
            return this;
        }

        
Sets attributes as inferred from the legacy stream types. Use this method when building an AudioAttributes instance to initialize some of the attributes by information derived from a legacy stream type. 
Params:
Returns:the same Builder instance.
/**
         * Sets attributes as inferred from the legacy stream types.
         * Use this method when building an {@link AudioAttributes} instance to initialize some of
         * the attributes by information derived from a legacy stream type.
         * @param streamType one of {@link AudioManager#STREAM_VOICE_CALL},
         *   {@link AudioManager#STREAM_SYSTEM}, {@link AudioManager#STREAM_RING},
         *   {@link AudioManager#STREAM_MUSIC}, {@link AudioManager#STREAM_ALARM},
         *    or {@link AudioManager#STREAM_NOTIFICATION}.
         * @return the same Builder instance.
         */
        public Builder setLegacyStreamType(int streamType) {
            if (streamType == AudioManager.STREAM_ACCESSIBILITY) {
                throw new IllegalArgumentException("STREAM_ACCESSIBILITY is not a legacy stream "
                        + "type that was used for audio playback");
            }
            return setInternalLegacyStreamType(streamType);
        }

        
Params:
  • streamType – 
@hide
For internal framework use only, enables building from hidden stream types.
Returns:the same Builder instance.
/**
         * @hide
         * For internal framework use only, enables building from hidden stream types.
         * @param streamType
         * @return the same Builder instance.
         */
        public Builder setInternalLegacyStreamType(int streamType) {
            switch(streamType) {
                case AudioSystem.STREAM_VOICE_CALL:
                    mContentType = CONTENT_TYPE_SPEECH;
                    break;
                case AudioSystem.STREAM_SYSTEM_ENFORCED:
                    mFlags |= FLAG_AUDIBILITY_ENFORCED;
                    // intended fall through, attributes in common with STREAM_SYSTEM
                case AudioSystem.STREAM_SYSTEM:
                    mContentType = CONTENT_TYPE_SONIFICATION;
                    break;
                case AudioSystem.STREAM_RING:
                    mContentType = CONTENT_TYPE_SONIFICATION;
                    break;
                case AudioSystem.STREAM_MUSIC:
                    mContentType = CONTENT_TYPE_MUSIC;
                    break;
                case AudioSystem.STREAM_ALARM:
                    mContentType = CONTENT_TYPE_SONIFICATION;
                    break;
                case AudioSystem.STREAM_NOTIFICATION:
                    mContentType = CONTENT_TYPE_SONIFICATION;
                    break;
                case AudioSystem.STREAM_BLUETOOTH_SCO:
                    mContentType = CONTENT_TYPE_SPEECH;
                    mFlags |= FLAG_SCO;
                    break;
                case AudioSystem.STREAM_DTMF:
                    mContentType = CONTENT_TYPE_SONIFICATION;
                    break;
                case AudioSystem.STREAM_TTS:
                    mContentType = CONTENT_TYPE_SONIFICATION;
                    break;
                case AudioSystem.STREAM_ACCESSIBILITY:
                    mContentType = CONTENT_TYPE_SPEECH;
                    break;
                default:
                    Log.e(TAG, "Invalid stream type " + streamType + " for AudioAttributes");
            }
            mUsage = usageForStreamType(streamType);
            return this;
        }

        
Params:
@hide Sets the capture preset. Use this audio attributes configuration method when building an AudioRecord instance with AudioRecord(int, int, int).
Returns:the same Builder instance.
/**
         * @hide
         * Sets the capture preset.
         * Use this audio attributes configuration method when building an {@link AudioRecord}
         * instance with {@link AudioRecord#AudioRecord(AudioAttributes, AudioFormat, int)}.
         * @param preset one of {@link MediaRecorder.AudioSource#DEFAULT},
         *     {@link MediaRecorder.AudioSource#MIC}, {@link MediaRecorder.AudioSource#CAMCORDER},
         *     {@link MediaRecorder.AudioSource#VOICE_RECOGNITION},
         *     {@link MediaRecorder.AudioSource#VOICE_COMMUNICATION} or
         *     {@link MediaRecorder.AudioSource#UNPROCESSED}
         * @return the same Builder instance.
         */
        @SystemApi
        public Builder setCapturePreset(int preset) {
            switch (preset) {
                case MediaRecorder.AudioSource.DEFAULT:
                case MediaRecorder.AudioSource.MIC:
                case MediaRecorder.AudioSource.CAMCORDER:
                case MediaRecorder.AudioSource.VOICE_RECOGNITION:
                case MediaRecorder.AudioSource.VOICE_COMMUNICATION:
                case MediaRecorder.AudioSource.UNPROCESSED:
                    mSource = preset;
                    break;
                default:
                    Log.e(TAG, "Invalid capture preset " + preset + " for AudioAttributes");
            }
            return this;
        }

        
Params:
  • preset – 
@hide Same as setCapturePreset(int) but authorizes the use of HOTWORD, REMOTE_SUBMIX, RADIO_TUNER, VOICE_DOWNLINK, VOICE_UPLINK and VOICE_CALL.
Returns:the same Builder instance.
/**
         * @hide
         * Same as {@link #setCapturePreset(int)} but authorizes the use of HOTWORD,
         * REMOTE_SUBMIX, RADIO_TUNER, VOICE_DOWNLINK, VOICE_UPLINK and VOICE_CALL.
         * @param preset
         * @return the same Builder instance.
         */
        @SystemApi
        public Builder setInternalCapturePreset(int preset) {
            if ((preset == MediaRecorder.AudioSource.HOTWORD)
                    || (preset == MediaRecorder.AudioSource.REMOTE_SUBMIX)
                    || (preset == MediaRecorder.AudioSource.RADIO_TUNER)
                    || (preset == MediaRecorder.AudioSource.VOICE_DOWNLINK)
                    || (preset == MediaRecorder.AudioSource.VOICE_UPLINK)
                    || (preset == MediaRecorder.AudioSource.VOICE_CALL)) {
                mSource = preset;
            } else {
                setCapturePreset(preset);
            }
            return this;
        }
    };

    @Override
    public int describeContents() {
        return 0;
    }

    
@hide
Used to indicate that when parcelling, the tags should be parcelled through the flattened
formatted string, not through the array of strings.
Keep in sync with frameworks/av/media/libmediaplayerservice/MediaPlayerService.cpp
see definition of kAudioAttributesMarshallTagFlattenTags
/**
     * @hide
     * Used to indicate that when parcelling, the tags should be parcelled through the flattened
     * formatted string, not through the array of strings.
     * Keep in sync with frameworks/av/media/libmediaplayerservice/MediaPlayerService.cpp
     * see definition of kAudioAttributesMarshallTagFlattenTags
     */
    public final static int FLATTEN_TAGS = 0x1;

    private final static int ATTR_PARCEL_IS_NULL_BUNDLE = -1977;
    private final static int ATTR_PARCEL_IS_VALID_BUNDLE = 1980;

    
When adding tags for writeToParcel(Parcel, int), add them in the list of flags (| NEW_FLAG)

/**
     * When adding tags for writeToParcel(Parcel, int), add them in the list of flags (| NEW_FLAG)
     */
    private final static int ALL_PARCEL_FLAGS = FLATTEN_TAGS;
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeInt(mUsage);
        dest.writeInt(mContentType);
        dest.writeInt(mSource);
        dest.writeInt(mFlags);
        dest.writeInt(flags & ALL_PARCEL_FLAGS);
        if ((flags & FLATTEN_TAGS) == 0) {
            String[] tagsArray = new String[mTags.size()];
            mTags.toArray(tagsArray);
            dest.writeStringArray(tagsArray);
        } else if ((flags & FLATTEN_TAGS) == FLATTEN_TAGS) {
            dest.writeString(mFormattedTags);
        }
        if (mBundle == null) {
            dest.writeInt(ATTR_PARCEL_IS_NULL_BUNDLE);
        } else {
            dest.writeInt(ATTR_PARCEL_IS_VALID_BUNDLE);
            dest.writeBundle(mBundle);
        }
    }

    private AudioAttributes(Parcel in) {
        mUsage = in.readInt();
        mContentType = in.readInt();
        mSource = in.readInt();
        mFlags = in.readInt();
        boolean hasFlattenedTags = ((in.readInt() & FLATTEN_TAGS) == FLATTEN_TAGS);
        mTags = new HashSet<String>();
        if (hasFlattenedTags) {
            mFormattedTags = new String(in.readString());
            mTags.add(mFormattedTags);
        } else {
            String[] tagsArray = in.readStringArray();
            for (int i = tagsArray.length - 1 ; i >= 0 ; i--) {
                mTags.add(tagsArray[i]);
            }
            mFormattedTags = TextUtils.join(";", mTags);
        }
        switch (in.readInt()) {
            case ATTR_PARCEL_IS_NULL_BUNDLE:
                mBundle = null;
                break;
            case ATTR_PARCEL_IS_VALID_BUNDLE:
                mBundle = new Bundle(in.readBundle());
                break;
            default:
                Log.e(TAG, "Illegal value unmarshalling AudioAttributes, can't initialize bundle");
        }
    }

    public static final Parcelable.Creator<AudioAttributes> CREATOR
            = new Parcelable.Creator<AudioAttributes>() {
        
Rebuilds an AudioAttributes previously stored with writeToParcel().

Params:
  • p – Parcel object to read the AudioAttributes from
Returns:a new AudioAttributes created from the data in the parcel
/**
         * Rebuilds an AudioAttributes previously stored with writeToParcel().
         * @param p Parcel object to read the AudioAttributes from
         * @return a new AudioAttributes created from the data in the parcel
         */
        public AudioAttributes createFromParcel(Parcel p) {
            return new AudioAttributes(p);
        }
        public AudioAttributes[] newArray(int size) {
            return new AudioAttributes[size];
        }
    };

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        AudioAttributes that = (AudioAttributes) o;

        return ((mContentType == that.mContentType)
                && (mFlags == that.mFlags)
                && (mSource == that.mSource)
                && (mUsage == that.mUsage)
                //mFormattedTags is never null due to assignment in Builder or unmarshalling
                && (mFormattedTags.equals(that.mFormattedTags)));
    }

    @Override
    public int hashCode() {
        return Objects.hash(mContentType, mFlags, mSource, mUsage, mFormattedTags, mBundle);
    }

    @Override
    public String toString () {
        return new String("AudioAttributes:"
                + " usage=" + usageToString()
                + " content=" + contentTypeToString()
                + " flags=0x" + Integer.toHexString(mFlags).toUpperCase()
                + " tags=" + mFormattedTags
                + " bundle=" + (mBundle == null ? "null" : mBundle.toString()));
    }

    
@hide
/** @hide */
    public void writeToProto(ProtoOutputStream proto, long fieldId) {
        final long token = proto.start(fieldId);

        proto.write(AudioAttributesProto.USAGE, mUsage);
        proto.write(AudioAttributesProto.CONTENT_TYPE, mContentType);
        proto.write(AudioAttributesProto.FLAGS, mFlags);
        // mFormattedTags is never null due to assignment in Builder or unmarshalling.
        for (String t : mFormattedTags.split(";")) {
            t = t.trim();
            if (t != "") {
                proto.write(AudioAttributesProto.TAGS, t);
            }
        }
        // TODO: is the data in mBundle useful for debugging?

        proto.end(token);
    }

    
@hide
/** @hide */
    public String usageToString() {
        return usageToString(mUsage);
    }

    
@hide
/** @hide */
    public static String usageToString(int usage) {
        switch(usage) {
            case USAGE_UNKNOWN:
                return new String("USAGE_UNKNOWN");
            case USAGE_MEDIA:
                return new String("USAGE_MEDIA");
            case USAGE_VOICE_COMMUNICATION:
                return new String("USAGE_VOICE_COMMUNICATION");
            case USAGE_VOICE_COMMUNICATION_SIGNALLING:
                return new String("USAGE_VOICE_COMMUNICATION_SIGNALLING");
            case USAGE_ALARM:
                return new String("USAGE_ALARM");
            case USAGE_NOTIFICATION:
                return new String("USAGE_NOTIFICATION");
            case USAGE_NOTIFICATION_RINGTONE:
                return new String("USAGE_NOTIFICATION_RINGTONE");
            case USAGE_NOTIFICATION_COMMUNICATION_REQUEST:
                return new String("USAGE_NOTIFICATION_COMMUNICATION_REQUEST");
            case USAGE_NOTIFICATION_COMMUNICATION_INSTANT:
                return new String("USAGE_NOTIFICATION_COMMUNICATION_INSTANT");
            case USAGE_NOTIFICATION_COMMUNICATION_DELAYED:
                return new String("USAGE_NOTIFICATION_COMMUNICATION_DELAYED");
            case USAGE_NOTIFICATION_EVENT:
                return new String("USAGE_NOTIFICATION_EVENT");
            case USAGE_ASSISTANCE_ACCESSIBILITY:
                return new String("USAGE_ASSISTANCE_ACCESSIBILITY");
            case USAGE_ASSISTANCE_NAVIGATION_GUIDANCE:
                return new String("USAGE_ASSISTANCE_NAVIGATION_GUIDANCE");
            case USAGE_ASSISTANCE_SONIFICATION:
                return new String("USAGE_ASSISTANCE_SONIFICATION");
            case USAGE_GAME:
                return new String("USAGE_GAME");
            case USAGE_ASSISTANT:
                return new String("USAGE_ASSISTANT");
            default:
                return new String("unknown usage " + usage);
        }
    }

    
@hide
/** @hide */
    public String contentTypeToString() {
        switch(mContentType) {
            case CONTENT_TYPE_UNKNOWN:
                return new String("CONTENT_TYPE_UNKNOWN");
            case CONTENT_TYPE_SPEECH: return new String("CONTENT_TYPE_SPEECH");
            case CONTENT_TYPE_MUSIC: return new String("CONTENT_TYPE_MUSIC");
            case CONTENT_TYPE_MOVIE: return new String("CONTENT_TYPE_MOVIE");
            case CONTENT_TYPE_SONIFICATION: return new String("CONTENT_TYPE_SONIFICATION");
            default: return new String("unknown content type " + mContentType);
        }
    }

    private static int usageForStreamType(int streamType) {
        switch(streamType) {
            case AudioSystem.STREAM_VOICE_CALL:
                return USAGE_VOICE_COMMUNICATION;
            case AudioSystem.STREAM_SYSTEM_ENFORCED:
            case AudioSystem.STREAM_SYSTEM:
                return USAGE_ASSISTANCE_SONIFICATION;
            case AudioSystem.STREAM_RING:
                return USAGE_NOTIFICATION_RINGTONE;
            case AudioSystem.STREAM_MUSIC:
                return USAGE_MEDIA;
            case AudioSystem.STREAM_ALARM:
                return USAGE_ALARM;
            case AudioSystem.STREAM_NOTIFICATION:
                return USAGE_NOTIFICATION;
            case AudioSystem.STREAM_BLUETOOTH_SCO:
                return USAGE_VOICE_COMMUNICATION;
            case AudioSystem.STREAM_DTMF:
                return USAGE_VOICE_COMMUNICATION_SIGNALLING;
            case AudioSystem.STREAM_ACCESSIBILITY:
                return USAGE_ASSISTANCE_ACCESSIBILITY;
            case AudioSystem.STREAM_TTS:
            default:
                return USAGE_UNKNOWN;
        }
    }

    
Returns the stream type matching this AudioAttributes instance for volume control. Use this method to derive the stream type needed to configure the volume control slider in an Activity with Activity.setVolumeControlStream(int) for playback conducted with these attributes. 
Do not use this method to set the stream type on an audio player object (e.g. AudioTrack, MediaPlayer) as this is deprecated, use AudioAttributes instead. 
Returns:a valid stream type for Activity or stream volume control that matches the attributes, or AudioManager.USE_DEFAULT_STREAM_TYPE if there isn't a direct match. Note that USE_DEFAULT_STREAM_TYPE is not a valid value for AudioManager.setStreamVolume(int, int, int).
/**
     * Returns the stream type matching this {@code AudioAttributes} instance for volume control.
     * Use this method to derive the stream type needed to configure the volume
     * control slider in an {@link android.app.Activity} with
     * {@link android.app.Activity#setVolumeControlStream(int)} for playback conducted with these
     * attributes.
     * <BR>Do not use this method to set the stream type on an audio player object
     * (e.g. {@link AudioTrack}, {@link MediaPlayer}) as this is deprecated,
     * use {@code AudioAttributes} instead.
     * @return a valid stream type for {@code Activity} or stream volume control that matches
     *     the attributes, or {@link AudioManager#USE_DEFAULT_STREAM_TYPE} if there isn't a direct
     *     match. Note that {@code USE_DEFAULT_STREAM_TYPE} is not a valid value
     *     for {@link AudioManager#setStreamVolume(int, int, int)}.
     */
    public int getVolumeControlStream() {
        return toVolumeStreamType(true /*fromGetVolumeControlStream*/, this);
    }

    
Params:
  • aa – non-null AudioAttributes.
@hide
Only use to get which stream type should be used for volume control, NOT for audio playback
(all audio playback APIs are supposed to take AudioAttributes as input parameters)
Returns:a valid stream type for volume control that matches the attributes.
/**
     * @hide
     * Only use to get which stream type should be used for volume control, NOT for audio playback
     * (all audio playback APIs are supposed to take AudioAttributes as input parameters)
     * @param aa non-null AudioAttributes.
     * @return a valid stream type for volume control that matches the attributes.
     */
    public static int toLegacyStreamType(@NonNull AudioAttributes aa) {
        return toVolumeStreamType(false /*fromGetVolumeControlStream*/, aa);
    }

    private static int toVolumeStreamType(boolean fromGetVolumeControlStream, AudioAttributes aa) {
        // flags to stream type mapping
        if ((aa.getFlags() & FLAG_AUDIBILITY_ENFORCED) == FLAG_AUDIBILITY_ENFORCED) {
            return fromGetVolumeControlStream ?
                    AudioSystem.STREAM_SYSTEM : AudioSystem.STREAM_SYSTEM_ENFORCED;
        }
        if ((aa.getFlags() & FLAG_SCO) == FLAG_SCO) {
            return fromGetVolumeControlStream ?
                    AudioSystem.STREAM_VOICE_CALL : AudioSystem.STREAM_BLUETOOTH_SCO;
        }

        // usage to stream type mapping
        switch (aa.getUsage()) {
            case USAGE_MEDIA:
            case USAGE_GAME:
            case USAGE_ASSISTANCE_NAVIGATION_GUIDANCE:
            case USAGE_ASSISTANT:
                return AudioSystem.STREAM_MUSIC;
            case USAGE_ASSISTANCE_SONIFICATION:
                return AudioSystem.STREAM_SYSTEM;
            case USAGE_VOICE_COMMUNICATION:
                return AudioSystem.STREAM_VOICE_CALL;
            case USAGE_VOICE_COMMUNICATION_SIGNALLING:
                return fromGetVolumeControlStream ?
                        AudioSystem.STREAM_VOICE_CALL : AudioSystem.STREAM_DTMF;
            case USAGE_ALARM:
                return AudioSystem.STREAM_ALARM;
            case USAGE_NOTIFICATION_RINGTONE:
                return AudioSystem.STREAM_RING;
            case USAGE_NOTIFICATION:
            case USAGE_NOTIFICATION_COMMUNICATION_REQUEST:
            case USAGE_NOTIFICATION_COMMUNICATION_INSTANT:
            case USAGE_NOTIFICATION_COMMUNICATION_DELAYED:
            case USAGE_NOTIFICATION_EVENT:
                return AudioSystem.STREAM_NOTIFICATION;
            case USAGE_ASSISTANCE_ACCESSIBILITY:
                return AudioSystem.STREAM_ACCESSIBILITY;
            case USAGE_UNKNOWN:
                return AudioSystem.STREAM_MUSIC;
            default:
                if (fromGetVolumeControlStream) {
                    throw new IllegalArgumentException("Unknown usage value " + aa.getUsage() +
                            " in audio attributes");
                } else {
                    return AudioSystem.STREAM_MUSIC;
                }
        }
    }

    
@hide
/** @hide */
    @IntDef({
        USAGE_UNKNOWN,
        USAGE_MEDIA,
        USAGE_VOICE_COMMUNICATION,
        USAGE_VOICE_COMMUNICATION_SIGNALLING,
        USAGE_ALARM,
        USAGE_NOTIFICATION,
        USAGE_NOTIFICATION_RINGTONE,
        USAGE_NOTIFICATION_COMMUNICATION_REQUEST,
        USAGE_NOTIFICATION_COMMUNICATION_INSTANT,
        USAGE_NOTIFICATION_COMMUNICATION_DELAYED,
        USAGE_NOTIFICATION_EVENT,
        USAGE_ASSISTANCE_ACCESSIBILITY,
        USAGE_ASSISTANCE_NAVIGATION_GUIDANCE,
        USAGE_ASSISTANCE_SONIFICATION,
        USAGE_GAME,
        USAGE_ASSISTANT,
    })
    @Retention(RetentionPolicy.SOURCE)
    public @interface AttributeUsage {}

    
@hide
/** @hide */
    @IntDef({
        CONTENT_TYPE_UNKNOWN,
        CONTENT_TYPE_SPEECH,
        CONTENT_TYPE_MUSIC,
        CONTENT_TYPE_MOVIE,
        CONTENT_TYPE_SONIFICATION
    })
    @Retention(RetentionPolicy.SOURCE)
    public @interface AttributeContentType {}
}