/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.media;

import android.annotation.CallbackExecutor;
import android.annotation.FloatRange;
import android.annotation.IntDef;
import android.annotation.IntRange;
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.annotation.RequiresPermission;
import android.annotation.SystemApi;
import android.annotation.TestApi;
import android.app.ActivityThread;
import android.compat.annotation.UnsupportedAppUsage;
import android.content.AttributionSource;
import android.content.AttributionSource.ScopedParcelState;
import android.content.Context;
import android.media.MediaRecorder.Source;
import android.media.audiopolicy.AudioMix;
import android.media.audiopolicy.AudioPolicy;
import android.media.metrics.LogSessionId;
import android.media.projection.MediaProjection;
import android.os.Binder;
import android.os.Build;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.os.Message;
import android.os.Parcel;
import android.os.PersistableBundle;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.util.ArrayMap;
import android.util.Log;
import android.util.Pair;

import com.android.internal.annotations.GuardedBy;
import com.android.internal.util.Preconditions;

import java.io.IOException;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.ref.WeakReference;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.Executor;

/**
 * The AudioRecord class manages the audio resources for Java applications
 * to record audio from the audio input hardware of the platform. This is
 * achieved by "pulling" (reading) the data from the AudioRecord object. The
 * application is responsible for polling the AudioRecord object in time using one of
 * the following three methods:  {@link #read(byte[],int, int)}, {@link #read(short[], int, int)}
 * or {@link #read(ByteBuffer, int)}. The choice of which method to use will be based
 * on the audio data storage format that is the most convenient for the user of AudioRecord.
 * <p>Upon creation, an AudioRecord object initializes its associated audio buffer that it will
 * fill with the new audio data. The size of this buffer, specified during the construction,
 * determines how long an AudioRecord can record before "over-running" data that has not
 * been read yet. Data should be read from the audio hardware in chunks of sizes inferior to
 * the total recording buffer size.</p>
 * <p>
 * Applications creating an AudioRecord instance need
 * {@link android.Manifest.permission#RECORD_AUDIO} or the Builder will throw
 * {@link java.lang.UnsupportedOperationException} on
 * {@link android.media.AudioRecord.Builder#build build()},
 * and the constructor will return an instance in state
 * {@link #STATE_UNINITIALIZED}.</p>
 */
public class AudioRecord implements AudioRouting, MicrophoneDirection,
        AudioRecordingMonitor, AudioRecordingMonitorClient
{
    //---------------------------------------------------------
    // Constants
    //--------------------


    /**
     *  indicates AudioRecord state is not successfully initialized.
     */
    public static final int STATE_UNINITIALIZED = 0;
    /**
     *  indicates AudioRecord state is ready to be used
     */
    public static final int STATE_INITIALIZED   = 1;

    /**
     * indicates AudioRecord recording state is not recording
     */
    public static final int RECORDSTATE_STOPPED = 1;  // matches SL_RECORDSTATE_STOPPED
    /**
     * indicates AudioRecord recording state is recording
     */
    public static final int RECORDSTATE_RECORDING = 3;// matches SL_RECORDSTATE_RECORDING

    /**
     * Denotes a successful operation.
     */
    public  static final int SUCCESS                               = AudioSystem.SUCCESS;
    /**
     * Denotes a generic operation failure.
     */
    public  static final int ERROR                                 = AudioSystem.ERROR;
    /**
     * Denotes a failure due to the use of an invalid value.
     */
    public  static final int ERROR_BAD_VALUE                       = AudioSystem.BAD_VALUE;
    /**
     * Denotes a failure due to the improper use of a method.
     */
    public  static final int ERROR_INVALID_OPERATION               = AudioSystem.INVALID_OPERATION;
    /**
     * An error code indicating that the object reporting it is no longer valid and needs to
     * be recreated.
     */
    public  static final int ERROR_DEAD_OBJECT                     = AudioSystem.DEAD_OBJECT;

    // Error codes:
    // to keep in sync with frameworks/base/core/jni/android_media_AudioRecord.cpp
    private static final int AUDIORECORD_ERROR_SETUP_ZEROFRAMECOUNT      = -16;
    private static final int AUDIORECORD_ERROR_SETUP_INVALIDCHANNELMASK  = -17;
    private static final int AUDIORECORD_ERROR_SETUP_INVALIDFORMAT       = -18;
    private static final int AUDIORECORD_ERROR_SETUP_INVALIDSOURCE       = -19;
    private static final int AUDIORECORD_ERROR_SETUP_NATIVEINITFAILED    = -20;

    // Events:
    // to keep in sync with frameworks/av/include/media/AudioRecord.h
    /**
     * Event id denotes when record head has reached a previously set marker.
     */
    private static final int NATIVE_EVENT_MARKER  = 2;
    /**
     * Event id denotes when previously set update period has elapsed during recording.
     */
    private static final int NATIVE_EVENT_NEW_POS = 3;

    private final static String TAG = "android.media.AudioRecord";

    /** @hide */
    public final static String SUBMIX_FIXED_VOLUME = "fixedVolume";

    /** @hide */
    @IntDef({
        READ_BLOCKING,
        READ_NON_BLOCKING
    })
    @Retention(RetentionPolicy.SOURCE)
    public @interface ReadMode {}

    /**
     * The read mode indicating the read operation will block until all data
     * requested has been read.
     */
    public final static int READ_BLOCKING = 0;

    /**
     * The read mode indicating the read operation will return immediately after
     * reading as much audio data as possible without blocking.
     */
    public final static int READ_NON_BLOCKING = 1;

    //---------------------------------------------------------
    // Used exclusively by native code
    //--------------------
    /**
     * Accessed by native methods: provides access to C++ AudioRecord object
     * Is 0 after release()
     */
    @SuppressWarnings("unused")
    @UnsupportedAppUsage
    private long mNativeRecorderInJavaObj;

    /**
     * Accessed by native methods: provides access to the callback data.
     */
    @SuppressWarnings("unused")
    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
    private long mNativeCallbackCookie;

    /**
     * Accessed by native methods: provides access to the JNIDeviceCallback instance.
     */
    @SuppressWarnings("unused")
    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
    private long mNativeDeviceCallback;


    //---------------------------------------------------------
    // Member variables
    //--------------------
    private AudioPolicy mAudioCapturePolicy;

    /**
     * The audio data sampling rate in Hz.
     * Never {@link AudioFormat#SAMPLE_RATE_UNSPECIFIED}.
     */
    private int mSampleRate; // initialized by all constructors via audioParamCheck()
    /**
     * The number of input audio channels (1 is mono, 2 is stereo)
     */
    private int mChannelCount;
    /**
     * The audio channel position mask
     */
    private int mChannelMask;
    /**
     * The audio channel index mask
     */
    private int mChannelIndexMask;
    /**
     * The encoding of the audio samples.
     * @see AudioFormat#ENCODING_PCM_8BIT
     * @see AudioFormat#ENCODING_PCM_16BIT
     * @see AudioFormat#ENCODING_PCM_FLOAT
     */
    private int mAudioFormat;
    /**
     * Where the audio data is recorded from.
     */
    private int mRecordSource;
    /**
     * Indicates the state of the AudioRecord instance.
     */
    private int mState = STATE_UNINITIALIZED;
    /**
     * Indicates the recording state of the AudioRecord instance.
     */
    private int mRecordingState = RECORDSTATE_STOPPED;
    /**
     * Lock to make sure mRecordingState updates are reflecting the actual state of the object.
     */
    private final Object mRecordingStateLock = new Object();
    /**
     * The listener the AudioRecord notifies when the record position reaches a marker
     * or for periodic updates during the progression of the record head.
     *  @see #setRecordPositionUpdateListener(OnRecordPositionUpdateListener)
     *  @see #setRecordPositionUpdateListener(OnRecordPositionUpdateListener, Handler)
     */
    private OnRecordPositionUpdateListener mPositionListener = null;
    /**
     * Lock to protect position listener updates against event notifications
     */
    private final Object mPositionListenerLock = new Object();
    /**
     * Handler for marker events coming from the native code
     */
    private NativeEventHandler mEventHandler = null;
    /**
     * Looper associated with the thread that creates the AudioRecord instance
     */
    @UnsupportedAppUsage
    private Looper mInitializationLooper = null;
    /**
     * Size of the native audio buffer.
     */
    private int mNativeBufferSizeInBytes = 0;
    /**
     * Audio session ID
     */
    private int mSessionId = AudioManager.AUDIO_SESSION_ID_GENERATE;
    /**
     * AudioAttributes
     */
    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
    private AudioAttributes mAudioAttributes;
    private boolean mIsSubmixFullVolume = false;

    /**
     * The log session id used for metrics.
     * {@link LogSessionId#LOG_SESSION_ID_NONE} here means it is not set.
     */
    @NonNull private LogSessionId mLogSessionId = LogSessionId.LOG_SESSION_ID_NONE;

    //---------------------------------------------------------
    // Constructor, Finalize
    //--------------------
    /**
     * Class constructor.
     * Though some invalid parameters will result in an {@link IllegalArgumentException} exception,
     * other errors do not.  Thus you should call {@link #getState()} immediately after construction
     * to confirm that the object is usable.
     * @param audioSource the recording source.
     *   See {@link MediaRecorder.AudioSource} for the recording source definitions.
     * @param sampleRateInHz the sample rate expressed in Hertz. 44100Hz is currently the only
     *   rate that is guaranteed to work on all devices, but other rates such as 22050,
     *   16000, and 11025 may work on some devices.
     *   {@link AudioFormat#SAMPLE_RATE_UNSPECIFIED} means to use a route-dependent value
     *   which is usually the sample rate of the source.
     *   {@link #getSampleRate()} can be used to retrieve the actual sample rate chosen.
     * @param channelConfig describes the configuration of the audio channels.
     *   See {@link AudioFormat#CHANNEL_IN_MONO} and
     *   {@link AudioFormat#CHANNEL_IN_STEREO}.  {@link AudioFormat#CHANNEL_IN_MONO} is guaranteed
     *   to work on all devices.
     * @param audioFormat the format in which the audio data is to be returned.
     *   See {@link AudioFormat#ENCODING_PCM_8BIT}, {@link AudioFormat#ENCODING_PCM_16BIT},
     *   and {@link AudioFormat#ENCODING_PCM_FLOAT}.
     * @param bufferSizeInBytes the total size (in bytes) of the buffer where audio data is written
     *   to during the recording. New audio data can be read from this buffer in smaller chunks
     *   than this size. See {@link #getMinBufferSize(int, int, int)} to determine the minimum
     *   required buffer size for the successful creation of an AudioRecord instance. Using values
     *   smaller than getMinBufferSize() will result in an initialization failure.
     * @throws java.lang.IllegalArgumentException
     */
    @RequiresPermission(android.Manifest.permission.RECORD_AUDIO)
    public AudioRecord(int audioSource, int sampleRateInHz, int channelConfig, int audioFormat,
            int bufferSizeInBytes)
    throws IllegalArgumentException {
        this((new AudioAttributes.Builder())
                    .setInternalCapturePreset(audioSource)
                    .build(),
                (new AudioFormat.Builder())
                    .setChannelMask(getChannelMaskFromLegacyConfig(channelConfig,
                                        true/*allow legacy configurations*/))
                    .setEncoding(audioFormat)
                    .setSampleRate(sampleRateInHz)
                    .build(),
                bufferSizeInBytes,
                AudioManager.AUDIO_SESSION_ID_GENERATE);
    }

    /**
     * @hide
     * Class constructor with {@link AudioAttributes} and {@link AudioFormat}.
     * @param attributes a non-null {@link AudioAttributes} instance. Use
     *     {@link AudioAttributes.Builder#setCapturePreset(int)} for configuring the audio
     *     source for this instance.
     * @param format a non-null {@link AudioFormat} instance describing the format of the data
     *     that will be recorded through this AudioRecord. See {@link AudioFormat.Builder} for
     *     configuring the audio format parameters such as encoding, channel mask and sample rate.
     * @param bufferSizeInBytes the total size (in bytes) of the buffer where audio data is written
     *   to during the recording. New audio data can be read from this buffer in smaller chunks
     *   than this size. See {@link #getMinBufferSize(int, int, int)} to determine the minimum
     *   required buffer size for the successful creation of an AudioRecord instance. Using values
     *   smaller than getMinBufferSize() will result in an initialization failure.
     * @param sessionId ID of audio session the AudioRecord must be attached to, or
     *   {@link AudioManager#AUDIO_SESSION_ID_GENERATE} if the session isn't known at construction
     *   time. See also {@link AudioManager#generateAudioSessionId()} to obtain a session ID before
     *   construction.
     * @throws IllegalArgumentException
     */
    @SystemApi
    @RequiresPermission(android.Manifest.permission.RECORD_AUDIO)
    public AudioRecord(AudioAttributes attributes, AudioFormat format, int bufferSizeInBytes,
            int sessionId) throws IllegalArgumentException {
        this(attributes, format, bufferSizeInBytes, sessionId,
                ActivityThread.currentApplication(), 0 /*maxSharedAudioHistoryMs*/);
    }

    /**
     * @hide
     * Class constructor with {@link AudioAttributes} and {@link AudioFormat}.
     * @param attributes a non-null {@link AudioAttributes} instance. Use
     *     {@link AudioAttributes.Builder#setCapturePreset(int)} for configuring the audio
     *     source for this instance.
     * @param format a non-null {@link AudioFormat} instance describing the format of the data
     *     that will be recorded through this AudioRecord. See {@link AudioFormat.Builder} for
     *     configuring the audio format parameters such as encoding, channel mask and sample rate.
     * @param bufferSizeInBytes the total size (in bytes) of the buffer where audio data is written
     *   to during the recording. New audio data can be read from this buffer in smaller chunks
     *   than this size. See {@link #getMinBufferSize(int, int, int)} to determine the minimum
     *   required buffer size for the successful creation of an AudioRecord instance. Using values
     *   smaller than getMinBufferSize() will result in an initialization failure.
     * @param sessionId ID of audio session the AudioRecord must be attached to, or
     *   {@link AudioManager#AUDIO_SESSION_ID_GENERATE} if the session isn't known at construction
     *   time. See also {@link AudioManager#generateAudioSessionId()} to obtain a session ID before
     *   construction.
     * @param context An optional context on whose behalf the recoding is performed.
     *
     * @throws IllegalArgumentException
     */
    private AudioRecord(AudioAttributes attributes, AudioFormat format, int bufferSizeInBytes,
            int sessionId, @Nullable Context context,
            int maxSharedAudioHistoryMs) throws IllegalArgumentException {
        mRecordingState = RECORDSTATE_STOPPED;

        if (attributes == null) {
            throw new IllegalArgumentException("Illegal null AudioAttributes");
        }
        if (format == null) {
            throw new IllegalArgumentException("Illegal null AudioFormat");
        }

        // remember which looper is associated with the AudioRecord instanciation
        if ((mInitializationLooper = Looper.myLooper()) == null) {
            mInitializationLooper = Looper.getMainLooper();
        }

        // is this AudioRecord using REMOTE_SUBMIX at full volume?
        if (attributes.getCapturePreset() == MediaRecorder.AudioSource.REMOTE_SUBMIX) {
            final AudioAttributes.Builder filteredAttr = new AudioAttributes.Builder();
            final Iterator<String> tagsIter = attributes.getTags().iterator();
            while (tagsIter.hasNext()) {
                final String tag = tagsIter.next();
                if (tag.equalsIgnoreCase(SUBMIX_FIXED_VOLUME)) {
                    mIsSubmixFullVolume = true;
                    Log.v(TAG, "Will record from REMOTE_SUBMIX at full fixed volume");
                } else { // SUBMIX_FIXED_VOLUME: is not to be propagated to the native layers
                    filteredAttr.addTag(tag);
                }
            }
            filteredAttr.setInternalCapturePreset(attributes.getCapturePreset());
            mAudioAttributes = filteredAttr.build();
        } else {
            mAudioAttributes = attributes;
        }

        int rate = format.getSampleRate();
        if (rate == AudioFormat.SAMPLE_RATE_UNSPECIFIED) {
            rate = 0;
        }

        int encoding = AudioFormat.ENCODING_DEFAULT;
        if ((format.getPropertySetMask() & AudioFormat.AUDIO_FORMAT_HAS_PROPERTY_ENCODING) != 0)
        {
            encoding = format.getEncoding();
        }

        audioParamCheck(attributes.getCapturePreset(), rate, encoding);

        if ((format.getPropertySetMask()
                & AudioFormat.AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_INDEX_MASK) != 0) {
            mChannelIndexMask = format.getChannelIndexMask();
            mChannelCount = format.getChannelCount();
        }
        if ((format.getPropertySetMask()
                & AudioFormat.AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_MASK) != 0) {
            mChannelMask = getChannelMaskFromLegacyConfig(format.getChannelMask(), false);
            mChannelCount = format.getChannelCount();
        } else if (mChannelIndexMask == 0) {
            mChannelMask = getChannelMaskFromLegacyConfig(AudioFormat.CHANNEL_IN_DEFAULT, false);
            mChannelCount =  AudioFormat.channelCountFromInChannelMask(mChannelMask);
        }

        audioBuffSizeCheck(bufferSizeInBytes);

        AttributionSource attributionSource = (context != null)
                ? context.getAttributionSource() : AttributionSource.myAttributionSource();
        if (attributionSource.getPackageName() == null) {
            // Command line utility
            attributionSource = attributionSource.withPackageName("uid:" + Binder.getCallingUid());
        }

        int[] sampleRate = new int[] {mSampleRate};
        int[] session = new int[1];
        session[0] = sessionId;

        //TODO: update native initialization when information about hardware init failure
        //      due to capture device already open is available.
        try (ScopedParcelState attributionSourceState = attributionSource.asScopedParcelState()) {
            int initResult = native_setup(new WeakReference<AudioRecord>(this), mAudioAttributes,
                    sampleRate, mChannelMask, mChannelIndexMask, mAudioFormat,
                    mNativeBufferSizeInBytes, session, attributionSourceState.getParcel(),
                    0 /*nativeRecordInJavaObj*/, maxSharedAudioHistoryMs);
            if (initResult != SUCCESS) {
                loge("Error code " + initResult + " when initializing native AudioRecord object.");
                return; // with mState == STATE_UNINITIALIZED
            }
        }

        mSampleRate = sampleRate[0];
        mSessionId = session[0];

        mState = STATE_INITIALIZED;
    }

    /**
     * A constructor which explicitly connects a Native (C++) AudioRecord. For use by
     * the AudioRecordRoutingProxy subclass.
     * @param nativeRecordInJavaObj A C/C++ pointer to a native AudioRecord
     * (associated with an OpenSL ES recorder). Note: the caller must ensure a correct
     * value here as no error checking is or can be done.
     */
    /*package*/ AudioRecord(long nativeRecordInJavaObj) {
        mNativeRecorderInJavaObj = 0;
        mNativeCallbackCookie = 0;
        mNativeDeviceCallback = 0;

        // other initialization...
        if (nativeRecordInJavaObj != 0) {
            deferred_connect(nativeRecordInJavaObj);
        } else {
            mState = STATE_UNINITIALIZED;
        }
    }

    /**
     * Sets an {@link AudioPolicy} to automatically unregister when the record is released.
     *
     * <p>This is to prevent users of the audio capture API from having to manually unregister the
     * policy that was used to create the record.
     */
    private void unregisterAudioPolicyOnRelease(AudioPolicy audioPolicy) {
        mAudioCapturePolicy = audioPolicy;
    }

    /**
     * @hide
     */
    /* package */ void deferred_connect(long  nativeRecordInJavaObj) {
        if (mState != STATE_INITIALIZED) {
            int[] session = {0};
            int[] rates = {0};
            //TODO: update native initialization when information about hardware init failure
            //      due to capture device already open is available.
            // Note that for this native_setup, we are providing an already created/initialized
            // *Native* AudioRecord, so the attributes parameters to native_setup() are ignored.
            final int initResult;
            try (ScopedParcelState attributionSourceState = AttributionSource.myAttributionSource()
                    .asScopedParcelState()) {
                initResult = native_setup(new WeakReference<>(this),
                        null /*mAudioAttributes*/,
                        rates /*mSampleRates*/,
                        0 /*mChannelMask*/,
                        0 /*mChannelIndexMask*/,
                        0 /*mAudioFormat*/,
                        0 /*mNativeBufferSizeInBytes*/,
                        session,
                        attributionSourceState.getParcel(),
                        nativeRecordInJavaObj,
                        0);
            }
            if (initResult != SUCCESS) {
                loge("Error code "+initResult+" when initializing native AudioRecord object.");
                return; // with mState == STATE_UNINITIALIZED
            }

            mSessionId = session[0];

            mState = STATE_INITIALIZED;
        }
    }

    /** @hide */
    public AudioAttributes getAudioAttributes() {
        return mAudioAttributes;
    }

    /**
     * Builder class for {@link AudioRecord} objects.
     * Use this class to configure and create an <code>AudioRecord</code> instance. By setting the
     * recording source and audio format parameters, you indicate which of
     * those vary from the default behavior on the device.
     * <p> Here is an example where <code>Builder</code> is used to specify all {@link AudioFormat}
     * parameters, to be used by a new <code>AudioRecord</code> instance:
     *
     * <pre class="prettyprint">
     * AudioRecord recorder = new AudioRecord.Builder()
     *         .setAudioSource(MediaRecorder.AudioSource.VOICE_COMMUNICATION)
     *         .setAudioFormat(new AudioFormat.Builder()
     *                 .setEncoding(AudioFormat.ENCODING_PCM_16BIT)
     *                 .setSampleRate(32000)
     *                 .setChannelMask(AudioFormat.CHANNEL_IN_MONO)
     *                 .build())
     *         .setBufferSizeInBytes(2*minBuffSize)
     *         .build();
     * </pre>
     * <p>
     * If the audio source is not set with {@link #setAudioSource(int)},
     * {@link MediaRecorder.AudioSource#DEFAULT} is used.
     * <br>If the audio format is not specified or is incomplete, its channel configuration will be
     * {@link AudioFormat#CHANNEL_IN_MONO}, and the encoding will be
     * {@link AudioFormat#ENCODING_PCM_16BIT}.
     * The sample rate will depend on the device actually selected for capture and can be queried
     * with {@link #getSampleRate()} method.
     * <br>If the buffer size is not specified with {@link #setBufferSizeInBytes(int)},
     * the minimum buffer size for the source is used.
     */
    public static class Builder {

        private static final String ERROR_MESSAGE_SOURCE_MISMATCH =
                "Cannot both set audio source and set playback capture config";

        private AudioPlaybackCaptureConfiguration mAudioPlaybackCaptureConfiguration;
        private AudioAttributes mAttributes;
        private AudioFormat mFormat;
        private Context mContext;
        private int mBufferSizeInBytes;
        private int mSessionId = AudioManager.AUDIO_SESSION_ID_GENERATE;
        private int mPrivacySensitive = PRIVACY_SENSITIVE_DEFAULT;
        private int mMaxSharedAudioHistoryMs = 0;
        private static final int PRIVACY_SENSITIVE_DEFAULT = -1;
        private static final int PRIVACY_SENSITIVE_DISABLED = 0;
        private static final int PRIVACY_SENSITIVE_ENABLED = 1;

        /**
         * Constructs a new Builder with the default values as described above.
         */
        public Builder() {
        }

        /**
         * @param source the audio source.
         * See {@link MediaRecorder.AudioSource} for the supported audio source definitions.
         * @return the same Builder instance.
         * @throws IllegalArgumentException
         */
        public Builder setAudioSource(@Source int source) throws IllegalArgumentException {
            Preconditions.checkState(
                    mAudioPlaybackCaptureConfiguration == null,
                    ERROR_MESSAGE_SOURCE_MISMATCH);
            if ( (source < MediaRecorder.AudioSource.DEFAULT) ||
                    (source > MediaRecorder.getAudioSourceMax()) ) {
                throw new IllegalArgumentException("Invalid audio source " + source);
            }
            mAttributes = new AudioAttributes.Builder()
                    .setInternalCapturePreset(source)
                    .build();
            return this;
        }

        /**
         * Sets the context the record belongs to. This context will be used to pull information,
         * such as {@link android.content.AttributionSource}, which will be associated with
         * the AudioRecord. However, the context itself will not be retained by the AudioRecord.
         * @param context a non-null {@link Context} instance
         * @return the same Builder instance.
         */
        public @NonNull Builder setContext(@NonNull Context context) {
            Objects.requireNonNull(context);
            // keep reference, we only copy the data when building
            mContext = context;
            return this;
        }

        /**
         * @hide
         * To be only used by system components. Allows specifying non-public capture presets
         * @param attributes a non-null {@link AudioAttributes} instance that contains the capture
         *     preset to be used.
         * @return the same Builder instance.
         * @throws IllegalArgumentException
         */
        @SystemApi
        public Builder setAudioAttributes(@NonNull AudioAttributes attributes)
                throws IllegalArgumentException {
            if (attributes == null) {
                throw new IllegalArgumentException("Illegal null AudioAttributes argument");
            }
            if (attributes.getCapturePreset() == MediaRecorder.AudioSource.AUDIO_SOURCE_INVALID) {
                throw new IllegalArgumentException(
                        "No valid capture preset in AudioAttributes argument");
            }
            // keep reference, we only copy the data when building
            mAttributes = attributes;
            return this;
        }

        /**
         * Sets the format of the audio data to be captured.
         * @param format a non-null {@link AudioFormat} instance
         * @return the same Builder instance.
         * @throws IllegalArgumentException
         */
        public Builder setAudioFormat(@NonNull AudioFormat format) throws IllegalArgumentException {
            if (format == null) {
                throw new IllegalArgumentException("Illegal null AudioFormat argument");
            }
            // keep reference, we only copy the data when building
            mFormat = format;
            return this;
        }

        /**
         * Sets the total size (in bytes) of the buffer where audio data is written
         * during the recording. New audio data can be read from this buffer in smaller chunks
         * than this size. See {@link #getMinBufferSize(int, int, int)} to determine the minimum
         * required buffer size for the successful creation of an AudioRecord instance.
         * Since bufferSizeInBytes may be internally increased to accommodate the source
         * requirements, use {@link #getBufferSizeInFrames()} to determine the actual buffer size
         * in frames.
         * @param bufferSizeInBytes a value strictly greater than 0
         * @return the same Builder instance.
         * @throws IllegalArgumentException
         */
        public Builder setBufferSizeInBytes(int bufferSizeInBytes) throws IllegalArgumentException {
            if (bufferSizeInBytes <= 0) {
                throw new IllegalArgumentException("Invalid buffer size " + bufferSizeInBytes);
            }
            mBufferSizeInBytes = bufferSizeInBytes;
            return this;
        }

        /**
         * Sets the {@link AudioRecord} to record audio played by other apps.
         *
         * @param config Defines what apps to record audio from (i.e., via either their uid or
         *               the type of audio).
         * @throws IllegalStateException if called in conjunction with {@link #setAudioSource(int)}.
         * @throws NullPointerException if {@code config} is null.
         */
        public @NonNull Builder setAudioPlaybackCaptureConfig(
                @NonNull AudioPlaybackCaptureConfiguration config) {
            Preconditions.checkNotNull(
                    config, "Illegal null AudioPlaybackCaptureConfiguration argument");
            Preconditions.checkState(
                    mAttributes == null,
                    ERROR_MESSAGE_SOURCE_MISMATCH);
            mAudioPlaybackCaptureConfiguration = config;
            return this;
        }

        /**
         * Indicates that this capture request is privacy sensitive and that
         * any concurrent capture is not permitted.
         * <p>
         * The default is not privacy sensitive except when the audio source set with
         * {@link #setAudioSource(int)} is {@link MediaRecorder.AudioSource#VOICE_COMMUNICATION} or
         * {@link MediaRecorder.AudioSource#CAMCORDER}.
         * <p>
         * Always takes precedence over default from audio source when set explicitly.
         * <p>
         * Using this API is only permitted when the audio source is one of:
         * <ul>
         * <li>{@link MediaRecorder.AudioSource#MIC}</li>
         * <li>{@link MediaRecorder.AudioSource#CAMCORDER}</li>
         * <li>{@link MediaRecorder.AudioSource#VOICE_RECOGNITION}</li>
         * <li>{@link MediaRecorder.AudioSource#VOICE_COMMUNICATION}</li>
         * <li>{@link MediaRecorder.AudioSource#UNPROCESSED}</li>
         * <li>{@link MediaRecorder.AudioSource#VOICE_PERFORMANCE}</li>
         * </ul>
         * Invoking {@link #build()} will throw an UnsupportedOperationException if this
         * condition is not met.
         * @param privacySensitive True if capture from this AudioRecord must be marked as privacy
         * sensitive, false otherwise.
         */
        public @NonNull Builder setPrivacySensitive(boolean privacySensitive) {
            mPrivacySensitive =
                privacySensitive ? PRIVACY_SENSITIVE_ENABLED : PRIVACY_SENSITIVE_DISABLED;
            return this;
        }

        /**
         * @hide
         * To be only used by system components.
         * @param sessionId ID of audio session the AudioRecord must be attached to, or
         *     {@link AudioManager#AUDIO_SESSION_ID_GENERATE} if the session isn't known at
         *     construction time.
         * @return the same Builder instance.
         * @throws IllegalArgumentException
         */
        @SystemApi
        public Builder setSessionId(int sessionId) throws IllegalArgumentException {
            if (sessionId < 0) {
                throw new IllegalArgumentException("Invalid session ID " + sessionId);
            }
            // Do not override a session ID previously set with setSharedAudioEvent()
            if (mSessionId == AudioManager.AUDIO_SESSION_ID_GENERATE) {
                mSessionId = sessionId;
            } else {
                Log.e(TAG, "setSessionId() called twice or after setSharedAudioEvent()");
            }
            return this;
        }

        private @NonNull AudioRecord buildAudioPlaybackCaptureRecord() {
            AudioMix audioMix = mAudioPlaybackCaptureConfiguration.createAudioMix(mFormat);
            MediaProjection projection = mAudioPlaybackCaptureConfiguration.getMediaProjection();
            AudioPolicy audioPolicy = new AudioPolicy.Builder(/*context=*/ null)
                    .setMediaProjection(projection)
                    .addMix(audioMix).build();

            int error = AudioManager.registerAudioPolicyStatic(audioPolicy);
            if (error != 0) {
                throw new UnsupportedOperationException("Error: could not register audio policy");
            }

            AudioRecord record = audioPolicy.createAudioRecordSink(audioMix);
            if (record == null) {
                throw new UnsupportedOperationException("Cannot create AudioRecord");
            }
            record.unregisterAudioPolicyOnRelease(audioPolicy);
            return record;
        }

        /**
         * @hide
         * Specifies the maximum duration in the past of the this AudioRecord's capture buffer
         * that can be shared with another app by calling
         * {@link AudioRecord#shareAudioHistory(String, long)}.
         * @param maxSharedAudioHistoryMillis the maximum duration that will be available
         *                                    in milliseconds.
         * @return the same Builder instance.
         * @throws IllegalArgumentException
         *
         */
        @SystemApi
        @RequiresPermission(android.Manifest.permission.CAPTURE_AUDIO_HOTWORD)
        public @NonNull Builder setMaxSharedAudioHistoryMillis(long maxSharedAudioHistoryMillis)
                throws IllegalArgumentException {
            if (maxSharedAudioHistoryMillis <= 0
                    || maxSharedAudioHistoryMillis > MAX_SHARED_AUDIO_HISTORY_MS) {
                throw new IllegalArgumentException("Illegal maxSharedAudioHistoryMillis argument");
            }
            mMaxSharedAudioHistoryMs = (int) maxSharedAudioHistoryMillis;
            return this;
        }

        /**
         * @hide
         * Indicates that this AudioRecord will use the audio history shared by another app's
         * AudioRecord. See {@link AudioRecord#shareAudioHistory(String, long)}.
         * The audio session ID set with {@link AudioRecord.Builder#setSessionId(int)} will be
         * ignored if this method is used.
         * @param event The {@link MediaSyncEvent} provided by the app sharing its audio history
         *              with this AudioRecord.
         * @return the same Builder instance.
         * @throws IllegalArgumentException
         */
        @SystemApi
        public @NonNull Builder setSharedAudioEvent(@NonNull MediaSyncEvent event)
                throws IllegalArgumentException {
            Objects.requireNonNull(event);
            if (event.getType() != MediaSyncEvent.SYNC_EVENT_SHARE_AUDIO_HISTORY) {
                throw new IllegalArgumentException(
                        "Invalid event type " + event.getType());
            }
            if (event.getAudioSessionId() == AudioSystem.AUDIO_SESSION_ALLOCATE) {
                throw new IllegalArgumentException(
                        "Invalid session ID " + event.getAudioSessionId());
            }
            // This prevails over a session ID set with setSessionId()
            mSessionId = event.getAudioSessionId();
            return this;
        }

        /**
         * @return a new {@link AudioRecord} instance successfully initialized with all
         *     the parameters set on this <code>Builder</code>.
         * @throws UnsupportedOperationException if the parameters set on the <code>Builder</code>
         *     were incompatible, or if they are not supported by the device,
         *     or if the device was not available.
         */
        @RequiresPermission(android.Manifest.permission.RECORD_AUDIO)
        public AudioRecord build() throws UnsupportedOperationException {
            if (mAudioPlaybackCaptureConfiguration != null) {
                return buildAudioPlaybackCaptureRecord();
            }

            if (mFormat == null) {
                mFormat = new AudioFormat.Builder()
                        .setEncoding(AudioFormat.ENCODING_PCM_16BIT)
                        .setChannelMask(AudioFormat.CHANNEL_IN_MONO)
                        .build();
            } else {
                if (mFormat.getEncoding() == AudioFormat.ENCODING_INVALID) {
                    mFormat = new AudioFormat.Builder(mFormat)
                            .setEncoding(AudioFormat.ENCODING_PCM_16BIT)
                            .build();
                }
                if (mFormat.getChannelMask() == AudioFormat.CHANNEL_INVALID
                        && mFormat.getChannelIndexMask() == AudioFormat.CHANNEL_INVALID) {
                    mFormat = new AudioFormat.Builder(mFormat)
                            .setChannelMask(AudioFormat.CHANNEL_IN_MONO)
                            .build();
                }
            }
            if (mAttributes == null) {
                mAttributes = new AudioAttributes.Builder()
                        .setInternalCapturePreset(MediaRecorder.AudioSource.DEFAULT)
                        .build();
            }

            // If mPrivacySensitive is default, the privacy flag is already set
            // according to audio source in audio attributes.
            if (mPrivacySensitive != PRIVACY_SENSITIVE_DEFAULT) {
                int source = mAttributes.getCapturePreset();
                if (source == MediaRecorder.AudioSource.REMOTE_SUBMIX
                        || source == MediaRecorder.AudioSource.RADIO_TUNER
                        || source == MediaRecorder.AudioSource.VOICE_DOWNLINK
                        || source == MediaRecorder.AudioSource.VOICE_UPLINK
                        || source == MediaRecorder.AudioSource.VOICE_CALL
                        || source == MediaRecorder.AudioSource.ECHO_REFERENCE) {
                    throw new UnsupportedOperationException(
                            "Cannot request private capture with source: " + source);
                }

                mAttributes = new AudioAttributes.Builder(mAttributes)
                        .setInternalCapturePreset(source)
                        .setPrivacySensitive(mPrivacySensitive == PRIVACY_SENSITIVE_ENABLED)
                        .build();
            }

            try {
                // If the buffer size is not specified,
                // use a single frame for the buffer size and let the
                // native code figure out the minimum buffer size.
                if (mBufferSizeInBytes == 0) {
                    mBufferSizeInBytes = mFormat.getChannelCount()
                            * mFormat.getBytesPerSample(mFormat.getEncoding());
                }
                final AudioRecord record = new AudioRecord(
                        mAttributes, mFormat, mBufferSizeInBytes, mSessionId, mContext,
                                    mMaxSharedAudioHistoryMs);
                if (record.getState() == STATE_UNINITIALIZED) {
                    // release is not necessary
                    throw new UnsupportedOperationException("Cannot create AudioRecord");
                }
                return record;
            } catch (IllegalArgumentException e) {
                throw new UnsupportedOperationException(e.getMessage());
            }
        }
    }

    // Convenience method for the constructor's parameter checks.
    // This, getChannelMaskFromLegacyConfig and audioBuffSizeCheck are where constructor
    // IllegalArgumentException-s are thrown
    private static int getChannelMaskFromLegacyConfig(int inChannelConfig,
            boolean allowLegacyConfig) {
        int mask;
        switch (inChannelConfig) {
        case AudioFormat.CHANNEL_IN_DEFAULT: // AudioFormat.CHANNEL_CONFIGURATION_DEFAULT
        case AudioFormat.CHANNEL_IN_MONO:
        case AudioFormat.CHANNEL_CONFIGURATION_MONO:
            mask = AudioFormat.CHANNEL_IN_MONO;
            break;
        case AudioFormat.CHANNEL_IN_STEREO:
        case AudioFormat.CHANNEL_CONFIGURATION_STEREO:
            mask = AudioFormat.CHANNEL_IN_STEREO;
            break;
        case (AudioFormat.CHANNEL_IN_FRONT | AudioFormat.CHANNEL_IN_BACK):
            mask = inChannelConfig;
            break;
        default:
            throw new IllegalArgumentException("Unsupported channel configuration.");
        }

        if (!allowLegacyConfig && ((inChannelConfig == AudioFormat.CHANNEL_CONFIGURATION_MONO)
                || (inChannelConfig == AudioFormat.CHANNEL_CONFIGURATION_STEREO))) {
            // only happens with the constructor that uses AudioAttributes and AudioFormat
            throw new IllegalArgumentException("Unsupported deprecated configuration.");
        }

        return mask;
    }

    // postconditions:
    //    mRecordSource is valid
    //    mAudioFormat is valid
    //    mSampleRate is valid
    private void audioParamCheck(int audioSource, int sampleRateInHz, int audioFormat)
            throws IllegalArgumentException {

        //--------------
        // audio source
        if ( (audioSource < MediaRecorder.AudioSource.DEFAULT) ||
             ((audioSource > MediaRecorder.getAudioSourceMax()) &&
              (audioSource != MediaRecorder.AudioSource.RADIO_TUNER) &&
              (audioSource != MediaRecorder.AudioSource.ECHO_REFERENCE) &&
              (audioSource != MediaRecorder.AudioSource.HOTWORD)) )  {
            throw new IllegalArgumentException("Invalid audio source " + audioSource);
        }
        mRecordSource = audioSource;

        //--------------
        // sample rate
        if ((sampleRateInHz < AudioFormat.SAMPLE_RATE_HZ_MIN ||
                sampleRateInHz > AudioFormat.SAMPLE_RATE_HZ_MAX) &&
                sampleRateInHz != AudioFormat.SAMPLE_RATE_UNSPECIFIED) {
            throw new IllegalArgumentException(sampleRateInHz
                    + "Hz is not a supported sample rate.");
        }
        mSampleRate = sampleRateInHz;

        //--------------
        // audio format
        switch (audioFormat) {
            case AudioFormat.ENCODING_DEFAULT:
                mAudioFormat = AudioFormat.ENCODING_PCM_16BIT;
                break;
            case AudioFormat.ENCODING_PCM_24BIT_PACKED:
            case AudioFormat.ENCODING_PCM_32BIT:
            case AudioFormat.ENCODING_PCM_FLOAT:
            case AudioFormat.ENCODING_PCM_16BIT:
            case AudioFormat.ENCODING_PCM_8BIT:
                mAudioFormat = audioFormat;
                break;
            default:
                throw new IllegalArgumentException("Unsupported sample encoding " + audioFormat
                        + ". Should be ENCODING_PCM_8BIT, ENCODING_PCM_16BIT,"
                        + " ENCODING_PCM_24BIT_PACKED, ENCODING_PCM_32BIT,"
                        + " or ENCODING_PCM_FLOAT.");
        }
    }


    // Convenience method for the contructor's audio buffer size check.
    // preconditions:
    //    mChannelCount is valid
    //    mAudioFormat is AudioFormat.ENCODING_PCM_8BIT, AudioFormat.ENCODING_PCM_16BIT,
    //                 or AudioFormat.ENCODING_PCM_FLOAT
    // postcondition:
    //    mNativeBufferSizeInBytes is valid (multiple of frame size, positive)
    private void audioBuffSizeCheck(int audioBufferSize) throws IllegalArgumentException {
        // NB: this section is only valid with PCM data.
        // To update when supporting compressed formats
        int frameSizeInBytes = mChannelCount
            * (AudioFormat.getBytesPerSample(mAudioFormat));
        if ((audioBufferSize % frameSizeInBytes != 0) || (audioBufferSize < 1)) {
            throw new IllegalArgumentException("Invalid audio buffer size " + audioBufferSize
                    + " (frame size " + frameSizeInBytes + ")");
        }

        mNativeBufferSizeInBytes = audioBufferSize;
    }



    /**
     * Releases the native AudioRecord resources.
     * The object can no longer be used and the reference should be set to null
     * after a call to release()
     */
    public void release() {
        try {
            stop();
        } catch(IllegalStateException ise) {
            // don't raise an exception, we're releasing the resources.
        }
        if (mAudioCapturePolicy != null) {
            AudioManager.unregisterAudioPolicyAsyncStatic(mAudioCapturePolicy);
            mAudioCapturePolicy = null;
        }
        native_release();
        mState = STATE_UNINITIALIZED;
    }


    @Override
    protected void finalize() {
        // will cause stop() to be called, and if appropriate, will handle fixed volume recording
        release();
    }


    //--------------------------------------------------------------------------
    // Getters
    //--------------------
    /**
     * Returns the configured audio sink sample rate in Hz.
     * The sink sample rate never changes after construction.
     * If the constructor had a specific sample rate, then the sink sample rate is that value.
     * If the constructor had {@link AudioFormat#SAMPLE_RATE_UNSPECIFIED},
     * then the sink sample rate is a route-dependent default value based on the source [sic].
     */
    public int getSampleRate() {
        return mSampleRate;
    }

    /**
     * Returns the audio recording source.
     * @see MediaRecorder.AudioSource
     */
    public int getAudioSource() {
        return mRecordSource;
    }

    /**
     * Returns the configured audio data encoding. See {@link AudioFormat#ENCODING_PCM_8BIT},
     * {@link AudioFormat#ENCODING_PCM_16BIT}, and {@link AudioFormat#ENCODING_PCM_FLOAT}.
     */
    public int getAudioFormat() {
        return mAudioFormat;
    }

    /**
     * Returns the configured channel position mask.
     * <p> See {@link AudioFormat#CHANNEL_IN_MONO}
     * and {@link AudioFormat#CHANNEL_IN_STEREO}.
     * This method may return {@link AudioFormat#CHANNEL_INVALID} if
     * a channel index mask is used.
     * Consider {@link #getFormat()} instead, to obtain an {@link AudioFormat},
     * which contains both the channel position mask and the channel index mask.
     */
    public int getChannelConfiguration() {
        return mChannelMask;
    }

    /**
     * Returns the configured <code>AudioRecord</code> format.
     * @return an {@link AudioFormat} containing the
     * <code>AudioRecord</code> parameters at the time of configuration.
     */
    public @NonNull AudioFormat getFormat() {
        AudioFormat.Builder builder = new AudioFormat.Builder()
            .setSampleRate(mSampleRate)
            .setEncoding(mAudioFormat);
        if (mChannelMask != AudioFormat.CHANNEL_INVALID) {
            builder.setChannelMask(mChannelMask);
        }
        if (mChannelIndexMask != AudioFormat.CHANNEL_INVALID  /* 0 */) {
            builder.setChannelIndexMask(mChannelIndexMask);
        }
        return builder.build();
    }

    /**
     * Returns the configured number of channels.
     */
    public int getChannelCount() {
        return mChannelCount;
    }

    /**
     * Returns the state of the AudioRecord instance. This is useful after the
     * AudioRecord instance has been created to check if it was initialized
     * properly. This ensures that the appropriate hardware resources have been
     * acquired.
     * @see AudioRecord#STATE_INITIALIZED
     * @see AudioRecord#STATE_UNINITIALIZED
     */
    public int getState() {
        return mState;
    }

    /**
     * Returns…