xref: /frameworks/base/core/java/android/hardware/camera2/CaptureRequest.java

/*
 * Copyright (C) 2013 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.hardware.camera2;

import android.hardware.camera2.impl.CameraMetadataNative;
import android.os.Parcel;
import android.os.Parcelable;
import android.view.Surface;

import java.util.HashSet;
import java.util.Objects;


/**
 * <p>An immutable package of settings and outputs needed to capture a single
 * image from the camera device.</p>
 *
 * <p>Contains the configuration for the capture hardware (sensor, lens, flash),
 * the processing pipeline, the control algorithms, and the output buffers. Also
 * contains the list of target Surfaces to send image data to for this
 * capture.</p>
 *
 * <p>CaptureRequests can be created by using a {@link Builder} instance,
 * obtained by calling {@link CameraDevice#createCaptureRequest}</p>
 *
 * <p>CaptureRequests are given to {@link CameraDevice#capture} or
 * {@link CameraDevice#setRepeatingRequest} to capture images from a camera.</p>
 *
 * <p>Each request can specify a different subset of target Surfaces for the
 * camera to send the captured data to. All the surfaces used in a request must
 * be part of the surface list given to the last call to
 * {@link CameraDevice#configureOutputs}, when the request is submitted to the
 * camera device.</p>
 *
 * <p>For example, a request meant for repeating preview might only include the
 * Surface for the preview SurfaceView or SurfaceTexture, while a
 * high-resolution still capture would also include a Surface from a ImageReader
 * configured for high-resolution JPEG images.</p>
 *
 * @see CameraDevice#capture
 * @see CameraDevice#setRepeatingRequest
 * @see CameraDevice#createCaptureRequest
 */
public final class CaptureRequest extends CameraMetadata implements Parcelable {

    private final HashSet<Surface> mSurfaceSet;
    private final CameraMetadataNative mSettings;

    private Object mUserTag;

    /**
     * Construct empty request.
     *
     * Used by Binder to unparcel this object only.
     */
    private CaptureRequest() {
        mSettings = new CameraMetadataNative();
        mSurfaceSet = new HashSet<Surface>();
    }

    /**
     * Clone from source capture request.
     *
     * Used by the Builder to create an immutable copy.
     */
    @SuppressWarnings("unchecked")
    private CaptureRequest(CaptureRequest source) {
        mSettings = new CameraMetadataNative(source.mSettings);
        mSurfaceSet = (HashSet<Surface>) source.mSurfaceSet.clone();
        mUserTag = source.mUserTag;
    }

    /**
     * Take ownership of passed-in settings.
     *
     * Used by the Builder to create a mutable CaptureRequest.
     */
    private CaptureRequest(CameraMetadataNative settings) {
        mSettings = settings;
        mSurfaceSet = new HashSet<Surface>();
    }

    @SuppressWarnings("unchecked")
    @Override
    public <T> T get(Key<T> key) {
        return mSettings.get(key);
    }

    /**
     * Retrieve the tag for this request, if any.
     *
     * <p>This tag is not used for anything by the camera device, but can be
     * used by an application to easily identify a CaptureRequest when it is
     * returned by
     * {@link CameraDevice.CaptureListener#onCaptureCompleted CaptureListener.onCaptureCompleted}
     * </p>
     *
     * @return the last tag Object set on this request, or {@code null} if
     *     no tag has been set.
     * @see Builder#setTag
     */
    public Object getTag() {
        return mUserTag;
    }

    /**
     * Determine whether this CaptureRequest is equal to another CaptureRequest.
     *
     * <p>A request is considered equal to another is if it's set of key/values is equal, it's
     * list of output surfaces is equal, and the user tag is equal.</p>
     *
     * @param other Another instance of CaptureRequest.
     *
     * @return True if the requests are the same, false otherwise.
     */
    @Override
    public boolean equals(Object other) {
        return other instanceof CaptureRequest
                && equals((CaptureRequest)other);
    }

    private boolean equals(CaptureRequest other) {
        return other != null
                && Objects.equals(mUserTag, other.mUserTag)
                && mSurfaceSet.equals(other.mSurfaceSet)
                && mSettings.equals(other.mSettings);
    }

    @Override
    public int hashCode() {
        return mSettings.hashCode();
    }

    public static final Parcelable.Creator<CaptureRequest> CREATOR =
            new Parcelable.Creator<CaptureRequest>() {
        @Override
        public CaptureRequest createFromParcel(Parcel in) {
            CaptureRequest request = new CaptureRequest();
            request.readFromParcel(in);

            return request;
        }

        @Override
        public CaptureRequest[] newArray(int size) {
            return new CaptureRequest[size];
        }
    };

    /**
     * Expand this object from a Parcel.
     * Hidden since this breaks the immutability of CaptureRequest, but is
     * needed to receive CaptureRequests with aidl.
     *
     * @param in The parcel from which the object should be read
     * @hide
     */
    public void readFromParcel(Parcel in) {
        mSettings.readFromParcel(in);

        mSurfaceSet.clear();

        Parcelable[] parcelableArray = in.readParcelableArray(Surface.class.getClassLoader());

        if (parcelableArray == null) {
            return;
        }

        for (Parcelable p : parcelableArray) {
            Surface s = (Surface) p;
            mSurfaceSet.add(s);
        }
    }

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

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        mSettings.writeToParcel(dest, flags);
        dest.writeParcelableArray(mSurfaceSet.toArray(new Surface[mSurfaceSet.size()]), flags);
    }

    /**
     * A builder for capture requests.
     *
     * <p>To obtain a builder instance, use the
     * {@link CameraDevice#createCaptureRequest} method, which initializes the
     * request fields to one of the templates defined in {@link CameraDevice}.
     *
     * @see CameraDevice#createCaptureRequest
     * @see #TEMPLATE_PREVIEW
     * @see #TEMPLATE_RECORD
     * @see #TEMPLATE_STILL_CAPTURE
     * @see #TEMPLATE_VIDEO_SNAPSHOT
     * @see #TEMPLATE_MANUAL
     */
    public final static class Builder {

        private final CaptureRequest mRequest;

        /**
         * Initialize the builder using the template; the request takes
         * ownership of the template.
         *
         * @hide
         */
        public Builder(CameraMetadataNative template) {
            mRequest = new CaptureRequest(template);
        }

        /**
         * <p>Add a surface to the list of targets for this request</p>
         *
         * <p>The Surface added must be one of the surfaces included in the most
         * recent call to {@link CameraDevice#configureOutputs}, when the
         * request is given to the camera device.</p>
         *
         * <p>Adding a target more than once has no effect.</p>
         *
         * @param outputTarget Surface to use as an output target for this request
         */
        public void addTarget(Surface outputTarget) {
            mRequest.mSurfaceSet.add(outputTarget);
        }

        /**
         * <p>Remove a surface from the list of targets for this request.</p>
         *
         * <p>Removing a target that is not currently added has no effect.</p>
         *
         * @param outputTarget Surface to use as an output target for this request
         */
        public void removeTarget(Surface outputTarget) {
            mRequest.mSurfaceSet.remove(outputTarget);
        }

        /**
         * Set a capture request field to a value. The field definitions can be
         * found in {@link CaptureRequest}.
         *
         * @param key The metadata field to write.
         * @param value The value to set the field to, which must be of a matching
         * type to the key.
         */
        public <T> void set(Key<T> key, T value) {
            mRequest.mSettings.set(key, value);
        }

        /**
         * Get a capture request field value. The field definitions can be
         * found in {@link CaptureRequest}.
         *
         * @throws IllegalArgumentException if the key was not valid
         *
         * @param key The metadata field to read.
         * @return The value of that key, or {@code null} if the field is not set.
         */
        public <T> T get(Key<T> key) {
            return mRequest.mSettings.get(key);
        }

        /**
         * Set a tag for this request.
         *
         * <p>This tag is not used for anything by the camera device, but can be
         * used by an application to easily identify a CaptureRequest when it is
         * returned by
         * {@link CameraDevice.CaptureListener#onCaptureCompleted CaptureListener.onCaptureCompleted}
         *
         * @param tag an arbitrary Object to store with this request
         * @see CaptureRequest#getTag
         */
        public void setTag(Object tag) {
            mRequest.mUserTag = tag;
        }

        /**
         * Build a request using the current target Surfaces and settings.
         *
         * @return A new capture request instance, ready for submission to the
         * camera device.
         */
        public CaptureRequest build() {
            return new CaptureRequest(mRequest);
        }


        /**
         * @hide
         */
        public boolean isEmpty() {
            return mRequest.mSettings.isEmpty();
        }

    }

    /*@O~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~
     * The key entries below this point are generated from metadata
     * definitions in /system/media/camera/docs. Do not modify by hand or
     * modify the comment blocks at the start or end.
     *~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~*/


    /**
     * <p>The mode control selects how the image data is converted from the
     * sensor's native color into linear sRGB color.</p>
     * <p>When auto-white balance is enabled with {@link CaptureRequest#CONTROL_AWB_MODE android.control.awbMode}, this
     * control is overridden by the AWB routine. When AWB is disabled, the
     * application controls how the color mapping is performed.</p>
     * <p>We define the expected processing pipeline below. For consistency
     * across devices, this is always the case with TRANSFORM_MATRIX.</p>
     * <p>When either FULL or HIGH_QUALITY is used, the camera device may
     * do additional processing but {@link CaptureRequest#COLOR_CORRECTION_GAINS android.colorCorrection.gains} and
     * {@link CaptureRequest#COLOR_CORRECTION_TRANSFORM android.colorCorrection.transform} will still be provided by the
     * camera device (in the results) and be roughly correct.</p>
     * <p>Switching to TRANSFORM_MATRIX and using the data provided from
     * FAST or HIGH_QUALITY will yield a picture with the same white point
     * as what was produced by the camera device in the earlier frame.</p>
     * <p>The expected processing pipeline is as follows:</p>
     * <p><img alt="White balance processing pipeline" src="../../../../images/camera2/metadata/android.colorCorrection.mode/processing_pipeline.png" /></p>
     * <p>The white balance is encoded by two values, a 4-channel white-balance
     * gain vector (applied in the Bayer domain), and a 3x3 color transform
     * matrix (applied after demosaic).</p>
     * <p>The 4-channel white-balance gains are defined as:</p>
     * <pre><code>{@link CaptureRequest#COLOR_CORRECTION_GAINS android.colorCorrection.gains} = [ R G_even G_odd B ]
     * </code></pre>
     * <p>where <code>G_even</code> is the gain for green pixels on even rows of the
     * output, and <code>G_odd</code> is the gain for green pixels on the odd rows.
     * These may be identical for a given camera device implementation; if
     * the camera device does not support a separate gain for even/odd green
     * channels, it will use the <code>G_even</code> value, and write <code>G_odd</code> equal to
     * <code>G_even</code> in the output result metadata.</p>
     * <p>The matrices for color transforms are defined as a 9-entry vector:</p>
     * <pre><code>{@link CaptureRequest#COLOR_CORRECTION_TRANSFORM android.colorCorrection.transform} = [ I0 I1 I2 I3 I4 I5 I6 I7 I8 ]
     * </code></pre>
     * <p>which define a transform from input sensor colors, <code>P_in = [ r g b ]</code>,
     * to output linear sRGB, <code>P_out = [ r' g' b' ]</code>,</p>
     * <p>with colors as follows:</p>
     * <pre><code>r' = I0r + I1g + I2b
     * g' = I3r + I4g + I5b
     * b' = I6r + I7g + I8b
     * </code></pre>
     * <p>Both the input and output value ranges must match. Overflow/underflow
     * values are clipped to fit within the range.</p>
     *
     * @see CaptureRequest#COLOR_CORRECTION_GAINS
     * @see CaptureRequest#COLOR_CORRECTION_TRANSFORM
     * @see CaptureRequest#CONTROL_AWB_MODE
     * @see #COLOR_CORRECTION_MODE_TRANSFORM_MATRIX
     * @see #COLOR_CORRECTION_MODE_FAST
     * @see #COLOR_CORRECTION_MODE_HIGH_QUALITY
     */
    public static final Key<Integer> COLOR_CORRECTION_MODE =
            new Key<Integer>("android.colorCorrection.mode", int.class);

    /**
     * <p>A color transform matrix to use to transform
     * from sensor RGB color space to output linear sRGB color space</p>
     * <p>This matrix is either set by the camera device when the request
     * {@link CaptureRequest#COLOR_CORRECTION_MODE android.colorCorrection.mode} is not TRANSFORM_MATRIX, or
     * directly by the application in the request when the
     * {@link CaptureRequest#COLOR_CORRECTION_MODE android.colorCorrection.mode} is TRANSFORM_MATRIX.</p>
     * <p>In the latter case, the camera device may round the matrix to account
     * for precision issues; the final rounded matrix should be reported back
     * in this matrix result metadata. The transform should keep the magnitude
     * of the output color values within <code>[0, 1.0]</code> (assuming input color
     * values is within the normalized range <code>[0, 1.0]</code>), or clipping may occur.</p>
     *
     * @see CaptureRequest#COLOR_CORRECTION_MODE
     */
    public static final Key<Rational[]> COLOR_CORRECTION_TRANSFORM =
            new Key<Rational[]>("android.colorCorrection.transform", Rational[].class);

    /**
     * <p>Gains applying to Bayer raw color channels for
     * white-balance.</p>
     * <p>The 4-channel white-balance gains are defined in
     * the order of <code>[R G_even G_odd B]</code>, where <code>G_even</code> is the gain
     * for green pixels on even rows of the output, and <code>G_odd</code>
     * is the gain for green pixels on the odd rows. if a HAL
     * does not support a separate gain for even/odd green channels,
     * it should use the <code>G_even</code> value, and write <code>G_odd</code> equal to
     * <code>G_even</code> in the output result metadata.</p>
     * <p>This array is either set by the camera device when the request
     * {@link CaptureRequest#COLOR_CORRECTION_MODE android.colorCorrection.mode} is not TRANSFORM_MATRIX, or
     * directly by the application in the request when the
     * {@link CaptureRequest#COLOR_CORRECTION_MODE android.colorCorrection.mode} is TRANSFORM_MATRIX.</p>
     * <p>The output should be the gains actually applied by the camera device to
     * the current frame.</p>
     *
     * @see CaptureRequest#COLOR_CORRECTION_MODE
     */
    public static final Key<float[]> COLOR_CORRECTION_GAINS =
            new Key<float[]>("android.colorCorrection.gains", float[].class);

    /**
     * <p>The desired setting for the camera device's auto-exposure
     * algorithm's antibanding compensation.</p>
     * <p>Some kinds of lighting fixtures, such as some fluorescent
     * lights, flicker at the rate of the power supply frequency
     * (60Hz or 50Hz, depending on country). While this is
     * typically not noticeable to a person, it can be visible to
     * a camera device. If a camera sets its exposure time to the
     * wrong value, the flicker may become visible in the
     * viewfinder as flicker or in a final captured image, as a
     * set of variable-brightness bands across the image.</p>
     * <p>Therefore, the auto-exposure routines of camera devices
     * include antibanding routines that ensure that the chosen
     * exposure value will not cause such banding. The choice of
     * exposure time depends on the rate of flicker, which the
     * camera device can detect automatically, or the expected
     * rate can be selected by the application using this
     * control.</p>
     * <p>A given camera device may not support all of the possible
     * options for the antibanding mode. The
     * {@link CameraCharacteristics#CONTROL_AE_AVAILABLE_ANTIBANDING_MODES android.control.aeAvailableAntibandingModes} key contains
     * the available modes for a given camera device.</p>
     * <p>The default mode is AUTO, which must be supported by all
     * camera devices.</p>
     * <p>If manual exposure control is enabled (by setting
     * {@link CaptureRequest#CONTROL_AE_MODE android.control.aeMode} or {@link CaptureRequest#CONTROL_MODE android.control.mode} to OFF),
     * then this setting has no effect, and the application must
     * ensure it selects exposure times that do not cause banding
     * issues. The {@link CaptureResult#STATISTICS_SCENE_FLICKER android.statistics.sceneFlicker} key can assist
     * the application in this.</p>
     *
     * @see CameraCharacteristics#CONTROL_AE_AVAILABLE_ANTIBANDING_MODES
     * @see CaptureRequest#CONTROL_AE_MODE
     * @see CaptureRequest#CONTROL_MODE
     * @see CaptureResult#STATISTICS_SCENE_FLICKER
     * @see #CONTROL_AE_ANTIBANDING_MODE_OFF
     * @see #CONTROL_AE_ANTIBANDING_MODE_50HZ
     * @see #CONTROL_AE_ANTIBANDING_MODE_60HZ
     * @see #CONTROL_AE_ANTIBANDING_MODE_AUTO
     */
    public static final Key<Integer> CONTROL_AE_ANTIBANDING_MODE =
            new Key<Integer>("android.control.aeAntibandingMode", int.class);

    /**
     * <p>Adjustment to AE target image
     * brightness</p>
     * <p>For example, if EV step is 0.333, '6' will mean an
     * exposure compensation of +2 EV; -3 will mean an exposure
     * compensation of -1</p>
     */
    public static final Key<Integer> CONTROL_AE_EXPOSURE_COMPENSATION =
            new Key<Integer>("android.control.aeExposureCompensation", int.class);

    /**
     * <p>Whether AE is currently locked to its latest
     * calculated values.</p>
     * <p>Note that even when AE is locked, the flash may be
     * fired if the {@link CaptureRequest#CONTROL_AE_MODE android.control.aeMode} is ON_AUTO_FLASH / ON_ALWAYS_FLASH /
     * ON_AUTO_FLASH_REDEYE.</p>
     * <p>If AE precapture is triggered (see {@link CaptureRequest#CONTROL_AE_PRECAPTURE_TRIGGER android.control.aePrecaptureTrigger})
     * when AE is already locked, the camera device will not change the exposure time
     * ({@link CaptureRequest#SENSOR_EXPOSURE_TIME android.sensor.exposureTime}) and sensitivity ({@link CaptureRequest#SENSOR_SENSITIVITY android.sensor.sensitivity})
     * parameters. The flash may be fired if the {@link CaptureRequest#CONTROL_AE_MODE android.control.aeMode}
     * is ON_AUTO_FLASH/ON_AUTO_FLASH_REDEYE and the scene is too dark. If the
     * {@link CaptureRequest#CONTROL_AE_MODE android.control.aeMode} is ON_ALWAYS_FLASH, the scene may become overexposed.</p>
     * <p>See {@link CaptureResult#CONTROL_AE_STATE android.control.aeState} for AE lock related state transition details.</p>
     *
     * @see CaptureRequest#CONTROL_AE_MODE
     * @see CaptureRequest#CONTROL_AE_PRECAPTURE_TRIGGER
     * @see CaptureResult#CONTROL_AE_STATE
     * @see CaptureRequest#SENSOR_EXPOSURE_TIME
     * @see CaptureRequest#SENSOR_SENSITIVITY
     */
    public static final Key<Boolean> CONTROL_AE_LOCK =
            new Key<Boolean>("android.control.aeLock", boolean.class);

    /**
     * <p>The desired mode for the camera device's
     * auto-exposure routine.</p>
     * <p>This control is only effective if {@link CaptureRequest#CONTROL_MODE android.control.mode} is
     * AUTO.</p>
     * <p>When set to any of the ON modes, the camera device's
     * auto-exposure routine is enabled, overriding the
     * application's selected exposure time, sensor sensitivity,
     * and frame duration ({@link CaptureRequest#SENSOR_EXPOSURE_TIME android.sensor.exposureTime},
     * {@link CaptureRequest#SENSOR_SENSITIVITY android.sensor.sensitivity}, and
     * {@link CaptureRequest#SENSOR_FRAME_DURATION android.sensor.frameDuration}). If one of the FLASH modes
     * is selected, the camera device's flash unit controls are
     * also overridden.</p>
     * <p>The FLASH modes are only available if the camera device
     * has a flash unit ({@link CameraCharacteristics#FLASH_INFO_AVAILABLE android.flash.info.available} is <code>true</code>).</p>
     * <p>If flash TORCH mode is desired, this field must be set to
     * ON or OFF, and {@link CaptureRequest#FLASH_MODE android.flash.mode} set to TORCH.</p>
     * <p>When set to any of the ON modes, the values chosen by the
     * camera device auto-exposure routine for the overridden
     * fields for a given capture will be available in its
     * CaptureResult.</p>
     *
     * @see CaptureRequest#CONTROL_MODE
     * @see CameraCharacteristics#FLASH_INFO_AVAILABLE
     * @see CaptureRequest#FLASH_MODE
     * @see CaptureRequest#SENSOR_EXPOSURE_TIME
     * @see CaptureRequest#SENSOR_FRAME_DURATION
     * @see CaptureRequest#SENSOR_SENSITIVITY
     * @see #CONTROL_AE_MODE_OFF
     * @see #CONTROL_AE_MODE_ON
     * @see #CONTROL_AE_MODE_ON_AUTO_FLASH
     * @see #CONTROL_AE_MODE_ON_ALWAYS_FLASH
     * @see #CONTROL_AE_MODE_ON_AUTO_FLASH_REDEYE
     */
    public static final Key<Integer> CONTROL_AE_MODE =
            new Key<Integer>("android.control.aeMode", int.class);

    /**
     * <p>List of areas to use for
     * metering.</p>
     * <p>Each area is a rectangle plus weight: xmin, ymin,
     * xmax, ymax, weight. The rectangle is defined to be inclusive of the
     * specified coordinates.</p>
     * <p>The coordinate system is based on the active pixel array,
     * with (0,0) being the top-left pixel in the active pixel array, and
     * ({@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.width - 1,
     * {@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.height - 1) being the
     * bottom-right pixel in the active pixel array. The weight
     * should be nonnegative.</p>
     * <p>If all regions have 0 weight, then no specific metering area
     * needs to be used by the camera device. If the metering region is
     * outside the current {@link CaptureRequest#SCALER_CROP_REGION android.scaler.cropRegion}, the camera device
     * will ignore the sections outside the region and output the
     * used sections in the frame metadata.</p>
     *
     * @see CaptureRequest#SCALER_CROP_REGION
     * @see CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE
     */
    public static final Key<int[]> CONTROL_AE_REGIONS =
            new Key<int[]>("android.control.aeRegions", int[].class);

    /**
     * <p>Range over which fps can be adjusted to
     * maintain exposure</p>
     * <p>Only constrains AE algorithm, not manual control
     * of {@link CaptureRequest#SENSOR_EXPOSURE_TIME android.sensor.exposureTime}</p>
     *
     * @see CaptureRequest#SENSOR_EXPOSURE_TIME
     */
    public static final Key<int[]> CONTROL_AE_TARGET_FPS_RANGE =
            new Key<int[]>("android.control.aeTargetFpsRange", int[].class);

    /**
     * <p>Whether the camera device will trigger a precapture
     * metering sequence when it processes this request.</p>
     * <p>This entry is normally set to IDLE, or is not
     * included at all in the request settings. When included and
     * set to START, the camera device will trigger the autoexposure
     * precapture metering sequence.</p>
     * <p>The effect of AE precapture trigger depends on the current
     * AE mode and state; see {@link CaptureResult#CONTROL_AE_STATE android.control.aeState} for AE precapture
     * state transition details.</p>
     *
     * @see CaptureResult#CONTROL_AE_STATE
     * @see #CONTROL_AE_PRECAPTURE_TRIGGER_IDLE
     * @see #CONTROL_AE_PRECAPTURE_TRIGGER_START
     */
    public static final Key<Integer> CONTROL_AE_PRECAPTURE_TRIGGER =
            new Key<Integer>("android.control.aePrecaptureTrigger", int.class);

    /**
     * <p>Whether AF is currently enabled, and what
     * mode it is set to</p>
     * <p>Only effective if {@link CaptureRequest#CONTROL_MODE android.control.mode} = AUTO and the lens is not fixed focus
     * (i.e. <code>{@link CameraCharacteristics#LENS_INFO_MINIMUM_FOCUS_DISTANCE android.lens.info.minimumFocusDistance} &gt; 0</code>).</p>
     * <p>If the lens is controlled by the camera device auto-focus algorithm,
     * the camera device will report the current AF status in {@link CaptureResult#CONTROL_AF_STATE android.control.afState}
     * in result metadata.</p>
     *
     * @see CaptureResult#CONTROL_AF_STATE
     * @see CaptureRequest#CONTROL_MODE
     * @see CameraCharacteristics#LENS_INFO_MINIMUM_FOCUS_DISTANCE
     * @see #CONTROL_AF_MODE_OFF
     * @see #CONTROL_AF_MODE_AUTO
     * @see #CONTROL_AF_MODE_MACRO
     * @see #CONTROL_AF_MODE_CONTINUOUS_VIDEO
     * @see #CONTROL_AF_MODE_CONTINUOUS_PICTURE
     * @see #CONTROL_AF_MODE_EDOF
     */
    public static final Key<Integer> CONTROL_AF_MODE =
            new Key<Integer>("android.control.afMode", int.class);

    /**
     * <p>List of areas to use for focus
     * estimation.</p>
     * <p>Each area is a rectangle plus weight: xmin, ymin,
     * xmax, ymax, weight. The rectangle is defined to be inclusive of the
     * specified coordinates.</p>
     * <p>The coordinate system is based on the active pixel array,
     * with (0,0) being the top-left pixel in the active pixel array, and
     * ({@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.width - 1,
     * {@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.height - 1) being the
     * bottom-right pixel in the active pixel array. The weight
     * should be nonnegative.</p>
     * <p>If all regions have 0 weight, then no specific focus area
     * needs to be used by the camera device. If the focusing region is
     * outside the current {@link CaptureRequest#SCALER_CROP_REGION android.scaler.cropRegion}, the camera device
     * will ignore the sections outside the region and output the
     * used sections in the frame metadata.</p>
     *
     * @see CaptureRequest#SCALER_CROP_REGION
     * @see CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE
     */
    public static final Key<int[]> CONTROL_AF_REGIONS =
            new Key<int[]>("android.control.afRegions", int[].class);

    /**
     * <p>Whether the camera device will trigger autofocus for this request.</p>
     * <p>This entry is normally set to IDLE, or is not
     * included at all in the request settings.</p>
     * <p>When included and set to START, the camera device will trigger the
     * autofocus algorithm. If autofocus is disabled, this trigger has no effect.</p>
     * <p>When set to CANCEL, the camera device will cancel any active trigger,
     * and return to its initial AF state.</p>
     * <p>See {@link CaptureResult#CONTROL_AF_STATE android.control.afState} for what that means for each AF mode.</p>
     *
     * @see CaptureResult#CONTROL_AF_STATE
     * @see #CONTROL_AF_TRIGGER_IDLE
     * @see #CONTROL_AF_TRIGGER_START
     * @see #CONTROL_AF_TRIGGER_CANCEL
     */
    public static final Key<Integer> CONTROL_AF_TRIGGER =
            new Key<Integer>("android.control.afTrigger", int.class);

    /**
     * <p>Whether AWB is currently locked to its
     * latest calculated values.</p>
     * <p>Note that AWB lock is only meaningful for AUTO
     * mode; in other modes, AWB is already fixed to a specific
     * setting.</p>
     */
    public static final Key<Boolean> CONTROL_AWB_LOCK =
            new Key<Boolean>("android.control.awbLock", boolean.class);

    /**
     * <p>Whether AWB is currently setting the color
     * transform fields, and what its illumination target
     * is.</p>
     * <p>This control is only effective if {@link CaptureRequest#CONTROL_MODE android.control.mode} is AUTO.</p>
     * <p>When set to the ON mode, the camera device's auto white balance
     * routine is enabled, overriding the application's selected
     * {@link CaptureRequest#COLOR_CORRECTION_TRANSFORM android.colorCorrection.transform}, {@link CaptureRequest#COLOR_CORRECTION_GAINS android.colorCorrection.gains} and
     * {@link CaptureRequest#COLOR_CORRECTION_MODE android.colorCorrection.mode}.</p>
     * <p>When set to the OFF mode, the camera device's auto white balance
     * routine is disabled. The application manually controls the white
     * balance by {@link CaptureRequest#COLOR_CORRECTION_TRANSFORM android.colorCorrection.transform}, {@link CaptureRequest#COLOR_CORRECTION_GAINS android.colorCorrection.gains}
     * and {@link CaptureRequest#COLOR_CORRECTION_MODE android.colorCorrection.mode}.</p>
     * <p>When set to any other modes, the camera device's auto white balance
     * routine is disabled. The camera device uses each particular illumination
     * target for white balance adjustment.</p>
     *
     * @see CaptureRequest#COLOR_CORRECTION_GAINS
     * @see CaptureRequest#COLOR_CORRECTION_MODE
     * @see CaptureRequest#COLOR_CORRECTION_TRANSFORM
     * @see CaptureRequest#CONTROL_MODE
     * @see #CONTROL_AWB_MODE_OFF
     * @see #CONTROL_AWB_MODE_AUTO
     * @see #CONTROL_AWB_MODE_INCANDESCENT
     * @see #CONTROL_AWB_MODE_FLUORESCENT
     * @see #CONTROL_AWB_MODE_WARM_FLUORESCENT
     * @see #CONTROL_AWB_MODE_DAYLIGHT
     * @see #CONTROL_AWB_MODE_CLOUDY_DAYLIGHT
     * @see #CONTROL_AWB_MODE_TWILIGHT
     * @see #CONTROL_AWB_MODE_SHADE
     */
    public static final Key<Integer> CONTROL_AWB_MODE =
            new Key<Integer>("android.control.awbMode", int.class);

    /**
     * <p>List of areas to use for illuminant
     * estimation.</p>
     * <p>Only used in AUTO mode.</p>
     * <p>Each area is a rectangle plus weight: xmin, ymin,
     * xmax, ymax, weight. The rectangle is defined to be inclusive of the
     * specified coordinates.</p>
     * <p>The coordinate system is based on the active pixel array,
     * with (0,0) being the top-left pixel in the active pixel array, and
     * ({@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.width - 1,
     * {@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.height - 1) being the
     * bottom-right pixel in the active pixel array. The weight
     * should be nonnegative.</p>
     * <p>If all regions have 0 weight, then no specific auto-white balance (AWB) area
     * needs to be used by the camera device. If the AWB region is
     * outside the current {@link CaptureRequest#SCALER_CROP_REGION android.scaler.cropRegion}, the camera device
     * will ignore the sections outside the region and output the
     * used sections in the frame metadata.</p>
     *
     * @see CaptureRequest#SCALER_CROP_REGION
     * @see CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE
     */
    public static final Key<int[]> CONTROL_AWB_REGIONS =
            new Key<int[]>("android.control.awbRegions", int[].class);

    /**
     * <p>Information to the camera device 3A (auto-exposure,
     * auto-focus, auto-white balance) routines about the purpose
     * of this capture, to help the camera device to decide optimal 3A
     * strategy.</p>
     * <p>This control (except for MANUAL) is only effective if
     * <code>{@link CaptureRequest#CONTROL_MODE android.control.mode} != OFF</code> and any 3A routine is active.</p>
     * <p>ZERO_SHUTTER_LAG must be supported if {@link CameraCharacteristics#REQUEST_AVAILABLE_CAPABILITIES android.request.availableCapabilities}
     * contains ZSL. MANUAL must be supported if {@link CameraCharacteristics#REQUEST_AVAILABLE_CAPABILITIES android.request.availableCapabilities}
     * contains MANUAL_SENSOR.</p>
     *
     * @see CaptureRequest#CONTROL_MODE
     * @see CameraCharacteristics#REQUEST_AVAILABLE_CAPABILITIES
     * @see #CONTROL_CAPTURE_INTENT_CUSTOM
     * @see #CONTROL_CAPTURE_INTENT_PREVIEW
     * @see #CONTROL_CAPTURE_INTENT_STILL_CAPTURE
     * @see #CONTROL_CAPTURE_INTENT_VIDEO_RECORD
     * @see #CONTROL_CAPTURE_INTENT_VIDEO_SNAPSHOT
     * @see #CONTROL_CAPTURE_INTENT_ZERO_SHUTTER_LAG
     * @see #CONTROL_CAPTURE_INTENT_MANUAL
     */
    public static final Key<Integer> CONTROL_CAPTURE_INTENT =
            new Key<Integer>("android.control.captureIntent", int.class);

    /**
     * <p>A special color effect to apply.</p>
     * <p>When this mode is set, a color effect will be applied
     * to images produced by the camera device. The interpretation
     * and implementation of these color effects is left to the
     * implementor of the camera device, and should not be
     * depended on to be consistent (or present) across all
     * devices.</p>
     * <p>A color effect will only be applied if
     * {@link CaptureRequest#CONTROL_MODE android.control.mode} != OFF.</p>
     *
     * @see CaptureRequest#CONTROL_MODE
     * @see #CONTROL_EFFECT_MODE_OFF
     * @see #CONTROL_EFFECT_MODE_MONO
     * @see #CONTROL_EFFECT_MODE_NEGATIVE
     * @see #CONTROL_EFFECT_MODE_SOLARIZE
     * @see #CONTROL_EFFECT_MODE_SEPIA
     * @see #CONTROL_EFFECT_MODE_POSTERIZE
     * @see #CONTROL_EFFECT_MODE_WHITEBOARD
     * @see #CONTROL_EFFECT_MODE_BLACKBOARD
     * @see #CONTROL_EFFECT_MODE_AQUA
     */
    public static final Key<Integer> CONTROL_EFFECT_MODE =
            new Key<Integer>("android.control.effectMode", int.class);

    /**
     * <p>Overall mode of 3A control
     * routines.</p>
     * <p>High-level 3A control. When set to OFF, all 3A control
     * by the camera device is disabled. The application must set the fields for
     * capture parameters itself.</p>
     * <p>When set to AUTO, the individual algorithm controls in
     * android.control.* are in effect, such as {@link CaptureRequest#CONTROL_AF_MODE android.control.afMode}.</p>
     * <p>When set to USE_SCENE_MODE, the individual controls in
     * android.control.* are mostly disabled, and the camera device implements
     * one of the scene mode settings (such as ACTION, SUNSET, or PARTY)
     * as it wishes. The camera device scene mode 3A settings are provided by
     * android.control.sceneModeOverrides.</p>
     * <p>When set to OFF_KEEP_STATE, it is similar to OFF mode, the only difference
     * is that this frame will not be used by camera device background 3A statistics
     * update, as if this frame is never captured. This mode can be used in the scenario
     * where the application doesn't want a 3A manual control capture to affect
     * the subsequent auto 3A capture results.</p>
     *
     * @see CaptureRequest#CONTROL_AF_MODE
     * @see #CONTROL_MODE_OFF
     * @see #CONTROL_MODE_AUTO
     * @see #CONTROL_MODE_USE_SCENE_MODE
     * @see #CONTROL_MODE_OFF_KEEP_STATE
     */
    public static final Key<Integer> CONTROL_MODE =
            new Key<Integer>("android.control.mode", int.class);

    /**
     * <p>A camera mode optimized for conditions typical in a particular
     * capture setting.</p>
     * <p>This is the mode that that is active when
     * <code>{@link CaptureRequest#CONTROL_MODE android.control.mode} == USE_SCENE_MODE</code>. Aside from FACE_PRIORITY,
     * these modes will disable {@link CaptureRequest#CONTROL_AE_MODE android.control.aeMode},
     * {@link CaptureRequest#CONTROL_AWB_MODE android.control.awbMode}, and {@link CaptureRequest#CONTROL_AF_MODE android.control.afMode} while in use.</p>
     * <p>The interpretation and implementation of these scene modes is left
     * to the implementor of the camera device. Their behavior will not be
     * consistent across all devices, and any given device may only implement
     * a subset of these modes.</p>
     *
     * @see CaptureRequest#CONTROL_AE_MODE
     * @see CaptureRequest#CONTROL_AF_MODE
     * @see CaptureRequest#CONTROL_AWB_MODE
     * @see CaptureRequest#CONTROL_MODE
     * @see #CONTROL_SCENE_MODE_DISABLED
     * @see #CONTROL_SCENE_MODE_FACE_PRIORITY
     * @see #CONTROL_SCENE_MODE_ACTION
     * @see #CONTROL_SCENE_MODE_PORTRAIT
     * @see #CONTROL_SCENE_MODE_LANDSCAPE
     * @see #CONTROL_SCENE_MODE_NIGHT
     * @see #CONTROL_SCENE_MODE_NIGHT_PORTRAIT
     * @see #CONTROL_SCENE_MODE_THEATRE
     * @see #CONTROL_SCENE_MODE_BEACH
     * @see #CONTROL_SCENE_MODE_SNOW
     * @see #CONTROL_SCENE_MODE_SUNSET
     * @see #CONTROL_SCENE_MODE_STEADYPHOTO
     * @see #CONTROL_SCENE_MODE_FIREWORKS
     * @see #CONTROL_SCENE_MODE_SPORTS
     * @see #CONTROL_SCENE_MODE_PARTY
     * @see #CONTROL_SCENE_MODE_CANDLELIGHT
     * @see #CONTROL_SCENE_MODE_BARCODE
     */
    public static final Key<Integer> CONTROL_SCENE_MODE =
            new Key<Integer>("android.control.sceneMode", int.class);

    /**
     * <p>Whether video stabilization is
     * active</p>
     * <p>If enabled, video stabilization can modify the
     * {@link CaptureRequest#SCALER_CROP_REGION android.scaler.cropRegion} to keep the video stream
     * stabilized</p>
     *
     * @see CaptureRequest#SCALER_CROP_REGION
     */
    public static final Key<Boolean> CONTROL_VIDEO_STABILIZATION_MODE =
            new Key<Boolean>("android.control.videoStabilizationMode", boolean.class);

    /**
     * <p>Operation mode for edge
     * enhancement.</p>
     * <p>Edge/sharpness/detail enhancement. OFF means no
     * enhancement will be applied by the camera device.</p>
     * <p>This must be set to one of the modes listed in {@link CameraCharacteristics#EDGE_AVAILABLE_EDGE_MODES android.edge.availableEdgeModes}.</p>
     * <p>FAST/HIGH_QUALITY both mean camera device determined enhancement
     * will be applied. HIGH_QUALITY mode indicates that the
     * camera device will use the highest-quality enhancement algorithms,
     * even if it slows down capture rate. FAST means the camera device will
     * not slow down capture rate when applying edge enhancement.</p>
     *
     * @see CameraCharacteristics#EDGE_AVAILABLE_EDGE_MODES
     * @see #EDGE_MODE_OFF
     * @see #EDGE_MODE_FAST
     * @see #EDGE_MODE_HIGH_QUALITY
     */
    public static final Key<Integer> EDGE_MODE =
            new Key<Integer>("android.edge.mode", int.class);

    /**
     * <p>The desired mode for for the camera device's flash control.</p>
     * <p>This control is only effective when flash unit is available
     * (<code>{@link CameraCharacteristics#FLASH_INFO_AVAILABLE android.flash.info.available} == true</code>).</p>
     * <p>When this control is used, the {@link CaptureRequest#CONTROL_AE_MODE android.control.aeMode} must be set to ON or OFF.
     * Otherwise, the camera device auto-exposure related flash control (ON_AUTO_FLASH,
     * ON_ALWAYS_FLASH, or ON_AUTO_FLASH_REDEYE) will override this control.</p>
     * <p>When set to OFF, the camera device will not fire flash for this capture.</p>
     * <p>When set to SINGLE, the camera device will fire flash regardless of the camera
     * device's auto-exposure routine's result. When used in still capture case, this
     * control should be used along with AE precapture metering sequence
     * ({@link CaptureRequest#CONTROL_AE_PRECAPTURE_TRIGGER android.control.aePrecaptureTrigger}), otherwise, the image may be incorrectly exposed.</p>
     * <p>When set to TORCH, the flash will be on continuously. This mode can be used
     * for use cases such as preview, auto-focus assist, still capture, or video recording.</p>
     * <p>The flash status will be reported by {@link CaptureResult#FLASH_STATE android.flash.state} in the capture result metadata.</p>
     *
     * @see CaptureRequest#CONTROL_AE_MODE
     * @see CaptureRequest#CONTROL_AE_PRECAPTURE_TRIGGER
     * @see CameraCharacteristics#FLASH_INFO_AVAILABLE
     * @see CaptureResult#FLASH_STATE
     * @see #FLASH_MODE_OFF
     * @see #FLASH_MODE_SINGLE
     * @see #FLASH_MODE_TORCH
     */
    public static final Key<Integer> FLASH_MODE =
            new Key<Integer>("android.flash.mode", int.class);

    /**
     * <p>Set operational mode for hot pixel correction.</p>
     * <p>Valid modes for this camera device are listed in
     * {@link CameraCharacteristics#HOT_PIXEL_AVAILABLE_HOT_PIXEL_MODES android.hotPixel.availableHotPixelModes}.</p>
     * <p>Hotpixel correction interpolates out, or otherwise removes, pixels
     * that do not accurately encode the incoming light (i.e. pixels that
     * are stuck at an arbitrary value).</p>
     *
     * @see CameraCharacteristics#HOT_PIXEL_AVAILABLE_HOT_PIXEL_MODES
     * @see #HOT_PIXEL_MODE_OFF
     * @see #HOT_PIXEL_MODE_FAST
     * @see #HOT_PIXEL_MODE_HIGH_QUALITY
     */
    public static final Key<Integer> HOT_PIXEL_MODE =
            new Key<Integer>("android.hotPixel.mode", int.class);

    /**
     * <p>GPS coordinates to include in output JPEG
     * EXIF</p>
     */
    public static final Key<double[]> JPEG_GPS_COORDINATES =
            new Key<double[]>("android.jpeg.gpsCoordinates", double[].class);

    /**
     * <p>32 characters describing GPS algorithm to
     * include in EXIF</p>
     */
    public static final Key<String> JPEG_GPS_PROCESSING_METHOD =
            new Key<String>("android.jpeg.gpsProcessingMethod", String.class);

    /**
     * <p>Time GPS fix was made to include in
     * EXIF</p>
     */
    public static final Key<Long> JPEG_GPS_TIMESTAMP =
            new Key<Long>("android.jpeg.gpsTimestamp", long.class);

    /**
     * <p>Orientation of JPEG image to
     * write</p>
     */
    public static final Key<Integer> JPEG_ORIENTATION =
            new Key<Integer>("android.jpeg.orientation", int.class);

    /**
     * <p>Compression quality of the final JPEG
     * image</p>
     * <p>85-95 is typical usage range</p>
     */
    public static final Key<Byte> JPEG_QUALITY =
            new Key<Byte>("android.jpeg.quality", byte.class);

    /**
     * <p>Compression quality of JPEG
     * thumbnail</p>
     */
    public static final Key<Byte> JPEG_THUMBNAIL_QUALITY =
            new Key<Byte>("android.jpeg.thumbnailQuality", byte.class);

    /**
     * <p>Resolution of embedded JPEG thumbnail</p>
     * <p>When set to (0, 0) value, the JPEG EXIF will not contain thumbnail,
     * but the captured JPEG will still be a valid image.</p>
     * <p>When a jpeg image capture is issued, the thumbnail size selected should have
     * the same aspect ratio as the jpeg image.</p>
     */
    public static final Key<android.hardware.camera2.Size> JPEG_THUMBNAIL_SIZE =
            new Key<android.hardware.camera2.Size>("android.jpeg.thumbnailSize", android.hardware.camera2.Size.class);

    /**
     * <p>The ratio of lens focal length to the effective
     * aperture diameter.</p>
     * <p>This will only be supported on the camera devices that
     * have variable aperture lens. The aperture value can only be
     * one of the values listed in {@link CameraCharacteristics#LENS_INFO_AVAILABLE_APERTURES android.lens.info.availableApertures}.</p>
     * <p>When this is supported and {@link CaptureRequest#CONTROL_AE_MODE android.control.aeMode} is OFF,
     * this can be set along with {@link CaptureRequest#SENSOR_EXPOSURE_TIME android.sensor.exposureTime},
     * {@link CaptureRequest#SENSOR_SENSITIVITY android.sensor.sensitivity}, and {@link CaptureRequest#SENSOR_FRAME_DURATION android.sensor.frameDuration}
     * to achieve manual exposure control.</p>
     * <p>The requested aperture value may take several frames to reach the
     * requested value; the camera device will report the current (intermediate)
     * aperture size in capture result metadata while the aperture is changing.
     * While the aperture is still changing, {@link CaptureResult#LENS_STATE android.lens.state} will be set to MOVING.</p>
     * <p>When this is supported and {@link CaptureRequest#CONTROL_AE_MODE android.control.aeMode} is one of
     * the ON modes, this will be overridden by the camera device
     * auto-exposure algorithm, the overridden values are then provided
     * back to the user in the corresponding result.</p>
     *
     * @see CaptureRequest#CONTROL_AE_MODE
     * @see CameraCharacteristics#LENS_INFO_AVAILABLE_APERTURES
     * @see CaptureResult#LENS_STATE
     * @see CaptureRequest#SENSOR_EXPOSURE_TIME
     * @see CaptureRequest#SENSOR_FRAME_DURATION
     * @see CaptureRequest#SENSOR_SENSITIVITY
     */
    public static final Key<Float> LENS_APERTURE =
            new Key<Float>("android.lens.aperture", float.class);

    /**
     * <p>State of lens neutral density filter(s).</p>
     * <p>This will not be supported on most camera devices. On devices
     * where this is supported, this may only be set to one of the
     * values included in {@link CameraCharacteristics#LENS_INFO_AVAILABLE_FILTER_DENSITIES android.lens.info.availableFilterDensities}.</p>
     * <p>Lens filters are typically used to lower the amount of light the
     * sensor is exposed to (measured in steps of EV). As used here, an EV
     * step is the standard logarithmic representation, which are
     * non-negative, and inversely proportional to the amount of light
     * hitting the sensor.  For example, setting this to 0 would result
     * in no reduction of the incoming light, and setting this to 2 would
     * mean that the filter is set to reduce incoming light by two stops
     * (allowing 1/4 of the prior amount of light to the sensor).</p>
     * <p>It may take several frames before the lens filter density changes
     * to the requested value. While the filter density is still changing,
     * {@link CaptureResult#LENS_STATE android.lens.state} will be set to MOVING.</p>
     *
     * @see CameraCharacteristics#LENS_INFO_AVAILABLE_FILTER_DENSITIES
     * @see CaptureResult#LENS_STATE
     */
    public static final Key<Float> LENS_FILTER_DENSITY =
            new Key<Float>("android.lens.filterDensity", float.class);

    /**
     * <p>The current lens focal length; used for optical zoom.</p>
     * <p>This setting controls the physical focal length of the camera
     * device's lens. Changing the focal length changes the field of
     * view of the camera device, and is usually used for optical zoom.</p>
     * <p>Like {@link CaptureRequest#LENS_FOCUS_DISTANCE android.lens.focusDistance} and {@link CaptureRequest#LENS_APERTURE android.lens.aperture}, this
     * setting won't be applied instantaneously, and it may take several
     * frames before the lens can change to the requested focal length.
     * While the focal length is still changing, {@link CaptureResult#LENS_STATE android.lens.state} will
     * be set to MOVING.</p>
     * <p>This is expected not to be supported on most devices.</p>
     *
     * @see CaptureRequest#LENS_APERTURE
     * @see CaptureRequest#LENS_FOCUS_DISTANCE
     * @see CaptureResult#LENS_STATE
     */
    public static final Key<Float> LENS_FOCAL_LENGTH =
            new Key<Float>("android.lens.focalLength", float.class);

    /**
     * <p>Distance to plane of sharpest focus,
     * measured from frontmost surface of the lens</p>
     * <p>0 means infinity focus. Used value will be clamped
     * to [0, {@link CameraCharacteristics#LENS_INFO_MINIMUM_FOCUS_DISTANCE android.lens.info.minimumFocusDistance}].</p>
     * <p>Like {@link CaptureRequest#LENS_FOCAL_LENGTH android.lens.focalLength}, this setting won't be applied
     * instantaneously, and it may take several frames before the lens
     * can move to the requested focus distance. While the lens is still moving,
     * {@link CaptureResult#LENS_STATE android.lens.state} will be set to MOVING.</p>
     *
     * @see CaptureRequest#LENS_FOCAL_LENGTH
     * @see CameraCharacteristics#LENS_INFO_MINIMUM_FOCUS_DISTANCE
     * @see CaptureResult#LENS_STATE
     */
    public static final Key<Float> LENS_FOCUS_DISTANCE =
            new Key<Float>("android.lens.focusDistance", float.class);

    /**
     * <p>Sets whether the camera device uses optical image stabilization (OIS)
     * when capturing images.</p>
     * <p>OIS is used to compensate for motion blur due to small movements of
     * the camera during capture. Unlike digital image stabilization, OIS makes
     * use of mechanical elements to stabilize the camera sensor, and thus
     * allows for longer exposure times before camera shake becomes
     * apparent.</p>
     * <p>This is not expected to be supported on most devices.</p>
     * @see #LENS_OPTICAL_STABILIZATION_MODE_OFF
     * @see #LENS_OPTICAL_STABILIZATION_MODE_ON
     */
    public static final Key<Integer> LENS_OPTICAL_STABILIZATION_MODE =
            new Key<Integer>("android.lens.opticalStabilizationMode", int.class);

    /**
     * <p>Mode of operation for the noise reduction
     * algorithm</p>
     * <p>Noise filtering control. OFF means no noise reduction
     * will be applied by the camera device.</p>
     * <p>This must be set to a valid mode in
     * {@link CameraCharacteristics#NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES android.noiseReduction.availableNoiseReductionModes}.</p>
     * <p>FAST/HIGH_QUALITY both mean camera device determined noise filtering
     * will be applied. HIGH_QUALITY mode indicates that the camera device
     * will use the highest-quality noise filtering algorithms,
     * even if it slows down capture rate. FAST means the camera device should not
     * slow down capture rate when applying noise filtering.</p>
     *
     * @see CameraCharacteristics#NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES
     * @see #NOISE_REDUCTION_MODE_OFF
     * @see #NOISE_REDUCTION_MODE_FAST
     * @see #NOISE_REDUCTION_MODE_HIGH_QUALITY
     */
    public static final Key<Integer> NOISE_REDUCTION_MODE =
            new Key<Integer>("android.noiseReduction.mode", int.class);

    /**
     * <p>An application-specified ID for the current
     * request. Must be maintained unchanged in output
     * frame</p>
     * @hide
     */
    public static final Key<Integer> REQUEST_ID =
            new Key<Integer>("android.request.id", int.class);

    /**
     * <p>(x, y, width, height).</p>
     * <p>A rectangle with the top-level corner of (x,y) and size
     * (width, height). The region of the sensor that is used for
     * output. Each stream must use this rectangle to produce its
     * output, cropping to a smaller region if necessary to
     * maintain the stream's aspect ratio.</p>
     * <p>HAL2.x uses only (x, y, width)</p>
     * <p>Any additional per-stream cropping must be done to
     * maximize the final pixel area of the stream.</p>
     * <p>For example, if the crop region is set to a 4:3 aspect
     * ratio, then 4:3 streams should use the exact crop
     * region. 16:9 streams should further crop vertically
     * (letterbox).</p>
     * <p>Conversely, if the crop region is set to a 16:9, then 4:3
     * outputs should crop horizontally (pillarbox), and 16:9
     * streams should match exactly. These additional crops must
     * be centered within the crop region.</p>
     * <p>The output streams must maintain square pixels at all
     * times, no matter what the relative aspect ratios of the
     * crop region and the stream are.  Negative values for
     * corner are allowed for raw output if full pixel array is
     * larger than active pixel array. Width and height may be
     * rounded to nearest larger supportable width, especially
     * for raw output, where only a few fixed scales may be
     * possible. The width and height of the crop region cannot
     * be set to be smaller than floor( activeArraySize.width /
     * {@link CameraCharacteristics#SCALER_AVAILABLE_MAX_DIGITAL_ZOOM android.scaler.availableMaxDigitalZoom} ) and floor(
     * activeArraySize.height /
     * {@link CameraCharacteristics#SCALER_AVAILABLE_MAX_DIGITAL_ZOOM android.scaler.availableMaxDigitalZoom}), respectively.</p>
     *
     * @see CameraCharacteristics#SCALER_AVAILABLE_MAX_DIGITAL_ZOOM
     */
    public static final Key<android.graphics.Rect> SCALER_CROP_REGION =
            new Key<android.graphics.Rect>("android.scaler.cropRegion", android.graphics.Rect.class);

    /**
     * <p>Duration each pixel is exposed to
     * light.</p>
     * <p>If the sensor can't expose this exact duration, it should shorten the
     * duration exposed to the nearest possible value (rather than expose longer).</p>
     */
    public static final Key<Long> SENSOR_EXPOSURE_TIME =
            new Key<Long>("android.sensor.exposureTime", long.class);

    /**
     * <p>Duration from start of frame exposure to
     * start of next frame exposure.</p>
     * <p>The maximum frame rate that can be supported by a camera subsystem is
     * a function of many factors:</p>
     * <ul>
     * <li>Requested resolutions of output image streams</li>
     * <li>Availability of binning / skipping modes on the imager</li>
     * <li>The bandwidth of the imager interface</li>
     * <li>The bandwidth of the various ISP processing blocks</li>
     * </ul>
     * <p>Since these factors can vary greatly between different ISPs and
     * sensors, the camera abstraction tries to represent the bandwidth
     * restrictions with as simple a model as possible.</p>
     * <p>The model presented has the following characteristics:</p>
     * <ul>
     * <li>The image sensor is always configured to output the smallest
     * resolution possible given the application's requested output stream
     * sizes.  The smallest resolution is defined as being at least as large
     * as the largest requested output stream size; the camera pipeline must
     * never digitally upsample sensor data when the crop region covers the
     * whole sensor. In general, this means that if only small output stream
     * resolutions are configured, the sensor can provide a higher frame
     * rate.</li>
     * <li>Since any request may use any or all the currently configured
     * output streams, the sensor and ISP must be configured to support
     * scaling a single capture to all the streams at the same time.  This
     * means the camera pipeline must be ready to produce the largest
     * requested output size without any delay.  Therefore, the overall
     * frame rate of a given configured stream set is governed only by the
     * largest requested stream resolution.</li>
     * <li>Using more than one output stream in a request does not affect the
     * frame duration.</li>
     * <li>Certain format-streams may need to do additional background processing
     * before data is consumed/produced by that stream. These processors
     * can run concurrently to the rest of the camera pipeline, but
     * cannot process more than 1 capture at a time.</li>
     * </ul>
     * <p>The necessary information for the application, given the model above,
     * is provided via the {@link CameraCharacteristics#SCALER_AVAILABLE_MIN_FRAME_DURATIONS android.scaler.availableMinFrameDurations} field.
     * These are used to determine the maximum frame rate / minimum frame
     * duration that is possible for a given stream configuration.</p>
     * <p>Specifically, the application can use the following rules to
     * determine the minimum frame duration it can request from the camera
     * device:</p>
     * <ol>
     * <li>Let the set of currently configured input/output streams
     * be called <code>S</code>.</li>
     * <li>Find the minimum frame durations for each stream in <code>S</code>, by
     * looking it up in {@link CameraCharacteristics#SCALER_AVAILABLE_MIN_FRAME_DURATIONS android.scaler.availableMinFrameDurations} (with
     * its respective size/format). Let this set of frame durations be called
     * <code>F</code>.</li>
     * <li>For any given request <code>R</code>, the minimum frame duration allowed
     * for <code>R</code> is the maximum out of all values in <code>F</code>. Let the streams
     * used in <code>R</code> be called <code>S_r</code>.</li>
     * </ol>
     * <p>If none of the streams in <code>S_r</code> have a stall time (listed in
     * {@link CameraCharacteristics#SCALER_AVAILABLE_STALL_DURATIONS android.scaler.availableStallDurations}), then the frame duration in
     * <code>F</code> determines the steady state frame rate that the application will
     * get if it uses <code>R</code> as a repeating request. Let this special kind
     * of request be called <code>Rsimple</code>.</p>
     * <p>A repeating request <code>Rsimple</code> can be <em>occasionally</em> interleaved
     * by a single capture of a new request <code>Rstall</code> (which has at least
     * one in-use stream with a non-0 stall time) and if <code>Rstall</code> has the
     * same minimum frame duration this will not cause a frame rate loss
     * if all buffers from the previous <code>Rstall</code> have already been
     * delivered.</p>
     * <p>For more details about stalling, see
     * {@link CameraCharacteristics#SCALER_AVAILABLE_STALL_DURATIONS android.scaler.availableStallDurations}.</p>
     *
     * @see CameraCharacteristics#SCALER_AVAILABLE_MIN_FRAME_DURATIONS
     * @see CameraCharacteristics#SCALER_AVAILABLE_STALL_DURATIONS
     */
    public static final Key<Long> SENSOR_FRAME_DURATION =
            new Key<Long>("android.sensor.frameDuration", long.class);

    /**
     * <p>Gain applied to image data. Must be
     * implemented through analog gain only if set to values
     * below 'maximum analog sensitivity'.</p>
     * <p>If the sensor can't apply this exact gain, it should lessen the
     * gain to the nearest possible value (rather than gain more).</p>
     * <p>ISO 12232:2006 REI method</p>
     */
    public static final Key<Integer> SENSOR_SENSITIVITY =
            new Key<Integer>("android.sensor.sensitivity", int.class);

    /**
     * <p>A pixel <code>[R, G_even, G_odd, B]</code> that supplies the test pattern
     * when {@link CaptureRequest#SENSOR_TEST_PATTERN_MODE android.sensor.testPatternMode} is SOLID_COLOR.</p>
     * <p>Each color channel is treated as an unsigned 32-bit integer.
     * The camera device then uses the most significant X bits
     * that correspond to how many bits are in its Bayer raw sensor
     * output.</p>
     * <p>For example, a sensor with RAW10 Bayer output would use the
     * 10 most significant bits from each color channel.</p>
     * <p><b>Optional</b> - This value may be {@code null} on some devices.</p>
     *
     * @see CaptureRequest#SENSOR_TEST_PATTERN_MODE
     */
    public static final Key<int[]> SENSOR_TEST_PATTERN_DATA =
            new Key<int[]>("android.sensor.testPatternData", int[].class);

    /**
     * <p>When enabled, the sensor sends a test pattern instead of
     * doing a real exposure from the camera.</p>
     * <p>When a test pattern is enabled, all manual sensor controls specified
     * by android.sensor.* should be ignored. All other controls should
     * work as normal.</p>
     * <p>For example, if manual flash is enabled, flash firing should still
     * occur (and that the test pattern remain unmodified, since the flash
     * would not actually affect it).</p>
     * <p><b>Optional</b> - This value may be {@code null} on some devices.</p>
     * @see #SENSOR_TEST_PATTERN_MODE_OFF
     * @see #SENSOR_TEST_PATTERN_MODE_SOLID_COLOR
     * @see #SENSOR_TEST_PATTERN_MODE_COLOR_BARS
     * @see #SENSOR_TEST_PATTERN_MODE_COLOR_BARS_FADE_TO_GRAY
     * @see #SENSOR_TEST_PATTERN_MODE_PN9
     * @see #SENSOR_TEST_PATTERN_MODE_CUSTOM1
     */
    public static final Key<Integer> SENSOR_TEST_PATTERN_MODE =
            new Key<Integer>("android.sensor.testPatternMode", int.class);

    /**
     * <p>Quality of lens shading correction applied
     * to the image data.</p>
     * <p>When set to OFF mode, no lens shading correction will be applied by the
     * camera device, and an identity lens shading map data will be provided
     * if <code>{@link CaptureRequest#STATISTICS_LENS_SHADING_MAP_MODE android.statistics.lensShadingMapMode} == ON</code>. For example, for lens
     * shading map with size specified as <code>{@link CameraCharacteristics#LENS_INFO_SHADING_MAP_SIZE android.lens.info.shadingMapSize} = [ 4, 3 ]</code>,
     * the output {@link CaptureResult#STATISTICS_LENS_SHADING_MAP android.statistics.lensShadingMap} for this case will be an identity map
     * shown below:</p>
     * <pre><code>[ 1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0,
     * 1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0,
     * 1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0,
     * 1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0,
     * 1.0, 1.0, 1.0, 1.0,   1.0, 1.0, 1.0, 1.0,
     * 1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0 ]
     * </code></pre>
     * <p>When set to other modes, lens shading correction will be applied by the
     * camera device. Applications can request lens shading map data by setting
     * {@link CaptureRequest#STATISTICS_LENS_SHADING_MAP_MODE android.statistics.lensShadingMapMode} to ON, and then the camera device will provide
     * lens shading map data in {@link CaptureResult#STATISTICS_LENS_SHADING_MAP android.statistics.lensShadingMap}, with size specified
     * by {@link CameraCharacteristics#LENS_INFO_SHADING_MAP_SIZE android.lens.info.shadingMapSize}.</p>
     *
     * @see CameraCharacteristics#LENS_INFO_SHADING_MAP_SIZE
     * @see CaptureResult#STATISTICS_LENS_SHADING_MAP
     * @see CaptureRequest#STATISTICS_LENS_SHADING_MAP_MODE
     * @see #SHADING_MODE_OFF
     * @see #SHADING_MODE_FAST
     * @see #SHADING_MODE_HIGH_QUALITY
     */
    public static final Key<Integer> SHADING_MODE =
            new Key<Integer>("android.shading.mode", int.class);

    /**
     * <p>State of the face detector
     * unit</p>
     * <p>Whether face detection is enabled, and whether it
     * should output just the basic fields or the full set of
     * fields. Value must be one of the
     * {@link CameraCharacteristics#STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES android.statistics.info.availableFaceDetectModes}.</p>
     *
     * @see CameraCharacteristics#STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES
     * @see #STATISTICS_FACE_DETECT_MODE_OFF
     * @see #STATISTICS_FACE_DETECT_MODE_SIMPLE
     * @see #STATISTICS_FACE_DETECT_MODE_FULL
     */
    public static final Key<Integer> STATISTICS_FACE_DETECT_MODE =
            new Key<Integer>("android.statistics.faceDetectMode", int.class);

    /**
     * <p>Operating mode for hotpixel map generation.</p>
     * <p>If set to ON, a hotpixel map is returned in {@link CaptureResult#STATISTICS_HOT_PIXEL_MAP android.statistics.hotPixelMap}.
     * If set to OFF, no hotpixel map should be returned.</p>
     * <p>This must be set to a valid mode from {@link CameraCharacteristics#STATISTICS_INFO_AVAILABLE_HOT_PIXEL_MAP_MODES android.statistics.info.availableHotPixelMapModes}.</p>
     *
     * @see CaptureResult#STATISTICS_HOT_PIXEL_MAP
     * @see CameraCharacteristics#STATISTICS_INFO_AVAILABLE_HOT_PIXEL_MAP_MODES
     */
    public static final Key<Boolean> STATISTICS_HOT_PIXEL_MAP_MODE =
            new Key<Boolean>("android.statistics.hotPixelMapMode", boolean.class);

    /**
     * <p>Whether the camera device will output the lens
     * shading map in output result metadata.</p>
     * <p>When set to ON,
     * {@link CaptureResult#STATISTICS_LENS_SHADING_MAP android.statistics.lensShadingMap} must be provided in
     * the output result metadata.</p>
     *
     * @see CaptureResult#STATISTICS_LENS_SHADING_MAP
     * @see #STATISTICS_LENS_SHADING_MAP_MODE_OFF
     * @see #STATISTICS_LENS_SHADING_MAP_MODE_ON
     */
    public static final Key<Integer> STATISTICS_LENS_SHADING_MAP_MODE =
            new Key<Integer>("android.statistics.lensShadingMapMode", int.class);

    /**
     * <p>Tonemapping / contrast / gamma curve for the blue
     * channel, to use when {@link CaptureRequest#TONEMAP_MODE android.tonemap.mode} is
     * CONTRAST_CURVE.</p>
     * <p>See {@link CaptureRequest#TONEMAP_CURVE_RED android.tonemap.curveRed} for more details.</p>
     *
     * @see CaptureRequest#TONEMAP_CURVE_RED
     * @see CaptureRequest#TONEMAP_MODE
     */
    public static final Key<float[]> TONEMAP_CURVE_BLUE =
            new Key<float[]>("android.tonemap.curveBlue", float[].class);

    /**
     * <p>Tonemapping / contrast / gamma curve for the green
     * channel, to use when {@link CaptureRequest#TONEMAP_MODE android.tonemap.mode} is
     * CONTRAST_CURVE.</p>
     * <p>See {@link CaptureRequest#TONEMAP_CURVE_RED android.tonemap.curveRed} for more details.</p>
     *
     * @see CaptureRequest#TONEMAP_CURVE_RED
     * @see CaptureRequest#TONEMAP_MODE
     */
    public static final Key<float[]> TONEMAP_CURVE_GREEN =
            new Key<float[]>("android.tonemap.curveGreen", float[].class);

    /**
     * <p>Tonemapping / contrast / gamma curve for the red
     * channel, to use when {@link CaptureRequest#TONEMAP_MODE android.tonemap.mode} is
     * CONTRAST_CURVE.</p>
     * <p>Each channel's curve is defined by an array of control points:</p>
     * <pre><code>{@link CaptureRequest#TONEMAP_CURVE_RED android.tonemap.curveRed} =
     * [ P0in, P0out, P1in, P1out, P2in, P2out, P3in, P3out, ..., PNin, PNout ]
     * 2 &lt;= N &lt;= {@link CameraCharacteristics#TONEMAP_MAX_CURVE_POINTS android.tonemap.maxCurvePoints}</code></pre>
     * <p>These are sorted in order of increasing <code>Pin</code>; it is always
     * guaranteed that input values 0.0 and 1.0 are included in the list to
     * define a complete mapping. For input values between control points,
     * the camera device must linearly interpolate between the control
     * points.</p>
     * <p>Each curve can have an independent number of points, and the number
     * of points can be less than max (that is, the request doesn't have to
     * always provide a curve with number of points equivalent to
     * {@link CameraCharacteristics#TONEMAP_MAX_CURVE_POINTS android.tonemap.maxCurvePoints}).</p>
     * <p>A few examples, and their corresponding graphical mappings; these
     * only specify the red channel and the precision is limited to 4
     * digits, for conciseness.</p>
     * <p>Linear mapping:</p>
     * <pre><code>{@link CaptureRequest#TONEMAP_CURVE_RED android.tonemap.curveRed} = [ 0, 0, 1.0, 1.0 ]
     * </code></pre>
     * <p><img alt="Linear mapping curve" src="../../../../images/camera2/metadata/android.tonemap.curveRed/linear_tonemap.png" /></p>
     * <p>Invert mapping:</p>
     * <pre><code>{@link CaptureRequest#TONEMAP_CURVE_RED android.tonemap.curveRed} = [ 0, 1.0, 1.0, 0 ]
     * </code></pre>
     * <p><img alt="Inverting mapping curve" src="../../../../images/camera2/metadata/android.tonemap.curveRed/inverse_tonemap.png" /></p>
     * <p>Gamma 1/2.2 mapping, with 16 control points:</p>
     * <pre><code>{@link CaptureRequest#TONEMAP_CURVE_RED android.tonemap.curveRed} = [
     * 0.0000, 0.0000, 0.0667, 0.2920, 0.1333, 0.4002, 0.2000, 0.4812,
     * 0.2667, 0.5484, 0.3333, 0.6069, 0.4000, 0.6594, 0.4667, 0.7072,
     * 0.5333, 0.7515, 0.6000, 0.7928, 0.6667, 0.8317, 0.7333, 0.8685,
     * 0.8000, 0.9035, 0.8667, 0.9370, 0.9333, 0.9691, 1.0000, 1.0000 ]
     * </code></pre>
     * <p><img alt="Gamma = 1/2.2 tonemapping curve" src="../../../../images/camera2/metadata/android.tonemap.curveRed/gamma_tonemap.png" /></p>
     * <p>Standard sRGB gamma mapping, per IEC 61966-2-1:1999, with 16 control points:</p>
     * <pre><code>{@link CaptureRequest#TONEMAP_CURVE_RED android.tonemap.curveRed} = [
     * 0.0000, 0.0000, 0.0667, 0.2864, 0.1333, 0.4007, 0.2000, 0.4845,
     * 0.2667, 0.5532, 0.3333, 0.6125, 0.4000, 0.6652, 0.4667, 0.7130,
     * 0.5333, 0.7569, 0.6000, 0.7977, 0.6667, 0.8360, 0.7333, 0.8721,
     * 0.8000, 0.9063, 0.8667, 0.9389, 0.9333, 0.9701, 1.0000, 1.0000 ]
     * </code></pre>
     * <p><img alt="sRGB tonemapping curve" src="../../../../images/camera2/metadata/android.tonemap.curveRed/srgb_tonemap.png" /></p>
     *
     * @see CaptureRequest#TONEMAP_CURVE_RED
     * @see CameraCharacteristics#TONEMAP_MAX_CURVE_POINTS
     * @see CaptureRequest#TONEMAP_MODE
     */
    public static final Key<float[]> TONEMAP_CURVE_RED =
            new Key<float[]>("android.tonemap.curveRed", float[].class);

    /**
     * <p>High-level global contrast/gamma/tonemapping control.</p>
     * <p>When switching to an application-defined contrast curve by setting
     * {@link CaptureRequest#TONEMAP_MODE android.tonemap.mode} to CONTRAST_CURVE, the curve is defined
     * per-channel with a set of <code>(in, out)</code> points that specify the
     * mapping from input high-bit-depth pixel value to the output
     * low-bit-depth value.  Since the actual pixel ranges of both input
     * and output may change depending on the camera pipeline, the values
     * are specified by normalized floating-point numbers.</p>
     * <p>More-complex color mapping operations such as 3D color look-up
     * tables, selective chroma enhancement, or other non-linear color
     * transforms will be disabled when {@link CaptureRequest#TONEMAP_MODE android.tonemap.mode} is
     * CONTRAST_CURVE.</p>
     * <p>This must be set to a valid mode in
     * {@link CameraCharacteristics#TONEMAP_AVAILABLE_TONE_MAP_MODES android.tonemap.availableToneMapModes}.</p>
     * <p>When using either FAST or HIGH_QUALITY, the camera device will
     * emit its own tonemap curve in {@link CaptureRequest#TONEMAP_CURVE_RED android.tonemap.curveRed},
     * {@link CaptureRequest#TONEMAP_CURVE_GREEN android.tonemap.curveGreen}, and {@link CaptureRequest#TONEMAP_CURVE_BLUE android.tonemap.curveBlue}.
     * These values are always available, and as close as possible to the
     * actually used nonlinear/nonglobal transforms.</p>
     * <p>If a request is sent with TRANSFORM_MATRIX with the camera device's
     * provided curve in FAST or HIGH_QUALITY, the image's tonemap will be
     * roughly the same.</p>
     *
     * @see CameraCharacteristics#TONEMAP_AVAILABLE_TONE_MAP_MODES
     * @see CaptureRequest#TONEMAP_CURVE_BLUE
     * @see CaptureRequest#TONEMAP_CURVE_GREEN
     * @see CaptureRequest#TONEMAP_CURVE_RED
     * @see CaptureRequest#TONEMAP_MODE
     * @see #TONEMAP_MODE_CONTRAST_CURVE
     * @see #TONEMAP_MODE_FAST
     * @see #TONEMAP_MODE_HIGH_QUALITY
     */
    public static final Key<Integer> TONEMAP_MODE =
            new Key<Integer>("android.tonemap.mode", int.class);

    /**
     * <p>This LED is nominally used to indicate to the user
     * that the camera is powered on and may be streaming images back to the
     * Application Processor. In certain rare circumstances, the OS may
     * disable this when video is processed locally and not transmitted to
     * any untrusted applications.</p>
     * <p>In particular, the LED <em>must</em> always be on when the data could be
     * transmitted off the device. The LED <em>should</em> always be on whenever
     * data is stored locally on the device.</p>
     * <p>The LED <em>may</em> be off if a trusted application is using the data that
     * doesn't violate the above rules.</p>
     * @hide
     */
    public static final Key<Boolean> LED_TRANSMIT =
            new Key<Boolean>("android.led.transmit", boolean.class);

    /**
     * <p>Whether black-level compensation is locked
     * to its current values, or is free to vary.</p>
     * <p>When set to ON, the values used for black-level
     * compensation will not change until the lock is set to
     * OFF.</p>
     * <p>Since changes to certain capture parameters (such as
     * exposure time) may require resetting of black level
     * compensation, the camera device must report whether setting
     * the black level lock was successful in the output result
     * metadata.</p>
     * <p>For example, if a sequence of requests is as follows:</p>
     * <ul>
     * <li>Request 1: Exposure = 10ms, Black level lock = OFF</li>
     * <li>Request 2: Exposure = 10ms, Black level lock = ON</li>
     * <li>Request 3: Exposure = 10ms, Black level lock = ON</li>
     * <li>Request 4: Exposure = 20ms, Black level lock = ON</li>
     * <li>Request 5: Exposure = 20ms, Black level lock = ON</li>
     * <li>Request 6: Exposure = 20ms, Black level lock = ON</li>
     * </ul>
     * <p>And the exposure change in Request 4 requires the camera
     * device to reset the black level offsets, then the output
     * result metadata is expected to be:</p>
     * <ul>
     * <li>Result 1: Exposure = 10ms, Black level lock = OFF</li>
     * <li>Result 2: Exposure = 10ms, Black level lock = ON</li>
     * <li>Result 3: Exposure = 10ms, Black level lock = ON</li>
     * <li>Result 4: Exposure = 20ms, Black level lock = OFF</li>
     * <li>Result 5: Exposure = 20ms, Black level lock = ON</li>
     * <li>Result 6: Exposure = 20ms, Black level lock = ON</li>
     * </ul>
     * <p>This indicates to the application that on frame 4, black
     * levels were reset due to exposure value changes, and pixel
     * values may not be consistent across captures.</p>
     * <p>The camera device will maintain the lock to the extent
     * possible, only overriding the lock to OFF when changes to
     * other request parameters require a black level recalculation
     * or reset.</p>
     */
    public static final Key<Boolean> BLACK_LEVEL_LOCK =
            new Key<Boolean>("android.blackLevel.lock", boolean.class);

    /*~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~
     * End generated code
     *~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~@~O@*/
}