/*
 * Copyright (C) 2007 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.NonNull;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.system.ErrnoException;
import android.system.Os;
import android.system.OsConstants;
import android.util.Log;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteOrder;
import java.nio.charset.Charset;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.TimeZone;
import java.util.regex.Pattern;

import libcore.io.IoUtils;
import libcore.io.Streams;

/**
 * This is a class for reading and writing Exif tags in a JPEG file or a RAW image file.
 * <p>
 * Supported formats are: JPEG, DNG, CR2, NEF, NRW, ARW, RW2, ORF and RAF.
 * <p>
 * Attribute mutation is supported for JPEG image files.
 */
public class ExifInterface {
    private static final String TAG = "ExifInterface";
    private static final boolean DEBUG = false;

    // The Exif tag names
    /** Type is String. */
    public static final String TAG_ARTIST = "Artist";
    /** Type is int. */
    public static final String TAG_BITS_PER_SAMPLE = "BitsPerSample";
    /** Type is int. */
    public static final String TAG_COMPRESSION = "Compression";
    /** Type is String. */
    public static final String TAG_COPYRIGHT = "Copyright";
    /** Type is String. */
    public static final String TAG_DATETIME = "DateTime";
    /** Type is String. */
    public static final String TAG_IMAGE_DESCRIPTION = "ImageDescription";
    /** Type is int. */
    public static final String TAG_IMAGE_LENGTH = "ImageLength";
    /** Type is int. */
    public static final String TAG_IMAGE_WIDTH = "ImageWidth";
    /** Type is int. */
    public static final String TAG_JPEG_INTERCHANGE_FORMAT = "JPEGInterchangeFormat";
    /** Type is int. */
    public static final String TAG_JPEG_INTERCHANGE_FORMAT_LENGTH = "JPEGInterchangeFormatLength";
    /** Type is String. */
    public static final String TAG_MAKE = "Make";
    /** Type is String. */
    public static final String TAG_MODEL = "Model";
    /** Type is int. */
    public static final String TAG_ORIENTATION = "Orientation";
    /** Type is int. */
    public static final String TAG_PHOTOMETRIC_INTERPRETATION = "PhotometricInterpretation";
    /** Type is int. */
    public static final String TAG_PLANAR_CONFIGURATION = "PlanarConfiguration";
    /** Type is rational. */
    public static final String TAG_PRIMARY_CHROMATICITIES = "PrimaryChromaticities";
    /** Type is rational. */
    public static final String TAG_REFERENCE_BLACK_WHITE = "ReferenceBlackWhite";
    /** Type is int. */
    public static final String TAG_RESOLUTION_UNIT = "ResolutionUnit";
    /** Type is int. */
    public static final String TAG_ROWS_PER_STRIP = "RowsPerStrip";
    /** Type is int. */
    public static final String TAG_SAMPLES_PER_PIXEL = "SamplesPerPixel";
    /** Type is String. */
    public static final String TAG_SOFTWARE = "Software";
    /** Type is int. */
    public static final String TAG_STRIP_BYTE_COUNTS = "StripByteCounts";
    /** Type is int. */
    public static final String TAG_STRIP_OFFSETS = "StripOffsets";
    /** Type is int. */
    public static final String TAG_TRANSFER_FUNCTION = "TransferFunction";
    /** Type is rational. */
    public static final String TAG_WHITE_POINT = "WhitePoint";
    /** Type is rational. */
    public static final String TAG_X_RESOLUTION = "XResolution";
    /** Type is rational. */
    public static final String TAG_Y_CB_CR_COEFFICIENTS = "YCbCrCoefficients";
    /** Type is int. */
    public static final String TAG_Y_CB_CR_POSITIONING = "YCbCrPositioning";
    /** Type is int. */
    public static final String TAG_Y_CB_CR_SUB_SAMPLING = "YCbCrSubSampling";
    /** Type is rational. */
    public static final String TAG_Y_RESOLUTION = "YResolution";
    /** Type is rational. */
    public static final String TAG_APERTURE_VALUE = "ApertureValue";
    /** Type is rational. */
    public static final String TAG_BRIGHTNESS_VALUE = "BrightnessValue";
    /** Type is String. */
    public static final String TAG_CFA_PATTERN = "CFAPattern";
    /** Type is int. */
    public static final String TAG_COLOR_SPACE = "ColorSpace";
    /** Type is String. */
    public static final String TAG_COMPONENTS_CONFIGURATION = "ComponentsConfiguration";
    /** Type is rational. */
    public static final String TAG_COMPRESSED_BITS_PER_PIXEL = "CompressedBitsPerPixel";
    /** Type is int. */
    public static final String TAG_CONTRAST = "Contrast";
    /** Type is int. */
    public static final String TAG_CUSTOM_RENDERED = "CustomRendered";
    /** Type is String. */
    public static final String TAG_DATETIME_DIGITIZED = "DateTimeDigitized";
    /** Type is String. */
    public static final String TAG_DATETIME_ORIGINAL = "DateTimeOriginal";
    /** Type is String. */
    public static final String TAG_DEVICE_SETTING_DESCRIPTION = "DeviceSettingDescription";
    /** Type is double. */
    public static final String TAG_DIGITAL_ZOOM_RATIO = "DigitalZoomRatio";
    /** Type is String. */
    public static final String TAG_EXIF_VERSION = "ExifVersion";
    /** Type is double. */
    public static final String TAG_EXPOSURE_BIAS_VALUE = "ExposureBiasValue";
    /** Type is rational. */
    public static final String TAG_EXPOSURE_INDEX = "ExposureIndex";
    /** Type is int. */
    public static final String TAG_EXPOSURE_MODE = "ExposureMode";
    /** Type is int. */
    public static final String TAG_EXPOSURE_PROGRAM = "ExposureProgram";
    /** Type is double. */
    public static final String TAG_EXPOSURE_TIME = "ExposureTime";
    /** Type is String. */
    public static final String TAG_F_NUMBER = "FNumber";
    /** Type is String. */
    public static final String TAG_APERTURE = "FNumber";
    /** Type is String. */
    public static final String TAG_FILE_SOURCE = "FileSource";
    /** Type is int. */
    public static final String TAG_FLASH = "Flash";
    /** Type is rational. */
    public static final String TAG_FLASH_ENERGY = "FlashEnergy";
    /** Type is String. */
    public static final String TAG_FLASHPIX_VERSION = "FlashpixVersion";
    /** Type is rational. */
    public static final String TAG_FOCAL_LENGTH = "FocalLength";
    /** Type is int. */
    public static final String TAG_FOCAL_LENGTH_IN_35MM_FILM = "FocalLengthIn35mmFilm";
    /** Type is int. */
    public static final String TAG_FOCAL_PLANE_RESOLUTION_UNIT = "FocalPlaneResolutionUnit";
    /** Type is rational. */
    public static final String TAG_FOCAL_PLANE_X_RESOLUTION = "FocalPlaneXResolution";
    /** Type is rational. */
    public static final String TAG_FOCAL_PLANE_Y_RESOLUTION = "FocalPlaneYResolution";
    /** Type is rational. */
    public static final String TAG_GAIN_CONTROL = "GainControl";
    /** Type is String. */
    public static final String TAG_ISO_SPEED_RATINGS = "ISOSpeedRatings";
    /** Type is String. */
    public static final String TAG_ISO = "ISOSpeedRatings";
    /** Type is String. */
    public static final String TAG_IMAGE_UNIQUE_ID = "ImageUniqueID";
    /** Type is int. */
    public static final String TAG_LIGHT_SOURCE = "LightSource";
    /** Type is String. */
    public static final String TAG_MAKER_NOTE = "MakerNote";
    /** Type is rational. */
    public static final String TAG_MAX_APERTURE_VALUE = "MaxApertureValue";
    /** Type is int. */
    public static final String TAG_METERING_MODE = "MeteringMode";
    /** Type is String. */
    public static final String TAG_OECF = "OECF";
    /** Type is int. */
    public static final String TAG_PIXEL_X_DIMENSION = "PixelXDimension";
    /** Type is int. */
    public static final String TAG_PIXEL_Y_DIMENSION = "PixelYDimension";
    /** Type is String. */
    public static final String TAG_RELATED_SOUND_FILE = "RelatedSoundFile";
    /** Type is int. */
    public static final String TAG_SATURATION = "Saturation";
    /** Type is int. */
    public static final String TAG_SCENE_CAPTURE_TYPE = "SceneCaptureType";
    /** Type is String. */
    public static final String TAG_SCENE_TYPE = "SceneType";
    /** Type is int. */
    public static final String TAG_SENSING_METHOD = "SensingMethod";
    /** Type is int. */
    public static final String TAG_SHARPNESS = "Sharpness";
    /** Type is rational. */
    public static final String TAG_SHUTTER_SPEED_VALUE = "ShutterSpeedValue";
    /** Type is String. */
    public static final String TAG_SPATIAL_FREQUENCY_RESPONSE = "SpatialFrequencyResponse";
    /** Type is String. */
    public static final String TAG_SPECTRAL_SENSITIVITY = "SpectralSensitivity";
    /** Type is int. */
    public static final String TAG_SUBSEC_TIME = "SubSecTime";
    /** Type is int. @hide */
    public static final String TAG_SUBSECTIME = "SubSecTime";
    /** Type is int. */
    public static final String TAG_SUBSEC_TIME_DIGITIZED = "SubSecTimeDigitized";
    /** Type is int. */
    public static final String TAG_SUBSEC_TIME_DIG = "SubSecTimeDigitized";
    /** Type is int. */
    public static final String TAG_SUBSEC_TIME_ORIG = "SubSecTimeOriginal";
    /** Type is int. */
    public static final String TAG_SUBSEC_TIME_ORIGINAL = "SubSecTimeOriginal";
    /** Type is int. */
    public static final String TAG_SUBJECT_AREA = "SubjectArea";
    /** Type is double. */
    public static final String TAG_SUBJECT_DISTANCE = "SubjectDistance";
    /** Type is int. */
    public static final String TAG_SUBJECT_DISTANCE_RANGE = "SubjectDistanceRange";
    /** Type is int. */
    public static final String TAG_SUBJECT_LOCATION = "SubjectLocation";
    /** Type is String. */
    public static final String TAG_USER_COMMENT = "UserComment";
    /** Type is int. */
    public static final String TAG_WHITE_BALANCE = "WhiteBalance";
    /**
     * The altitude (in meters) based on the reference in TAG_GPS_ALTITUDE_REF.
     * Type is rational.
     */
    public static final String TAG_GPS_ALTITUDE = "GPSAltitude";
    /**
     * 0 if the altitude is above sea level. 1 if the altitude is below sea
     * level. Type is int.
     */
    public static final String TAG_GPS_ALTITUDE_REF = "GPSAltitudeRef";
    /** Type is String. */
    public static final String TAG_GPS_AREA_INFORMATION = "GPSAreaInformation";
    /** Type is rational. */
    public static final String TAG_GPS_DOP = "GPSDOP";
    /** Type is String. */
    public static final String TAG_GPS_DATESTAMP = "GPSDateStamp";
    /** Type is rational. */
    public static final String TAG_GPS_DEST_BEARING = "GPSDestBearing";
    /** Type is String. */
    public static final String TAG_GPS_DEST_BEARING_REF = "GPSDestBearingRef";
    /** Type is rational. */
    public static final String TAG_GPS_DEST_DISTANCE = "GPSDestDistance";
    /** Type is String. */
    public static final String TAG_GPS_DEST_DISTANCE_REF = "GPSDestDistanceRef";
    /** Type is rational. */
    public static final String TAG_GPS_DEST_LATITUDE = "GPSDestLatitude";
    /** Type is String. */
    public static final String TAG_GPS_DEST_LATITUDE_REF = "GPSDestLatitudeRef";
    /** Type is rational. */
    public static final String TAG_GPS_DEST_LONGITUDE = "GPSDestLongitude";
    /** Type is String. */
    public static final String TAG_GPS_DEST_LONGITUDE_REF = "GPSDestLongitudeRef";
    /** Type is int. */
    public static final String TAG_GPS_DIFFERENTIAL = "GPSDifferential";
    /** Type is rational. */
    public static final String TAG_GPS_IMG_DIRECTION = "GPSImgDirection";
    /** Type is String. */
    public static final String TAG_GPS_IMG_DIRECTION_REF = "GPSImgDirectionRef";
    /** String. Format is "num1/denom1,num2/denom2,num3/denom3". */
    public static final String TAG_GPS_LATITUDE = "GPSLatitude";
    /** Type is String. */
    public static final String TAG_GPS_LATITUDE_REF = "GPSLatitudeRef";
    /** String. Format is "num1/denom1,num2/denom2,num3/denom3". */
    public static final String TAG_GPS_LONGITUDE = "GPSLongitude";
    /** Type is String. */
    public static final String TAG_GPS_LONGITUDE_REF = "GPSLongitudeRef";
    /** Type is String. */
    public static final String TAG_GPS_MAP_DATUM = "GPSMapDatum";
    /** Type is String. */
    public static final String TAG_GPS_MEASURE_MODE = "GPSMeasureMode";
    /** Type is String. Name of GPS processing method used for location finding. */
    public static final String TAG_GPS_PROCESSING_METHOD = "GPSProcessingMethod";
    /** Type is String. */
    public static final String TAG_GPS_SATELLITES = "GPSSatellites";
    /** Type is rational. */
    public static final String TAG_GPS_SPEED = "GPSSpeed";
    /** Type is String. */
    public static final String TAG_GPS_SPEED_REF = "GPSSpeedRef";
    /** Type is String. */
    public static final String TAG_GPS_STATUS = "GPSStatus";
    /** Type is String. */
    public static final String TAG_GPS_TIMESTAMP = "GPSTimeStamp";
    /** Type is rational. */
    public static final String TAG_GPS_TRACK = "GPSTrack";
    /** Type is String. */
    public static final String TAG_GPS_TRACK_REF = "GPSTrackRef";
    /** Type is String. */
    public static final String TAG_GPS_VERSION_ID = "GPSVersionID";
    /** Type is String. */
    public static final String TAG_INTEROPERABILITY_INDEX = "InteroperabilityIndex";
    /** Type is int. */
    public static final String TAG_THUMBNAIL_IMAGE_LENGTH = "ThumbnailImageLength";
    /** Type is int. */
    public static final String TAG_THUMBNAIL_IMAGE_WIDTH = "ThumbnailImageWidth";

    // Private tags used for pointing the other IFD offset. The types of the following tags are int.
    private static final String TAG_EXIF_IFD_POINTER = "ExifIFDPointer";
    private static final String TAG_GPS_INFO_IFD_POINTER = "GPSInfoIFDPointer";
    private static final String TAG_INTEROPERABILITY_IFD_POINTER = "InteroperabilityIFDPointer";

    // Private tags used for thumbnail information.
    private static final String TAG_HAS_THUMBNAIL = "hasThumbnail";
    private static final String TAG_THUMBNAIL_OFFSET = "thumbnailOffset";
    private static final String TAG_THUMBNAIL_LENGTH = "thumbnailLength";
    private static final String TAG_THUMBNAIL_DATA = "thumbnailData";

    // Constants used for the Orientation Exif tag.
    public static final int ORIENTATION_UNDEFINED = 0;
    public static final int ORIENTATION_NORMAL = 1;
    public static final int ORIENTATION_FLIP_HORIZONTAL = 2;  // left right reversed mirror
    public static final int ORIENTATION_ROTATE_180 = 3;
    public static final int ORIENTATION_FLIP_VERTICAL = 4;  // upside down mirror
    // flipped about top-left <--> bottom-right axis
    public static final int ORIENTATION_TRANSPOSE = 5;
    public static final int ORIENTATION_ROTATE_90 = 6;  // rotate 90 cw to right it
    // flipped about top-right <--> bottom-left axis
    public static final int ORIENTATION_TRANSVERSE = 7;
    public static final int ORIENTATION_ROTATE_270 = 8;  // rotate 270 to right it

    // Constants used for white balance
    public static final int WHITEBALANCE_AUTO = 0;
    public static final int WHITEBALANCE_MANUAL = 1;

    private static final byte[] JPEG_SIGNATURE = new byte[] {(byte) 0xff, (byte) 0xd8, (byte) 0xff};
    private static final int JPEG_SIGNATURE_SIZE = 3;

    private static SimpleDateFormat sFormatter;

    // See Exchangeable image file format for digital still cameras: Exif version 2.2.
    // The following values are for parsing EXIF data area. There are tag groups in EXIF data area.
    // They are called "Image File Directory". They have multiple data formats to cover various
    // image metadata from GPS longitude to camera model name.

    // Types of Exif byte alignments (see JEITA CP-3451 page 10)
    private static final short BYTE_ALIGN_II = 0x4949;  // II: Intel order
    private static final short BYTE_ALIGN_MM = 0x4d4d;  // MM: Motorola order

    // Formats for the value in IFD entry (See TIFF 6.0 spec Types page 15).
    private static final int IFD_FORMAT_BYTE = 1;
    private static final int IFD_FORMAT_STRING = 2;
    private static final int IFD_FORMAT_USHORT = 3;
    private static final int IFD_FORMAT_ULONG = 4;
    private static final int IFD_FORMAT_URATIONAL = 5;
    private static final int IFD_FORMAT_SBYTE = 6;
    private static final int IFD_FORMAT_UNDEFINED = 7;
    private static final int IFD_FORMAT_SSHORT = 8;
    private static final int IFD_FORMAT_SLONG = 9;
    private static final int IFD_FORMAT_SRATIONAL = 10;
    private static final int IFD_FORMAT_SINGLE = 11;
    private static final int IFD_FORMAT_DOUBLE = 12;
    // Sizes of the components of each IFD value format
    private static final int[] IFD_FORMAT_BYTES_PER_FORMAT = new int[] {
            0, 1, 1, 2, 4, 8, 1, 1, 2, 4, 8, 4, 8
    };
    private static final byte[] EXIF_ASCII_PREFIX = new byte[] {
            0x41, 0x53, 0x43, 0x49, 0x49, 0x0, 0x0, 0x0
    };

    // A class for indicating EXIF tag.
    private static class ExifTag {
        public final int number;
        public final String name;

        private ExifTag(String name, int number) {
            this.name = name;
            this.number = number;
        }
    }

    // Primary image IFD TIFF tags (See JEITA CP-3451 Table 14. page 54).
    private static final ExifTag[] IFD_TIFF_TAGS = new ExifTag[] {
            new ExifTag(TAG_IMAGE_WIDTH, 256),
            new ExifTag(TAG_IMAGE_LENGTH, 257),
            new ExifTag(TAG_BITS_PER_SAMPLE, 258),
            new ExifTag(TAG_COMPRESSION, 259),
            new ExifTag(TAG_PHOTOMETRIC_INTERPRETATION, 262),
            new ExifTag(TAG_IMAGE_DESCRIPTION, 270),
            new ExifTag(TAG_MAKE, 271),
            new ExifTag(TAG_MODEL, 272),
            new ExifTag(TAG_STRIP_OFFSETS, 273),
            new ExifTag(TAG_ORIENTATION, 274),
            new ExifTag(TAG_SAMPLES_PER_PIXEL, 277),
            new ExifTag(TAG_ROWS_PER_STRIP, 278),
            new ExifTag(TAG_STRIP_BYTE_COUNTS, 279),
            new ExifTag(TAG_X_RESOLUTION, 282),
            new ExifTag(TAG_Y_RESOLUTION, 283),
            new ExifTag(TAG_PLANAR_CONFIGURATION, 284),
            new ExifTag(TAG_RESOLUTION_UNIT, 296),
            new ExifTag(TAG_TRANSFER_FUNCTION, 301),
            new ExifTag(TAG_SOFTWARE, 305),
            new ExifTag(TAG_DATETIME, 306),
            new ExifTag(TAG_ARTIST, 315),
            new ExifTag(TAG_WHITE_POINT, 318),
            new ExifTag(TAG_PRIMARY_CHROMATICITIES, 319),
            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT, 513),
            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH, 514),
            new ExifTag(TAG_Y_CB_CR_COEFFICIENTS, 529),
            new ExifTag(TAG_Y_CB_CR_SUB_SAMPLING, 530),
            new ExifTag(TAG_Y_CB_CR_POSITIONING, 531),
            new ExifTag(TAG_REFERENCE_BLACK_WHITE, 532),
            new ExifTag(TAG_COPYRIGHT, 33432),
            new ExifTag(TAG_EXIF_IFD_POINTER, 34665),
            new ExifTag(TAG_GPS_INFO_IFD_POINTER, 34853),
    };
    // Primary image IFD Exif Private tags (See JEITA CP-3451 Table 15. page 55).
    private static final ExifTag[] IFD_EXIF_TAGS = new ExifTag[] {
            new ExifTag(TAG_EXPOSURE_TIME, 33434),
            new ExifTag(TAG_F_NUMBER, 33437),
            new ExifTag(TAG_EXPOSURE_PROGRAM, 34850),
            new ExifTag(TAG_SPECTRAL_SENSITIVITY, 34852),
            new ExifTag(TAG_ISO, 34855),
            new ExifTag(TAG_OECF, 34856),
            new ExifTag(TAG_EXIF_VERSION, 36864),
            new ExifTag(TAG_DATETIME_ORIGINAL, 36867),
            new ExifTag(TAG_DATETIME_DIGITIZED, 36868),
            new ExifTag(TAG_COMPONENTS_CONFIGURATION, 37121),
            new ExifTag(TAG_COMPRESSED_BITS_PER_PIXEL, 37122),
            new ExifTag(TAG_SHUTTER_SPEED_VALUE, 37377),
            new ExifTag(TAG_APERTURE_VALUE, 37378),
            new ExifTag(TAG_BRIGHTNESS_VALUE, 37379),
            new ExifTag(TAG_EXPOSURE_BIAS_VALUE, 37380),
            new ExifTag(TAG_MAX_APERTURE_VALUE, 37381),
            new ExifTag(TAG_SUBJECT_DISTANCE, 37382),
            new ExifTag(TAG_METERING_MODE, 37383),
            new ExifTag(TAG_LIGHT_SOURCE, 37384),
            new ExifTag(TAG_FLASH, 37385),
            new ExifTag(TAG_FOCAL_LENGTH, 37386),
            new ExifTag(TAG_SUBJECT_AREA, 37396),
            new ExifTag(TAG_MAKER_NOTE, 37500),
            new ExifTag(TAG_USER_COMMENT, 37510),
            new ExifTag(TAG_SUBSEC_TIME, 37520),
            new ExifTag(TAG_SUBSEC_TIME_ORIG, 37521),
            new ExifTag(TAG_SUBSEC_TIME_DIG, 37522),
            new ExifTag(TAG_FLASHPIX_VERSION, 40960),
            new ExifTag(TAG_COLOR_SPACE, 40961),
            new ExifTag(TAG_PIXEL_X_DIMENSION, 40962),
            new ExifTag(TAG_PIXEL_Y_DIMENSION, 40963),
            new ExifTag(TAG_RELATED_SOUND_FILE, 40964),
            new ExifTag(TAG_INTEROPERABILITY_IFD_POINTER, 40965),
            new ExifTag(TAG_FLASH_ENERGY, 41483),
            new ExifTag(TAG_SPATIAL_FREQUENCY_RESPONSE, 41484),
            new ExifTag(TAG_FOCAL_PLANE_X_RESOLUTION, 41486),
            new ExifTag(TAG_FOCAL_PLANE_Y_RESOLUTION, 41487),
            new ExifTag(TAG_FOCAL_PLANE_RESOLUTION_UNIT, 41488),
            new ExifTag(TAG_SUBJECT_LOCATION, 41492),
            new ExifTag(TAG_EXPOSURE_INDEX, 41493),
            new ExifTag(TAG_SENSING_METHOD, 41495),
            new ExifTag(TAG_FILE_SOURCE, 41728),
            new ExifTag(TAG_SCENE_TYPE, 41729),
            new ExifTag(TAG_CFA_PATTERN, 41730),
            new ExifTag(TAG_CUSTOM_RENDERED, 41985),
            new ExifTag(TAG_EXPOSURE_MODE, 41986),
            new ExifTag(TAG_WHITE_BALANCE, 41987),
            new ExifTag(TAG_DIGITAL_ZOOM_RATIO, 41988),
            new ExifTag(TAG_FOCAL_LENGTH_IN_35MM_FILM, 41989),
            new ExifTag(TAG_SCENE_CAPTURE_TYPE, 41990),
            new ExifTag(TAG_GAIN_CONTROL, 41991),
            new ExifTag(TAG_CONTRAST, 41992),
            new ExifTag(TAG_SATURATION, 41993),
            new ExifTag(TAG_SHARPNESS, 41994),
            new ExifTag(TAG_DEVICE_SETTING_DESCRIPTION, 41995),
            new ExifTag(TAG_SUBJECT_DISTANCE_RANGE, 41996),
            new ExifTag(TAG_IMAGE_UNIQUE_ID, 42016),
    };
    // Primary image IFD GPS Info tags (See JEITA CP-3451 Table 16. page 56).
    private static final ExifTag[] IFD_GPS_TAGS = new ExifTag[] {
            new ExifTag(TAG_GPS_VERSION_ID, 0),
            new ExifTag(TAG_GPS_LATITUDE_REF, 1),
            new ExifTag(TAG_GPS_LATITUDE, 2),
            new ExifTag(TAG_GPS_LONGITUDE_REF, 3),
            new ExifTag(TAG_GPS_LONGITUDE, 4),
            new ExifTag(TAG_GPS_ALTITUDE_REF, 5),
            new ExifTag(TAG_GPS_ALTITUDE, 6),
            new ExifTag(TAG_GPS_TIMESTAMP, 7),
            new ExifTag(TAG_GPS_SATELLITES, 8),
            new ExifTag(TAG_GPS_STATUS, 9),
            new ExifTag(TAG_GPS_MEASURE_MODE, 10),
            new ExifTag(TAG_GPS_DOP, 11),
            new ExifTag(TAG_GPS_SPEED_REF, 12),
            new ExifTag(TAG_GPS_SPEED, 13),
            new ExifTag(TAG_GPS_TRACK_REF, 14),
            new ExifTag(TAG_GPS_TRACK, 15),
            new ExifTag(TAG_GPS_IMG_DIRECTION_REF, 16),
            new ExifTag(TAG_GPS_IMG_DIRECTION, 17),
            new ExifTag(TAG_GPS_MAP_DATUM, 18),
            new ExifTag(TAG_GPS_DEST_LATITUDE_REF, 19),
            new ExifTag(TAG_GPS_DEST_LATITUDE, 20),
            new ExifTag(TAG_GPS_DEST_LONGITUDE_REF, 21),
            new ExifTag(TAG_GPS_DEST_LONGITUDE, 22),
            new ExifTag(TAG_GPS_DEST_BEARING_REF, 23),
            new ExifTag(TAG_GPS_DEST_BEARING, 24),
            new ExifTag(TAG_GPS_DEST_DISTANCE_REF, 25),
            new ExifTag(TAG_GPS_DEST_DISTANCE, 26),
            new ExifTag(TAG_GPS_PROCESSING_METHOD, 27),
            new ExifTag(TAG_GPS_AREA_INFORMATION, 28),
            new ExifTag(TAG_GPS_DATESTAMP, 29),
            new ExifTag(TAG_GPS_DIFFERENTIAL, 30),
    };
    // Primary image IFD Interoperability tag (See JEITA CP-3451 Table 17. page 56).
    private static final ExifTag[] IFD_INTEROPERABILITY_TAGS = new ExifTag[] {
            new ExifTag(TAG_INTEROPERABILITY_INDEX, 1),
    };
    // IFD Thumbnail tags (See JEITA CP-3451 Table 18. page 57).
    private static final ExifTag[] IFD_THUMBNAIL_TAGS = new ExifTag[] {
            new ExifTag(TAG_THUMBNAIL_IMAGE_WIDTH, 256),
            new ExifTag(TAG_THUMBNAIL_IMAGE_LENGTH, 257),
            new ExifTag(TAG_BITS_PER_SAMPLE, 258),
            new ExifTag(TAG_COMPRESSION, 259),
            new ExifTag(TAG_PHOTOMETRIC_INTERPRETATION, 262),
            new ExifTag(TAG_IMAGE_DESCRIPTION, 270),
            new ExifTag(TAG_MAKE, 271),
            new ExifTag(TAG_MODEL, 272),
            new ExifTag(TAG_STRIP_OFFSETS, 273),
            new ExifTag(TAG_ORIENTATION, 274),
            new ExifTag(TAG_SAMPLES_PER_PIXEL, 277),
            new ExifTag(TAG_ROWS_PER_STRIP, 278),
            new ExifTag(TAG_STRIP_BYTE_COUNTS, 279),
            new ExifTag(TAG_X_RESOLUTION, 282),
            new ExifTag(TAG_Y_RESOLUTION, 283),
            new ExifTag(TAG_PLANAR_CONFIGURATION, 284),
            new ExifTag(TAG_RESOLUTION_UNIT, 296),
            new ExifTag(TAG_TRANSFER_FUNCTION, 301),
            new ExifTag(TAG_SOFTWARE, 305),
            new ExifTag(TAG_DATETIME, 306),
            new ExifTag(TAG_ARTIST, 315),
            new ExifTag(TAG_WHITE_POINT, 318),
            new ExifTag(TAG_PRIMARY_CHROMATICITIES, 319),
            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT, 513),
            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH, 514),
            new ExifTag(TAG_Y_CB_CR_COEFFICIENTS, 529),
            new ExifTag(TAG_Y_CB_CR_SUB_SAMPLING, 530),
            new ExifTag(TAG_Y_CB_CR_POSITIONING, 531),
            new ExifTag(TAG_REFERENCE_BLACK_WHITE, 532),
            new ExifTag(TAG_COPYRIGHT, 33432),
            new ExifTag(TAG_EXIF_IFD_POINTER, 34665),
            new ExifTag(TAG_GPS_INFO_IFD_POINTER, 34853),
    };

    // See JEITA CP-3451 Figure 5. page 9.
    // The following values are used for indicating pointers to the other Image File Directorys.

    // Indices of Exif Ifd tag groups
    private static final int IFD_TIFF_HINT = 0;
    private static final int IFD_EXIF_HINT = 1;
    private static final int IFD_GPS_HINT = 2;
    private static final int IFD_INTEROPERABILITY_HINT = 3;
    private static final int IFD_THUMBNAIL_HINT = 4;
    // List of Exif tag groups
    private static final ExifTag[][] EXIF_TAGS = new ExifTag[][] {
            IFD_TIFF_TAGS, IFD_EXIF_TAGS, IFD_GPS_TAGS, IFD_INTEROPERABILITY_TAGS,
            IFD_THUMBNAIL_TAGS
    };
    // List of tags for pointing to the other image file directory offset.
    private static final ExifTag[] IFD_POINTER_TAGS = new ExifTag[] {
            new ExifTag(TAG_EXIF_IFD_POINTER, 34665),
            new ExifTag(TAG_GPS_INFO_IFD_POINTER, 34853),
            new ExifTag(TAG_INTEROPERABILITY_IFD_POINTER, 40965),
    };
    // List of indices of the indicated tag groups according to the IFD_POINTER_TAGS
    private static final int[] IFD_POINTER_TAG_HINTS = new int[] {
            IFD_EXIF_HINT, IFD_GPS_HINT, IFD_INTEROPERABILITY_HINT
    };
    // Tags for indicating the thumbnail offset and length
    private static final ExifTag JPEG_INTERCHANGE_FORMAT_TAG =
            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT, 513);
    private static final ExifTag JPEG_INTERCHANGE_FORMAT_LENGTH_TAG =
            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH, 514);

    // Mappings from tag number to tag name and each item represents one IFD tag group.
    private static final HashMap[] sExifTagMapsForReading = new HashMap[EXIF_TAGS.length];
    // Mappings from tag name to tag number and each item represents one IFD tag group.
    private static final HashMap[] sExifTagMapsForWriting = new HashMap[EXIF_TAGS.length];

    // See JPEG File Interchange Format Version 1.02.
    // The following values are defined for handling JPEG streams. In this implementation, we are
    // not only getting information from EXIF but also from some JPEG special segments such as
    // MARKER_COM for user comment and MARKER_SOFx for image width and height.

    // Identifier for EXIF APP1 segment in JPEG
    private static final byte[] IDENTIFIER_EXIF_APP1 =
            "Exif\0\0".getBytes(Charset.forName("US-ASCII"));
    // JPEG segment markers, that each marker consumes two bytes beginning with 0xff and ending with
    // the indicator. There is no SOF4, SOF8, SOF16 markers in JPEG and SOFx markers indicates start
    // of frame(baseline DCT) and the image size info exists in its beginning part.
    private static final byte MARKER = (byte) 0xff;
    private static final byte MARKER_SOI = (byte) 0xd8;
    private static final byte MARKER_SOF0 = (byte) 0xc0;
    private static final byte MARKER_SOF1 = (byte) 0xc1;
    private static final byte MARKER_SOF2 = (byte) 0xc2;
    private static final byte MARKER_SOF3 = (byte) 0xc3;
    private static final byte MARKER_SOF5 = (byte) 0xc5;
    private static final byte MARKER_SOF6 = (byte) 0xc6;
    private static final byte MARKER_SOF7 = (byte) 0xc7;
    private static final byte MARKER_SOF9 = (byte) 0xc9;
    private static final byte MARKER_SOF10 = (byte) 0xca;
    private static final byte MARKER_SOF11 = (byte) 0xcb;
    private static final byte MARKER_SOF13 = (byte) 0xcd;
    private static final byte MARKER_SOF14 = (byte) 0xce;
    private static final byte MARKER_SOF15 = (byte) 0xcf;
    private static final byte MARKER_SOS = (byte) 0xda;
    private static final byte MARKER_APP1 = (byte) 0xe1;
    private static final byte MARKER_COM = (byte) 0xfe;
    private static final byte MARKER_EOI = (byte) 0xd9;

    static {
        System.loadLibrary("media_jni");
        nativeInitRaw();
        sFormatter = new SimpleDateFormat("yyyy:MM:dd HH:mm:ss");
        sFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));

        // Build up the hash tables to look up Exif tags for reading Exif tags.
        for (int hint = 0; hint < EXIF_TAGS.length; ++hint) {
            sExifTagMapsForReading[hint] = new HashMap();
            sExifTagMapsForWriting[hint] = new HashMap();
            for (ExifTag tag : EXIF_TAGS[hint]) {
                sExifTagMapsForReading[hint].put(tag.number, tag.name);
                sExifTagMapsForWriting[hint].put(tag.name, tag.number);
            }
        }
    }

    private final String mFilename;
    private final FileDescriptor mSeekableFileDescriptor;
    private final AssetManager.AssetInputStream mAssetInputStream;
    private final boolean mIsInputStream;
    private boolean mIsRaw;
    private final HashMap[] mAttributes = new HashMap[EXIF_TAGS.length];
    private boolean mHasThumbnail;
    // The following values used for indicating a thumbnail position.
    private int mThumbnailOffset;
    private int mThumbnailLength;
    private byte[] mThumbnailBytes;

    // Pattern to check non zero timestamp
    private static final Pattern sNonZeroTimePattern = Pattern.compile(".*[1-9].*");

    /**
     * Reads Exif tags from the specified image file.
     */
    public ExifInterface(String filename) throws IOException {
        if (filename == null) {
            throw new IllegalArgumentException("filename cannot be null");
        }
        FileInputStream in = null;
        mAssetInputStream = null;
        mFilename = filename;
        mIsInputStream = false;
        try {
            in = new FileInputStream(filename);
            if (isSeekableFD(in.getFD())) {
                mSeekableFileDescriptor = in.getFD();
            } else {
                mSeekableFileDescriptor = null;
            }
            loadAttributes(in);
        } finally {
            IoUtils.closeQuietly(in);
        }
    }

    /**
     * Reads Exif tags from the specified image file descriptor. Attribute mutation is supported
     * for writable and seekable file descriptors only.
     */
    public ExifInterface(FileDescriptor fileDescriptor) throws IOException {
        if (fileDescriptor == null) {
            throw new IllegalArgumentException("fileDescriptor cannot be null");
        }
        mAssetInputStream = null;
        mFilename = null;
        if (isSeekableFD(fileDescriptor)) {
            mSeekableFileDescriptor = fileDescriptor;
            // Keep the original file descriptor in order to save attributes when it's seekable.
            // Otherwise, just close the given file descriptor after reading it because the save
            // feature won't be working.
            try {
                fileDescriptor = Os.dup(fileDescriptor);
            } catch (ErrnoException e) {
                throw e.rethrowAsIOException();
            }
        } else {
            mSeekableFileDescriptor = null;
        }
        mIsInputStream = false;
        FileInputStream in = null;
        try {
            in = new FileInputStream(fileDescriptor);
            loadAttributes(in);
        } finally {
            IoUtils.closeQuietly(in);
        }
    }

    /**
     * Reads Exif tags from the specified image input stream. Attribute mutation is not supported
     * for input streams.
     */
    public ExifInterface(InputStream inputStream) throws IOException {
        if (inputStream == null) {
            throw new IllegalArgumentException("inputStream cannot be null");
        }
        mFilename = null;
        if (inputStream instanceof AssetManager.AssetInputStream) {
            mAssetInputStream = (AssetManager.AssetInputStream) inputStream;
            mSeekableFileDescriptor = null;
        } else if (inputStream instanceof FileInputStream
                && isSeekableFD(((FileInputStream) inputStream).getFD())) {
            mAssetInputStream = null;
            mSeekableFileDescriptor = ((FileInputStream) inputStream).getFD();
        } else {
            mAssetInputStream = null;
            mSeekableFileDescriptor = null;
        }
        mIsInputStream = true;
        loadAttributes(inputStream);
    }

    /**
     * Returns the value of the specified tag or {@code null} if there
     * is no such tag in the image file.
     *
     * @param tag the name of the tag.
     */
    public String getAttribute(String tag) {
        // Retrieves all tag groups. The value from primary image tag group has a higher priority
        // than the value from the thumbnail tag group if there are more than one candidates.
        for (int i = 0; i < EXIF_TAGS.length; ++i) {
            Object value = mAttributes[i].get(tag);
            if (value != null) {
                return (String) value;
            }
        }
        return null;
    }

    /**
     * Returns the integer value of the specified tag. If there is no such tag
     * in the image file or the value cannot be parsed as integer, return
     * <var>defaultValue</var>.
     *
     * @param tag the name of the tag.
     * @param defaultValue the value to return if the tag is not available.
     */
    public int getAttributeInt(String tag, int defaultValue) {
        String value = getAttribute(tag);
        if (value == null) return defaultValue;
        try {
            return Integer.valueOf(value);
        } catch (NumberFormatException e) {
            return defaultValue;
        }
    }

    /**
     * Returns the double value of the tag that is specified as rational or contains a
     * double-formatted value. If there is no such tag in the image file or the value cannot be
     * parsed as double, return <var>defaultValue</var>.
     *
     * @param tag the name of the tag.
     * @param defaultValue the value to return if the tag is not available.
     */
    public double getAttributeDouble(String tag, double defaultValue) {
        String value = getAttribute(tag);
        if (value == null) return defaultValue;
        try {
            int index = value.indexOf("/");
            if (index == -1) return Double.parseDouble(value);
            double denom = Double.parseDouble(value.substring(index + 1));
            if (denom == 0) return defaultValue;
            double num = Double.parseDouble(value.substring(0, index));
            return num / denom;
        } catch (NumberFormatException e) {
            return defaultValue;
        }
    }

    /**
     * Set the value of the specified tag.
     *
     * @param tag the name of the tag.
     * @param value the value of the tag.
     */
    public void setAttribute(String tag, String value) {
        for (int i = 0 ; i < EXIF_TAGS.length; ++i) {
            if (i == IFD_THUMBNAIL_HINT && !mHasThumbnail) {
                continue;
            }
            if (sExifTagMapsForWriting[i].containsKey(tag)) {
                mAttributes[i].put(tag, value);
            }
        }
    }

    /**
     * Update the values of the tags in the tag groups if any value for the tag already was stored.
     *
     * @param tag the name of the tag.
     * @param value the value of the tag.
     * @return Returns {@code true} if updating is placed.
     */
    private boolean updateAttribute(String tag, String value) {
        boolean updated = false;
        for (int i = 0 ; i < EXIF_TAGS.length; ++i) {
            if (mAttributes[i].containsKey(tag)) {
                mAttributes[i].put(tag, value);
                updated = true;
            }
        }
        return updated;
    }

    /**
     * Remove any values of the specified tag.
     *
     * @param tag the name of the tag.
     */
    private void removeAttribute(String tag) {
        for (int i = 0 ; i < EXIF_TAGS.length; ++i) {
            mAttributes[i].remove(tag);
        }
    }

    /**
     * This function decides which parser to read the image data according to the given input stream
     * type and the content of the input stream. In each case, it reads the first three bytes to
     * determine whether the image data format is JPEG or not.
     */
    private void loadAttributes(@NonNull InputStream in) throws IOException {
        try {
            // Initialize mAttributes.
            for (int i = 0; i < EXIF_TAGS.length; ++i) {
                mAttributes[i] = new HashMap();
            }

            // Process RAW input stream
            if (mAssetInputStream != null) {
                long asset = mAssetInputStream.getNativeAsset();
                if (handleRawResult(nativeGetRawAttributesFromAsset(asset))) {
                    return;
                }
            } else if (mSeekableFileDescriptor != null) {
                if (handleRawResult(nativeGetRawAttributesFromFileDescriptor(
                        mSeekableFileDescriptor))) {
                    return;
                }
            } else {
                in = new BufferedInputStream(in, JPEG_SIGNATURE_SIZE);
                if (!isJpegInputStream((BufferedInputStream) in) && handleRawResult(
                        nativeGetRawAttributesFromInputStream(in))) {
                    return;
                }
            }

            // Process JPEG input stream
            getJpegAttributes(in);
        } catch (IOException e) {
            // Ignore exceptions in order to keep the compatibility with the old versions of
            // ExifInterface.
            Log.w(TAG, "Invalid image: ExifInterface got an unsupported image format file"
                    + "(ExifInterface supports JPEG and some RAW image formats only) "
                    + "or a corrupted JPEG file to ExifInterface.", e);
        } finally {
            if (DEBUG) {
                printAttributes();
            }
        }
    }

    private static boolean isJpegInputStream(BufferedInputStream in) throws IOException {
        in.mark(JPEG_SIGNATURE_SIZE);
        byte[] signatureBytes = new byte[JPEG_SIGNATURE_SIZE];
        if (in.read(signatureBytes) != JPEG_SIGNATURE_SIZE) {
            throw new EOFException();
        }
        boolean isJpeg = Arrays.equals(JPEG_SIGNATURE, signatureBytes);
        in.reset();
        return isJpeg;
    }

    private boolean handleRawResult(HashMap map) {
        if (map == null) {
            return false;
        }

        // Mark for disabling the save feature.
        mIsRaw = true;

        String value = (String) map.remove(TAG_HAS_THUMBNAIL);
        mHasThumbnail = value != null && value.equalsIgnoreCase("true");
        value = (String) map.remove(TAG_THUMBNAIL_OFFSET);
        if (value != null) {
            mThumbnailOffset = Integer.parseInt(value);
        }
        value = (String) map.remove(TAG_THUMBNAIL_LENGTH);
        if (value != null) {
            mThumbnailLength = Integer.parseInt(value);
        }
        mThumbnailBytes = (byte[]) map.remove(TAG_THUMBNAIL_DATA);

        for (Map.Entry entry : (Set<Map.Entry>) map.entrySet()) {
            setAttribute((String) entry.getKey(), (String) entry.getValue());
        }

        return true;
    }

    private static boolean isSeekableFD(FileDescriptor fd) throws IOException {
        try {
            Os.lseek(fd, 0, OsConstants.SEEK_CUR);
            return true;
        } catch (ErrnoException e) {
            return false;
        }
    }

    // Prints out attributes for debugging.
    private void printAttributes() {
        for (int i = 0; i < mAttributes.length; ++i) {
            Log.d(TAG, "The size of tag group[" + i + "]: " + mAttributes[i].size());
            for (Map.Entry entry : (Set<Map.Entry>) mAttributes[i].entrySet()) {
                Log.d(TAG, "tagName: " + entry.getKey() + ", tagValue: " + entry.getValue());
            }
        }
    }

    /**
     * Save the tag data into the original image file. This is expensive because it involves
     * copying all the data from one file to another and deleting the old file and renaming the
     * other. It's best to use {@link #setAttribute(String,String)} to set all attributes to write
     * and make a single call rather than multiple calls for each attribute.
     */
    public void saveAttributes() throws IOException {
        if (mIsRaw) {
            throw new UnsupportedOperationException(
                    "ExifInterface does not support saving attributes on RAW formats.");
        }
        if (mIsInputStream || (mSeekableFileDescriptor == null && mFilename == null)) {
            throw new UnsupportedOperationException(
                    "ExifInterface does not support saving attributes for the current input.");
        }

        // Keep the thumbnail in memory
        mThumbnailBytes = getThumbnail();

        FileInputStream in = null;
        FileOutputStream out = null;
        File tempFile = null;
        try {
            // Move the original file to temporary file.
            if (mFilename != null) {
                tempFile = new File(mFilename + ".tmp");
                File originalFile = new File(mFilename);
                if (!originalFile.renameTo(tempFile)) {
                    throw new IOException("Could'nt rename to " + tempFile.getAbsolutePath());
                }
            } else if (mSeekableFileDescriptor != null) {
                tempFile = File.createTempFile("temp", "jpg");
                Os.lseek(mSeekableFileDescriptor, 0, OsConstants.SEEK_SET);
                in = new FileInputStream(mSeekableFileDescriptor);
                out = new FileOutputStream(tempFile);
                Streams.copy(in, out);
            }
        } catch (ErrnoException e) {
            throw e.rethrowAsIOException();
        } finally {
            IoUtils.closeQuietly(in);
            IoUtils.closeQuietly(out);
        }

        in = null;
        out = null;
        try {
            // Save the new file.
            in = new FileInputStream(tempFile);
            if (mFilename != null) {
                out = new FileOutputStream(mFilename);
            } else if (mSeekableFileDescriptor != null) {
                Os.lseek(mSeekableFileDescriptor, 0, OsConstants.SEEK_SET);
                out = new FileOutputStream(mSeekableFileDescriptor);
            }
            saveJpegAttributes(in, out);
        } catch (ErrnoException e) {
            throw e.rethrowAsIOException();
        } finally {
            IoUtils.closeQuietly(in);
            IoUtils.closeQuietly(out);
            tempFile.delete();
        }

        // Discard the thumbnail in memory
        mThumbnailBytes = null;
    }

    /**
     * Returns true if the image file has a thumbnail.
     */
    public boolean hasThumbnail() {
        return mHasThumbnail;
    }

    /**
     * Returns the thumbnail inside the image file, or {@code null} if there is no thumbnail.
     * The returned data is in JPEG format and can be decoded using
     * {@link android.graphics.BitmapFactory#decodeByteArray(byte[],int,int)}
     */
    public byte[] getThumbnail() {
        if (!mHasThumbnail) {
            return null;
        }
        if (mThumbnailBytes != null) {
            return mThumbnailBytes;
        }

        // Read the thumbnail.
        FileInputStream in = null;
        try {
            if (mAssetInputStream != null) {
                return nativeGetThumbnailFromAsset(
                        mAssetInputStream.getNativeAsset(), mThumbnailOffset, mThumbnailLength);
            } else if (mFilename != null) {
                in = new FileInputStream(mFilename);
            } else if (mSeekableFileDescriptor != null) {
                FileDescriptor fileDescriptor = Os.dup(mSeekableFileDescriptor);
                Os.lseek(fileDescriptor, 0, OsConstants.SEEK_SET);
                in = new FileInputStream(fileDescriptor);
            }
            if (in == null) {
                // Should not be reached this.
                throw new FileNotFoundException();
            }
            if (in.skip(mThumbnailOffset) != mThumbnailOffset) {
                throw new IOException("Corrupted image");
            }
            byte[] buffer = new byte[mThumbnailLength];
            if (in.read(buffer) != mThumbnailLength) {
                throw new IOException("Corrupted image");
            }
            return buffer;
        } catch (IOException | ErrnoException e) {
            // Couldn't get a thumbnail image.
        } finally {
            IoUtils.closeQuietly(in);
        }
        return null;
    }

    /**
     * Returns the offset and length of thumbnail inside the image file, or
     * {@code null} if there is no thumbnail.
     *
     * @return two-element array, the offset in the first value, and length in
     *         the second, or {@code null} if no thumbnail was found.
     * @hide
     */
    public long[] getThumbnailRange() {
        long[] range = new long[2];
        range[0] = mThumbnailOffset;
        range[1] = mThumbnailLength;
        return range;
    }

    /**
     * Stores the latitude and longitude value in a float array. The first element is
     * the latitude, and the second element is the longitude. Returns false if the
     * Exif tags are not available.
     */
    public boolean getLatLong(float output[]) {
        String latValue = getAttribute(TAG_GPS_LATITUDE);
        String latRef = getAttribute(TAG_GPS_LATITUDE_REF);
        String lngValue = getAttribute(TAG_GPS_LONGITUDE);
        String lngRef = getAttribute(TAG_GPS_LONGITUDE_REF);

        if (latValue != null && latRef != null && lngValue != null && lngRef != null) {
            try {
                output[0] = convertRationalLatLonToFloat(latValue, latRef);
                output[1] = convertRationalLatLonToFloat(lngValue, lngRef);
                return true;
            } catch (IllegalArgumentException e) {
                // if values are not parseable
            }
        }

        return false;
    }

    /**
     * Return the altitude in meters. If the exif tag does not exist, return
     * <var>defaultValue</var>.
     *
     * @param defaultValue the value to return if the tag is not available.
     */
    public double getAltitude(double defaultValue) {
        double altitude = getAttributeDouble(TAG_GPS_ALTITUDE, -1);
        int ref = getAttributeInt(TAG_GPS_ALTITUDE_REF, -1);

        if (altitude >= 0 && ref >= 0) {
            return (altitude * ((ref == 1) ? -1 : 1));
        } else {
            return defaultValue;
        }
    }

    /**
     * Returns number of milliseconds since Jan. 1, 1970, midnight local time.
     * Returns -1 if the date time information if not available.
     * @hide
     */
    public long getDateTime() {
        String dateTimeString = getAttribute(TAG_DATETIME);
        if (dateTimeString == null
                || !sNonZeroTimePattern.matcher(dateTimeString).matches()) return -1;

        ParsePosition pos = new ParsePosition(0);
        try {
            // The exif field is in local time. Parsing it as if it is UTC will yield time
            // since 1/1/1970 local time
            Date datetime = sFormatter.parse(dateTimeString, pos);
            if (datetime == null) return -1;
            long msecs = datetime.getTime();

            String subSecs = getAttribute(TAG_SUBSECTIME);
            if (subSecs != null) {
                try {
                    long sub = Long.valueOf(subSecs);
                    while (sub > 1000) {
                        sub /= 10;
                    }
                    msecs += sub;
                } catch (NumberFormatException e) {
                    // Ignored
                }
            }
            return msecs;
        } catch (IllegalArgumentException e) {
            return -1;
        }
    }

    /**
     * Returns number of milliseconds since Jan. 1, 1970, midnight UTC.
     * Returns -1 if the date time information if not available.
     * @hide
     */
    public long getGpsDateTime() {
        String date = getAttribute(TAG_GPS_DATESTAMP);
        String time = getAttribute(TAG_GPS_TIMESTAMP);
        if (date == null || time == null
                || (!sNonZeroTimePattern.matcher(date).matches()
                && !sNonZeroTimePattern.matcher(time).matches())) {
            return -1;
        }

        String dateTimeString = date + ' ' + time;

        ParsePosition pos = new ParsePosition(0);
        try {
            Date datetime = sFormatter.parse(dateTimeString, pos);
            if (datetime == null) return -1;
            return datetime.getTime();
        } catch (IllegalArgumentException e) {
            return -1;
        }
    }

    private static float convertRationalLatLonToFloat(String rationalString, String ref) {
        try {
            String [] parts = rationalString.split(",");

            String [] pair;
            pair = parts[0].split("/");
            double degrees = Double.parseDouble(pair[0].trim())
                    / Double.parseDouble(pair[1].trim());

            pair = parts[1].split("/");
            double minutes = Double.parseDouble(pair[0].trim())
                    / Double.parseDouble(pair[1].trim());

            pair = parts[2].split("/");
            double seconds = Double.parseDouble(pair[0].trim())
                    / Double.parseDouble(pair[1].trim());

            double result = degrees + (minutes / 60.0) + (seconds / 3600.0);
            if ((ref.equals("S") || ref.equals("W"))) {
                return (float) -result;
            }
            return (float) result;
        } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
            // Not valid
            throw new IllegalArgumentException();
        }
    }

    // Loads EXIF attributes from a JPEG input stream.
    private void getJpegAttributes(InputStream inputStream) throws IOException {
        // See JPEG File Interchange Format Specification page 5.
        if (DEBUG) {
            Log.d(TAG, "getJpegAttributes starting with: " + inputStream);
        }
        DataInputStream dataInputStream = new DataInputStream(inputStream);
        byte marker;
        int bytesRead = 0;
        if ((marker = dataInputStream.readByte()) != MARKER) {
            throw new IOException("Invalid marker: " + Integer.toHexString(marker & 0xff));
        }
        ++bytesRead;
        if (dataInputStream.readByte() != MARKER_SOI) {
            throw new IOException("Invalid marker: " + Integer.toHexString(marker & 0xff));
        }
        ++bytesRead;
        while (true) {
            marker = dataInputStream.readByte();
            if (marker != MARKER) {
                throw new IOException("Invalid marker:" + Integer.toHexString(marker & 0xff));
            }
            ++bytesRead;
            marker = dataInputStream.readByte();
            if (DEBUG) {
                Log.d(TAG, "Found JPEG segment indicator: " + Integer.toHexString(marker & 0xff));
            }
            ++bytesRead;

            // EOI indicates the end of an image and in case of SOS, JPEG image stream starts and
            // the image data will terminate right after.
            if (marker == MARKER_EOI || marker == MARKER_SOS) {
                break;
            }
            int length = dataInputStream.readUnsignedShort() - 2;
            bytesRead += 2;
            if (DEBUG) {
                Log.d(TAG, "JPEG segment: " + Integer.toHexString(marker & 0xff) + " (length: "
                        + (length + 2) + ")");
            }
            if (length < 0) {
                throw new IOException("Invalid length");
            }
            switch (marker) {
                case MARKER_APP1: {
                    if (DEBUG) {
                        Log.d(TAG, "MARKER_APP1");
                    }
                    if (length < 6) {
                        // Skip if it's not an EXIF APP1 segment.
                        break;
                    }
                    byte[] identifier = new byte[6];
                    if (inputStream.read(identifier) != 6) {
                        throw new IOException("Invalid exif");
                    }
                    bytesRead += 6;
                    length -= 6;
                    if (!Arrays.equals(identifier, IDENTIFIER_EXIF_APP1)) {
                        // Skip if it's not an EXIF APP1 segment.
                        break;
                    }
                    if (length <= 0) {
                        throw new IOException("Invalid exif");
                    }
                    if (DEBUG) {
                        Log.d(TAG, "readExifSegment with a byte array (length: " + length + ")");
                    }
                    byte[] bytes = new byte[length];
                    if (dataInputStream.read(bytes) != length) {
                        throw new IOException("Invalid exif");
                    }
                    readExifSegment(bytes, bytesRead);
                    bytesRead += length;
                    length = 0;
                    break;
                }

                case MARKER_COM: {
                    byte[] bytes = new byte[length];
                    if (dataInputStream.read(bytes) != length) {
                        throw new IOException("Invalid exif");
                    }
                    length = 0;
                    mAttributes[IFD_EXIF_HINT].put(TAG_USER_COMMENT,
                            new String(bytes, Charset.forName("US-ASCII")));
                    break;
                }

                case MARKER_SOF0:
                case MARKER_SOF1:
                case MARKER_SOF2:
                case MARKER_SOF3:
                case MARKER_SOF5:
                case MARKER_SOF6:
                case MARKER_SOF7:
                case MARKER_SOF9:
                case MARKER_SOF10:
                case MARKER_SOF11:
                case MARKER_SOF13:
                case MARKER_SOF14:
                case MARKER_SOF15: {
                    if (dataInputStream.skipBytes(1) != 1) {
                        throw new IOException("Invalid SOFx");
                    }
                    mAttributes[IFD_TIFF_HINT].put(TAG_IMAGE_LENGTH,
                            String.valueOf(dataInputStream.readUnsignedShort()));
                    mAttributes[IFD_TIFF_HINT].put(TAG_IMAGE_WIDTH,
                            String.valueOf(dataInputStream.readUnsignedShort()));
                    length -= 5;
                    break;
                }

                default: {
                    break;
                }
            }
            if (length < 0) {
                throw new IOException("Invalid length");
            }
            if (dataInputStream.skipBytes(length) != length) {
                throw new IOException("Invalid JPEG segment");
            }
            bytesRead += length;
        }
    }

    // Stores a new JPEG image with EXIF attributes into a given output stream.
    private void saveJpegAttributes(InputStream inputStream, OutputStream outputStream)
            throws IOException {
        // See JPEG File Interchange Format Specification page 5.
        if (DEBUG) {
            Log.d(TAG, "saveJpegAttributes starting with (inputStream: " + inputStream
                    + ", outputStream: " + outputStream + ")");
        }
        DataInputStream dataInputStream = new DataInputStream(inputStream);
        ExifDataOutputStream dataOutputStream = new ExifDataOutputStream(outputStream);
        if (dataInputStream.readByte() != MARKER) {
            throw new IOException("Invalid marker");
        }
        dataOutputStream.writeByte(MARKER);
        if (dataInputStream.readByte() != MARKER_SOI) {
            throw new IOException("Invalid marker");
        }
        dataOutputStream.writeByte(MARKER_SOI);

        // Write EXIF APP1 segment
        dataOutputStream.writeByte(MARKER);
        dataOutputStream.writeByte(MARKER_APP1);
        writeExifSegment(dataOutputStream, 6);

        byte[] bytes = new byte[4096];

        while (true) {
            byte marker = dataInputStream.readByte();
            if (marker != MARKER) {
                throw new IOException("Invalid marker");
            }
            marker = dataInputStream.readByte();
            switch (marker) {
                case MARKER_APP1: {
                    int length = dataInputStream.readUnsignedShort() - 2;
                    if (length < 0) {
                        throw new IOException("Invalid length");
                    }
                    byte[] identifier = new byte[6];
                    if (length >= 6) {
                        if (dataInputStream.read(identifier) != 6) {
                            throw new IOException("Invalid exif");
                        }
                        if (Arrays.equals(identifier, IDENTIFIER_EXIF_APP1)) {
                            // Skip the original EXIF APP1 segment.
                            if (dataInputStream.skip(length - 6) != length - 6) {
                                throw new IOException("Invalid length");
                            }
                            break;
                        }
                    }
                    // Copy non-EXIF APP1 segment.
                    dataOutputStream.writeByte(MARKER);
                    dataOutputStream.writeByte(marker);
                    dataOutputStream.writeUnsignedShort(length + 2);
                    if (length >= 6) {
                        length -= 6;
                        dataOutputStream.write(identifier);
                    }
                    int read;
                    while (length > 0 && (read = dataInputStream.read(
                            bytes, 0, Math.min(length, bytes.length))) >= 0) {
                        dataOutputStream.write(bytes, 0, read);
                        length -= read;
                    }
                    break;
                }
                case MARKER_EOI:
                case MARKER_SOS: {
                    dataOutputStream.writeByte(MARKER);
                    dataOutputStream.writeByte(marker);
                    // Copy all the remaining data
                    Streams.copy(dataInputStream, dataOutputStream);
                    return;
                }
                default: {
                    // Copy JPEG segment
                    dataOutputStream.writeByte(MARKER);
                    dataOutputStream.writeByte(marker);
                    int length = dataInputStream.readUnsignedShort();
                    dataOutputStream.writeUnsignedShort(length);
                    length -= 2;
                    if (length < 0) {
                        throw new IOException("Invalid length");
                    }
                    int read;
                    while (length > 0 && (read = dataInputStream.read(
                            bytes, 0, Math.min(length, bytes.length))) >= 0) {
                        dataOutputStream.write(bytes, 0, read);
                        length -= read;
                    }
                    break;
                }
            }
        }
    }

    // Reads the given EXIF byte area and save its tag data into attributes.
    private void readExifSegment(byte[] exifBytes, int exifOffsetFromBeginning) throws IOException {
        // Parse TIFF Headers. See JEITA CP-3451C Table 1. page 10.
        ByteOrderAwarenessDataInputStream dataInputStream =
                new ByteOrderAwarenessDataInputStream(exifBytes);

        // Read byte align
        short byteOrder = dataInputStream.readShort();
        switch (byteOrder) {
            case BYTE_ALIGN_II:
                if (DEBUG) {
                    Log.d(TAG, "readExifSegment: Byte Align II");
                }
                dataInputStream.setByteOrder(ByteOrder.LITTLE_ENDIAN);
                break;
            case BYTE_ALIGN_MM:
                if (DEBUG) {
                    Log.d(TAG, "readExifSegment: Byte Align MM");
                }
                dataInputStream.setByteOrder(ByteOrder.BIG_ENDIAN);
                break;
            default:
                throw new IOException("Invalid byte order: " + Integer.toHexString(byteOrder));
        }

        int startCode = dataInputStream.readUnsignedShort();
        if (startCode != 0x2a) {
            throw new IOException("Invalid exif start: " + Integer.toHexString(startCode));
        }

        // Read first ifd offset
        long firstIfdOffset = dataInputStream.readUnsignedInt();
        if (firstIfdOffset < 8 || firstIfdOffset >= exifBytes.length) {
            throw new IOException("Invalid first Ifd offset: " + firstIfdOffset);
        }
        firstIfdOffset -= 8;
        if (firstIfdOffset > 0) {
            if (dataInputStream.skip(firstIfdOffset) != firstIfdOffset) {
                throw new IOException("Couldn't jump to first Ifd: " + firstIfdOffset);
            }
        }

        // Read primary image TIFF image file directory.
        readImageFileDirectory(dataInputStream, IFD_TIFF_HINT);

        // Process thumbnail.
        String jpegInterchangeFormatString = getAttribute(JPEG_INTERCHANGE_FORMAT_TAG.name);
        String jpegInterchangeFormatLengthString =
                getAttribute(JPEG_INTERCHANGE_FORMAT_LENGTH_TAG.name);
        if (jpegInterchangeFormatString != null && jpegInterchangeFormatLengthString != null) {
            try {
                int jpegInterchangeFormat = Integer.parseInt(jpegInterchangeFormatString);
                int jpegInterchangeFormatLength = Integer
                        .parseInt(jpegInterchangeFormatLengthString);
                // The following code limits the size of thumbnail size not to overflow EXIF data area.
                jpegInterchangeFormatLength = Math.min(jpegInterchangeFormat
                        + jpegInterchangeFormatLength, exifOffsetFromBeginning + exifBytes.length)
                        - jpegInterchangeFormat;
                if (jpegInterchangeFormat > 0 && jpegInterchangeFormatLength > 0) {
                    mHasThumbnail = true;
                    mThumbnailOffset = exifOffsetFromBeginning + jpegInterchangeFormat;
                    mThumbnailLength = jpegInterchangeFormatLength;

                    if (mFilename == null && mAssetInputStream == null
                            && mSeekableFileDescriptor == null) {
                        // Save the thumbnail in memory if the input doesn't support reading again.
                        byte[] thumbnailBytes = new byte[jpegInterchangeFormatLength];
                        dataInputStream.seek(jpegInterchangeFormat);
                        dataInputStream.readFully(thumbnailBytes);
                        mThumbnailBytes = thumbnailBytes;

                        if (DEBUG) {
                            Bitmap bitmap = BitmapFactory.decodeByteArray(
                                    thumbnailBytes, 0, thumbnailBytes.length);
                            Log.d(TAG, "Thumbnail offset: " + mThumbnailOffset + ", length: "
                                    + mThumbnailLength + ", width: " + bitmap.getWidth()
                                    + ", height: "
                                    + bitmap.getHeight());
                        }
                    }
                }
            } catch (NumberFormatException e) {
                // Ignored the corrupted image.
            }
        }

        // For compatibility, keep data formats as follows.
        convertToInt(TAG_IMAGE_WIDTH);
        convertToInt(TAG_IMAGE_LENGTH);
        convertToInt(TAG_ORIENTATION);
        convertToInt(TAG_FLASH);
        convertToRational(TAG_FOCAL_LENGTH);
        convertToDouble(TAG_DIGITAL_ZOOM_RATIO);
        convertToDouble(TAG_EXPOSURE_TIME);
        convertToDouble(TAG_F_NUMBER);
        convertToDouble(TAG_SUBJECT_DISTANCE);
        convertToInt(TAG_ISO);
        convertToDouble(TAG_EXPOSURE_BIAS_VALUE);
        convertToInt(TAG_WHITE_BALANCE);
        convertToInt(TAG_LIGHT_SOURCE);
        convertToInt(TAG_METERING_MODE);
        convertToInt(TAG_EXPOSURE_PROGRAM);
        convertToInt(TAG_EXPOSURE_MODE);
        convertToRational(TAG_GPS_ALTITUDE);
        convertToInt(TAG_GPS_ALTITUDE_REF);
        convertToRational(TAG_GPS_LONGITUDE);
        convertToRational(TAG_GPS_LATITUDE);
        convertToTimestamp(TAG_GPS_TIMESTAMP);

        // The value of DATETIME tag has the same value of DATETIME_ORIGINAL tag.
        String valueOfDateTimeOriginal = getAttribute(TAG_DATETIME_ORIGINAL);
        if (valueOfDateTimeOriginal != null) {
            mAttributes[IFD_TIFF_HINT].put(TAG_DATETIME, valueOfDateTimeOriginal);
        }

        // Add the default value.
        if (getAttribute(TAG_IMAGE_WIDTH) == null) {
            mAttributes[IFD_TIFF_HINT].put(TAG_IMAGE_WIDTH, "0");
        }
        if (getAttribute(TAG_IMAGE_LENGTH) == null) {
            mAttributes[IFD_TIFF_HINT].put(TAG_IMAGE_LENGTH, "0");
        }
        if (getAttribute(TAG_ORIENTATION) == null) {
            mAttributes[IFD_TIFF_HINT].put(TAG_ORIENTATION, "0");
        }
        if (getAttribute(TAG_LIGHT_SOURCE) == null) {
            mAttributes[IFD_EXIF_HINT].put(TAG_LIGHT_SOURCE, "0");
        }
    }

    // Converts the tag value to timestamp; Otherwise deletes the given tag.
    private void convertToTimestamp(String tagName) {
        String entryValue = getAttribute(tagName);
        if (entryValue == null) return;
        int dataFormat = getDataFormatOfExifEntryValue(entryValue);
        String[] components = entryValue.split(",");
        if (dataFormat == IFD_FORMAT_SRATIONAL && components.length == 3) {
            StringBuilder stringBuilder = new StringBuilder();
            for (String component : components) {
                if (stringBuilder.length() > 0) {
                    stringBuilder.append(":");
                }
                String[] rationalNumber = component.split("/");
                int numerator = Integer.parseInt(rationalNumber[0]);
                int denominator = Integer.parseInt(rationalNumber[1]);
                if (denominator == 0) {
                    numerator = 0;
                    denominator = 1;
                }
                int value = numerator / denominator;
                stringBuilder.append(String.format("%02d", value));
            }
            updateAttribute(tagName, stringBuilder.toString());
        } else if (dataFormat != IFD_FORMAT_STRING) {
            removeAttribute(tagName);
        }
    }

    // Checks the tag value of a given tag formatted in double type; Otherwise try to convert it to
    // double type or delete it.
    private void convertToDouble(String tagName) {
        String entryValue = getAttribute(tagName);
        if (entryValue == null) return;
        int dataFormat = getDataFormatOfExifEntryValue(entryValue);
        switch (dataFormat) {
            case IFD_FORMAT_SRATIONAL: {
                StringBuilder stringBuilder = new StringBuilder();
                String[] components = entryValue.split(",");
                for (String component : components) {
                    if (stringBuilder.length() > 0) {
                        stringBuilder.append(",");
                    }
                    String[] rationalNumber = component.split("/");
                    int numerator = Integer.parseInt(rationalNumber[0]);
                    int denominator = Integer.parseInt(rationalNumber[1]);
                    if (denominator == 0) {
                        numerator = 0;
                        denominator = 1;
                    }
                    stringBuilder.append((double) numerator / denominator);
                }
                updateAttribute(tagName, stringBuilder.toString());
                break;
            }
            case IFD_FORMAT_DOUBLE:
                // Keep it as is.
                break;
            default:
                removeAttribute(tagName);
                break;
        }
    }

    // Checks the tag value of a given tag formatted in int type; Otherwise deletes the tag value.
    private void convertToRational(String tagName) {
        String entryValue = getAttribute(tagName);
        if (entryValue == null) return;
        int dataFormat = getDataFormatOfExifEntryValue(entryValue);
        switch (dataFormat) {
            case IFD_FORMAT_SLONG:
            case IFD_FORMAT_DOUBLE: {
                StringBuilder stringBuilder = new StringBuilder();
                String[] components = entryValue.split(",");
                for (String component : components) {
                    if (stringBuilder.length() > 0) {
                        stringBuilder.append(",");
                    }
                    double doubleValue = Double.parseDouble(component);
                    stringBuilder.append((int) (doubleValue * 10000.0)).append("/").append(10000);
                }
                updateAttribute(tagName, stringBuilder.toString());
                break;
            }
            case IFD_FORMAT_SRATIONAL:
                // Keep it as is.
                break;
            default:
                removeAttribute(tagName);
                break;
        }
    }

    // Checks the tag value of a given tag formatted in int type; Otherwise deletes the tag value.
    private void convertToInt(String tagName) {
        String entryValue = getAttribute(tagName);
        if (entryValue == null) return;
        int dataFormat = getDataFormatOfExifEntryValue(entryValue);
        if (dataFormat != IFD_FORMAT_SLONG) {
            removeAttribute(tagName);
        }
    }

    // Reads image file directory, which is a tag group in EXIF.
    private void readImageFileDirectory(ByteOrderAwarenessDataInputStream dataInputStream, int hint)
            throws IOException {
        if (dataInputStream.peek() + 2 > dataInputStream.mLength) {
            // Return if there is no data from the offset.
            return;
        }
        // See JEITA CP-3451 Figure 5. page 9.
        short numberOfDirectoryEntry = dataInputStream.readShort();
        if (dataInputStream.peek() + 12 * numberOfDirectoryEntry > dataInputStream.mLength) {
            // Return if the size of entries is too big.
            return;
        }

        if (DEBUG) {
            Log.d(TAG, "numberOfDirectoryEntry: " + numberOfDirectoryEntry);
        }

        for (short i = 0; i < numberOfDirectoryEntry; ++i) {
            int tagNumber = dataInputStream.readUnsignedShort();
            int dataFormat = dataInputStream.readUnsignedShort();
            int numberOfComponents = dataInputStream.readInt();
            long nextEntryOffset = dataInputStream.peek() + 4;  // next four bytes is for data
                                                                // offset or value.
            // Look up a corresponding tag from tag number
            String tagName = (String) sExifTagMapsForReading[hint].get(tagNumber);

            if (DEBUG) {
                Log.d(TAG, String.format("hint: %d, tagNumber: %d, tagName: %s, dataFormat: %d, " +
                        "numberOfComponents: %d", hint, tagNumber, tagName, dataFormat,
                        numberOfComponents));
            }

            if (tagName == null || dataFormat <= 0 ||
                    dataFormat >= IFD_FORMAT_BYTES_PER_FORMAT.length) {
                // Skip if the parsed tag number is not defined or invalid data format.
                if (tagName == null) {
                    Log.w(TAG, "Skip the tag entry since tag number is not defined: " + tagNumber);
                } else {
                    Log.w(TAG, "Skip the tag entry since data format is invalid: " + dataFormat);
                }
                dataInputStream.seek(nextEntryOffset);
                continue;
            }

            // Read a value from data field or seek to the value offset which is stored in data
            // field if the size of the entry value is bigger than 4.
            int byteCount = numberOfComponents * IFD_FORMAT_BYTES_PER_FORMAT[dataFormat];
            if (byteCount > 4) {
                long offset = dataInputStream.readUnsignedInt();
                if (DEBUG) {
                    Log.d(TAG, "seek to data offset: " + offset);
                }
                if (offset + byteCount <= dataInputStream.mLength) {
                    dataInputStream.seek(offset);
                } else {
                     // Skip if invalid data offset.
                    Log.w(TAG, "Skip the tag entry since data offset is invalid: " + offset);
                    dataInputStream.seek(nextEntryOffset);
                    continue;
                }
            }

            // Recursively parse IFD when a IFD pointer tag appears.
            int innerIfdHint = getIfdHintFromTagNumber(tagNumber);
            if (DEBUG) {
                Log.d(TAG, "innerIfdHint: " + innerIfdHint + " byteCount: " + byteCount);
            }
            if (innerIfdHint >= 0) {
                long offset = -1L;
                // Get offset from data field
                switch (dataFormat) {
                    case IFD_FORMAT_USHORT: {
                        offset = dataInputStream.readUnsignedShort();
                        break;
                    }
                    case IFD_FORMAT_SSHORT: {
                        offset = dataInputStream.readShort();
                        break;
                    }
                    case IFD_FORMAT_ULONG: {
                        offset = dataInputStream.readUnsignedInt();
                        break;
                    }
                    case IFD_FORMAT_SLONG: {
                        offset = dataInputStream.readInt();
                        break;
                    }
                    default: {
                        // Nothing to do
                        break;
                    }
                }
                if (DEBUG) {
                    Log.d(TAG, String.format("Offset: %d, tagName: %s", offset, tagName));
                }
                if (offset > 0L && offset < dataInputStream.mLength) {
                    dataInputStream.seek(offset);
                    readImageFileDirectory(dataInputStream, innerIfdHint);
                } else {
                    Log.w(TAG, "Skip jump into the IFD since its offset is invalid: " + offset);
                }

                dataInputStream.seek(nextEntryOffset);
                continue;
            }

            if (numberOfComponents == 1 || dataFormat == IFD_FORMAT_STRING
                    || dataFormat == IFD_FORMAT_UNDEFINED) {
                String entryValue = readExifEntryValue(
                        dataInputStream, dataFormat, numberOfComponents);
                if (entryValue != null) {
                    mAttributes[hint].put(tagName, entryValue);
                }
            } else {
                StringBuilder entryValueBuilder = new StringBuilder();
                for (int c = 0; c < numberOfComponents; ++c) {
                    if (entryValueBuilder.length() > 0) {
                        entryValueBuilder.append(",");
                    }
                    entryValueBuilder.append(readExifEntryValue(
                            dataInputStream, dataFormat, numberOfComponents));
                }
                mAttributes[hint].put(tagName, entryValueBuilder.toString());
            }

            if (dataInputStream.peek() != nextEntryOffset) {
                dataInputStream.seek(nextEntryOffset);
            }
        }

        if (dataInputStream.peek() + 4 <= dataInputStream.mLength) {
            long nextIfdOffset = dataInputStream.readUnsignedInt();
            if (DEBUG) {
                Log.d(TAG, String.format("nextIfdOffset: %d", nextIfdOffset));
            }
            // The next IFD offset needs to be bigger than 8
            // since the first IFD offset is at least 8.
            if (nextIfdOffset > 8 && nextIfdOffset < dataInputStream.mLength) {
                dataInputStream.seek(nextIfdOffset);
                readImageFileDirectory(dataInputStream, IFD_THUMBNAIL_HINT);
            }
        }
    }

    // Reads a value from where the entry value are stored.
    private String readExifEntryValue(ByteOrderAwarenessDataInputStream dataInputStream,
            int dataFormat, int numberOfComponents) throws IOException {
        // See TIFF 6.0 spec Types. page 15.
        switch (dataFormat) {
            case IFD_FORMAT_BYTE: {
                return String.valueOf(dataInputStream.readByte());
            }
            case IFD_FORMAT_SBYTE: {
                return String.valueOf(dataInputStream.readByte() & 0xff);
            }
            case IFD_FORMAT_USHORT: {
                return String.valueOf(dataInputStream.readUnsignedShort());
            }
            case IFD_FORMAT_SSHORT: {
                return String.valueOf(dataInputStream.readUnsignedInt());
            }
            case IFD_FORMAT_ULONG: {
                return String.valueOf(dataInputStream.readInt());
            }
            case IFD_FORMAT_SLONG: {
                return String.valueOf(dataInputStream.readInt());
            }
            case IFD_FORMAT_URATIONAL:
            case IFD_FORMAT_SRATIONAL: {
                int numerator = dataInputStream.readInt();
                int denominator = dataInputStream.readInt();
                return numerator + "/" + denominator;
            }
            case IFD_FORMAT_SINGLE: {
                return String.valueOf(dataInputStream.readFloat());
            }
            case IFD_FORMAT_DOUBLE: {
                return String.valueOf(dataInputStream.readDouble());
            }
            case IFD_FORMAT_UNDEFINED:  // Usually UNDEFINED format is ASCII.
            case IFD_FORMAT_STRING: {
                byte[] bytes = new byte[numberOfComponents];
                dataInputStream.readFully(bytes);
                int index = 0;
                if (numberOfComponents >= EXIF_ASCII_PREFIX.length) {
                    boolean same = true;
                    for (int i = 0; i < EXIF_ASCII_PREFIX.length; ++i) {
                        if (bytes[i] != EXIF_ASCII_PREFIX[i]) {
                            same = false;
                            break;
                        }
                    }
                    if (same) {
                        index = EXIF_ASCII_PREFIX.length;
                    }
                }

                StringBuilder stringBuilder = new StringBuilder();
                while (index < numberOfComponents) {
                    int ch = bytes[index];
                    if (ch == 0) {
                        break;
                    }
                    if (ch >= 32) {
                        stringBuilder.append((char) ch);
                    }
                    else {
                        stringBuilder.append('?');
                    }
                    ++index;
                }
                return stringBuilder.toString();
            }
            default: {
                // Nothing to do
                return null;
            }
        }
    }

    // Gets the corresponding IFD group index of the given tag number for writing Exif Tags.
    private static int getIfdHintFromTagNumber(int tagNumber) {
        for (int i = 0; i < IFD_POINTER_TAG_HINTS.length; ++i) {
            if (IFD_POINTER_TAGS[i].number == tagNumber) {
                return IFD_POINTER_TAG_HINTS[i];
            }
        }
        return -1;
    }

    // Writes an Exif segment into the given output stream.
    private int writeExifSegment(ExifDataOutputStream dataOutputStream, int exifOffsetFromBeginning)
            throws IOException {
        // The following variables are for calculating each IFD tag group size in bytes.
        int[] ifdOffsets = new int[EXIF_TAGS.length];
        int[] ifdDataSizes = new int[EXIF_TAGS.length];

        // Remove IFD pointer tags (we'll re-add it later.)
        for (ExifTag tag : IFD_POINTER_TAGS) {
            removeAttribute(tag.name);
        }
        // Remove old thumbnail data
        removeAttribute(JPEG_INTERCHANGE_FORMAT_TAG.name);
        removeAttribute(JPEG_INTERCHANGE_FORMAT_LENGTH_TAG.name);

        // Remove null value tags.
        for (int hint = 0; hint < EXIF_TAGS.length; ++hint) {
            for (Object obj : mAttributes[hint].entrySet().toArray()) {
                Map.Entry entry = (Map.Entry) obj;
                if (entry.getValue() == null) {
                    mAttributes[hint].remove(entry.getKey());
                }
            }
        }

        // Add IFD pointer tags. The next offset of primary image TIFF IFD will have thumbnail IFD
        // offset when there is one or more tags in the thumbnail IFD.
        if (!mAttributes[IFD_INTEROPERABILITY_HINT].isEmpty()) {
            mAttributes[IFD_EXIF_HINT].put(IFD_POINTER_TAGS[2].name, "0");
        }
        if (!mAttributes[IFD_EXIF_HINT].isEmpty()) {
            mAttributes[IFD_TIFF_HINT].put(IFD_POINTER_TAGS[0].name, "0");
        }
        if (!mAttributes[IFD_GPS_HINT].isEmpty()) {
            mAttributes[IFD_TIFF_HINT].put(IFD_POINTER_TAGS[1].name, "0");
        }
        if (mHasThumbnail) {
            mAttributes[IFD_TIFF_HINT].put(JPEG_INTERCHANGE_FORMAT_TAG.name, "0");
            mAttributes[IFD_TIFF_HINT].put(JPEG_INTERCHANGE_FORMAT_LENGTH_TAG.name,
                    String.valueOf(mThumbnailLength));
        }

        // Calculate IFD group data area sizes. IFD group data area is assigned to save the entry
        // value which has a bigger size than 4 bytes.
        for (int i = 0; i < 5; ++i) {
            int sum = 0;
            for (Map.Entry entry : (Set<Map.Entry>) mAttributes[i].entrySet()) {
                String entryValue = (String) ((Map.Entry) entry).getValue();
                int dataFormat = getDataFormatOfExifEntryValue(entryValue);
                int size = getSizeOfExifEntryValue(dataFormat, entryValue);
                if (size > 4) {
                    sum += size;
                }
            }
            ifdDataSizes[i] += sum;
        }

        // Calculate IFD offsets.
        int position = 8;
        for (int hint = 0; hint < EXIF_TAGS.length; ++hint) {
            if (!mAttributes[hint].isEmpty()) {
                ifdOffsets[hint] = position;
                position += 2 + mAttributes[hint].size() * 12 + 4 + ifdDataSizes[hint];
            }
        }
        if (mHasThumbnail) {
            int thumbnailOffset = position;
            mAttributes[IFD_TIFF_HINT].put(JPEG_INTERCHANGE_FORMAT_TAG.name,
                    String.valueOf(thumbnailOffset));
            mAttributes[IFD_TIFF_HINT].put(JPEG_INTERCHANGE_FORMAT_LENGTH_TAG.name,
                    String.valueOf(mThumbnailLength));
            mThumbnailOffset = exifOffsetFromBeginning + thumbnailOffset;
            position += mThumbnailLength;
        }

        // Calculate the total size
        int totalSize = position + 8;  // eight bytes is for header part.
        if (DEBUG) {
            Log.d(TAG, "totalSize length: " + totalSize);
            for (int i = 0; i < 5; ++i) {
                Log.d(TAG, String.format("index: %d, offsets: %d, tag count: %d, data sizes: %d",
                        i, ifdOffsets[i], mAttributes[i].size(), ifdDataSizes[i]));
            }
        }

        // Update IFD pointer tags with the calculated offsets.
        if (!mAttributes[IFD_EXIF_HINT].isEmpty()) {
            mAttributes[IFD_TIFF_HINT].put(IFD_POINTER_TAGS[0].name,
                    String.valueOf(ifdOffsets[IFD_EXIF_HINT]));
        }
        if (!mAttributes[IFD_GPS_HINT].isEmpty()) {
            mAttributes[IFD_TIFF_HINT].put(IFD_POINTER_TAGS[1].name,
                    String.valueOf(ifdOffsets[IFD_GPS_HINT]));
        }
        if (!mAttributes[IFD_INTEROPERABILITY_HINT].isEmpty()) {
            mAttributes[IFD_EXIF_HINT].put(IFD_POINTER_TAGS[2].name,
                    String.valueOf(ifdOffsets[IFD_INTEROPERABILITY_HINT]));
        }

        // Write TIFF Headers. See JEITA CP-3451C Table 1. page 10.
        dataOutputStream.writeUnsignedShort(totalSize);
        dataOutputStream.write(IDENTIFIER_EXIF_APP1);
        dataOutputStream.writeShort(BYTE_ALIGN_MM);
        dataOutputStream.writeUnsignedShort(0x2a);
        dataOutputStream.writeUnsignedInt(8);

        // Write IFD groups. See JEITA CP-3451C Figure 7. page 12.
        for (int hint = 0; hint < EXIF_TAGS.length; ++hint) {
            if (!mAttributes[hint].isEmpty()) {
                // See JEITA CP-3451C 4.6.2 IFD structure. page 13.
                // Write entry count
                dataOutputStream.writeUnsignedShort(mAttributes[hint].size());

                // Write entry info
                int dataOffset = ifdOffsets[hint] + 2 + mAttributes[hint].size() * 12 + 4;
                for (Map.Entry entry : (Set<Map.Entry>) mAttributes[hint].entrySet()) {
                    // Convert tag name to tag number.
                    int tagNumber = (int) sExifTagMapsForWriting[hint].get(entry.getKey());
                    String entryValue = (String) entry.getValue();

                    int dataFormat = getDataFormatOfExifEntryValue(entryValue);
                    int numberOfComponents = getNumberOfComponentsInExifEntryValue(dataFormat,
                            entryValue);
                    int byteCount = getSizeOfExifEntryValue(dataFormat, entryValue);

                    dataOutputStream.writeUnsignedShort(tagNumber);
                    dataOutputStream.writeUnsignedShort(dataFormat);
                    dataOutputStream.writeInt(numberOfComponents);
                    if (byteCount > 4) {
                        dataOutputStream.writeUnsignedInt(dataOffset);
                        dataOffset += byteCount;
                    } else {
                        int bytesWritten = writeExifEntryValue(dataOutputStream, entryValue);
                        // Fill zero up to 4 bytes
                        if (bytesWritten < 4) {
                            for (int i = bytesWritten; i < 4; ++i) {
                                dataOutputStream.write(0);
                            }
                        }
                    }
                }

                // Write the next offset. It writes the offset of thumbnail IFD if there is one or
                // more tags in the thumbnail IFD when the current IFD is the primary image TIFF
                // IFD; Otherwise 0.
                if (hint == 0 && !mAttributes[IFD_THUMBNAIL_HINT].isEmpty()) {
                    dataOutputStream.writeUnsignedInt(ifdOffsets[IFD_THUMBNAIL_HINT]);
                } else {
                    dataOutputStream.writeUnsignedInt(0);
                }

                // Write values of data field exceeding 4 bytes after the next offset.
                for (Map.Entry entry : (Set<Map.Entry>) mAttributes[hint].entrySet()) {
                    String entryValue = (String) entry.getValue();

                    int dataFormat = getDataFormatOfExifEntryValue(entryValue);
                    int byteCount = getSizeOfExifEntryValue(dataFormat, entryValue);
                    if (byteCount > 4) {
                        writeExifEntryValue(dataOutputStream, entryValue);
                    }
                }
            }
        }

        // Write thumbnail
        if (mHasThumbnail) {
            dataOutputStream.write(getThumbnail());
        }

        return totalSize;
    }

    // Writes EXIF entry value and its entry value type will be automatically determined.
    private static int writeExifEntryValue(ExifDataOutputStream dataOutputStream, String entryValue)
            throws IOException {
        int bytesWritten = 0;
        int dataFormat = getDataFormatOfExifEntryValue(entryValue);

        if (dataFormat == IFD_FORMAT_STRING) {
            byte[] asciiArray = (entryValue + '\0').getBytes(Charset.forName("US-ASCII"));
            dataOutputStream.write(asciiArray);
            return asciiArray.length;
        }

        // Values can be composed of several components. Each component is separated by char ','.
        String[] components = entryValue.split(",");
        for (String component : components) {
            switch (dataFormat) {
                case IFD_FORMAT_SLONG:
                    dataOutputStream.writeInt(Integer.parseInt(component));
                    bytesWritten += 4;
                    break;
                case IFD_FORMAT_DOUBLE:
                    dataOutputStream.writeDouble(Double.parseDouble(component));
                    bytesWritten += 8;
                    break;
                case IFD_FORMAT_SRATIONAL:
                    String[] rationalNumber = component.split("/");
                    dataOutputStream.writeInt(Integer.parseInt(rationalNumber[0]));
                    dataOutputStream.writeInt(Integer.parseInt(rationalNumber[1]));
                    bytesWritten += 8;
                    break;
                default:
                    throw new IllegalArgumentException();
            }
        }
        return bytesWritten;
    }

    // Determines the data format of EXIF entry value.
    private static int getDataFormatOfExifEntryValue(String entryValue) {
        // See TIFF 6.0 spec Types. page 15.
        // Take the first component if there are more than one component.
        if (entryValue.contains(",")) {
            String[] entryValues = entryValue.split(",");
            int dataFormat = getDataFormatOfExifEntryValue(entryValues[0]);
            if (dataFormat == IFD_FORMAT_STRING) {
                return IFD_FORMAT_STRING;
            }
            for (int i = 1; i < entryValues.length; ++i) {
                if (getDataFormatOfExifEntryValue(entryValues[i]) != dataFormat) {
                    return IFD_FORMAT_STRING;
                }
            }
            return dataFormat;
        }

        if (entryValue.contains("/")) {
            String[] rationalNumber = entryValue.split("/");
            if (rationalNumber.length == 2) {
                try {
                    Integer.parseInt(rationalNumber[0]);
                    Integer.parseInt(rationalNumber[1]);
                    return IFD_FORMAT_SRATIONAL;
                } catch (NumberFormatException e)  {
                    // Ignored
                }
            }
            return IFD_FORMAT_STRING;
        }
        try {
            Integer.parseInt(entryValue);
            return IFD_FORMAT_SLONG;
        } catch (NumberFormatException e) {
            // Ignored
        }
        try {
            Double.parseDouble(entryValue);
            return IFD_FORMAT_DOUBLE;
        } catch (NumberFormatException e) {
            // Ignored
        }
        return IFD_FORMAT_STRING;
    }

    // Determines the size of EXIF entry value.
    private static int getSizeOfExifEntryValue(int dataFormat, String entryValue) {
        // See TIFF 6.0 spec Types page 15.
        if (dataFormat == IFD_FORMAT_STRING) {
            return (entryValue + '\0').getBytes(Charset.forName("US-ASCII")).length;
        }
        int bytesEstimated = 0;
        String[] components = entryValue.split(",");
        for (String component : components) {
            switch (dataFormat) {
                case IFD_FORMAT_SLONG:
                    bytesEstimated += 4;
                    break;
                case IFD_FORMAT_DOUBLE:
                    bytesEstimated += 8;
                    break;
                case IFD_FORMAT_SRATIONAL:
                    bytesEstimated += 8;
                    break;
                default:
                    throw new IllegalArgumentException();
            }
        }
        return bytesEstimated;
    }

    // Determines the number of components of EXIF entry value.
    private static int getNumberOfComponentsInExifEntryValue(int dataFormat, String entryValue) {
        if (dataFormat == IFD_FORMAT_STRING) {
            return (entryValue + '\0').getBytes(Charset.forName("US-ASCII")).length;
        }
        int count = 1;
        for (int i = 0; i < entryValue.length(); ++i) {
            if (entryValue.charAt(i) == ',') {
                ++count;
            }
        }
        return count;
    }

    // An input stream to parse EXIF data area, which can be written in either little or big endian
    // order.
    private static class ByteOrderAwarenessDataInputStream extends ByteArrayInputStream {
        private static final ByteOrder LITTLE_ENDIAN = ByteOrder.LITTLE_ENDIAN;
        private static final ByteOrder BIG_ENDIAN = ByteOrder.BIG_ENDIAN;

        private ByteOrder mByteOrder = ByteOrder.BIG_ENDIAN;
        private final long mLength;
        private long mPosition;

        public ByteOrderAwarenessDataInputStream(byte[] bytes) {
            super(bytes);
            mLength = bytes.length;
            mPosition = 0L;
        }

        public void setByteOrder(ByteOrder byteOrder) {
            mByteOrder = byteOrder;
        }

        public void seek(long byteCount) throws IOException {
            mPosition = 0L;
            reset();
            if (skip(byteCount) != byteCount) {
                throw new IOException("Couldn't seek up to the byteCount");
            }
        }

        public long peek() {
            return mPosition;
        }

        public void readFully(byte[] buffer) throws IOException {
            mPosition += buffer.length;
            if (mPosition > mLength) {
                throw new EOFException();
            }
            if (super.read(buffer, 0, buffer.length) != buffer.length) {
                throw new IOException("Couldn't read up to the length of buffer");
            }
        }

        public byte readByte() throws IOException {
            ++mPosition;
            if (mPosition > mLength) {
                throw new EOFException();
            }
            int ch = super.read();
            if (ch < 0) {
                throw new EOFException();
            }
            return (byte) ch;
        }

        public short readShort() throws IOException {
            mPosition += 2;
            if (mPosition > mLength) {
                throw new EOFException();
            }
            int ch1 = super.read();
            int ch2 = super.read();
            if ((ch1 | ch2) < 0) {
                throw new EOFException();
            }
            if (mByteOrder == LITTLE_ENDIAN) {
                return (short) ((ch2 << 8) + (ch1));
            } else if (mByteOrder == BIG_ENDIAN) {
                return (short) ((ch1 << 8) + (ch2));
            }
            throw new IOException("Invalid byte order: " + mByteOrder);
        }

        public int readInt() throws IOException {
            mPosition += 4;
            if (mPosition > mLength) {
                throw new EOFException();
            }
            int ch1 = super.read();
            int ch2 = super.read();
            int ch3 = super.read();
            int ch4 = super.read();
            if ((ch1 | ch2 | ch3 | ch4) < 0) {
                throw new EOFException();
            }
            if (mByteOrder == LITTLE_ENDIAN) {
                return ((ch4 << 24) + (ch3 << 16) + (ch2 << 8) + ch1);
            } else if (mByteOrder == BIG_ENDIAN) {
                return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + ch4);
            }
            throw new IOException("Invalid byte order: " + mByteOrder);
        }

        @Override
        public long skip(long byteCount) {
            long skipped = super.skip(Math.min(byteCount, mLength - mPosition));
            mPosition += skipped;
            return skipped;
        }

        public int readUnsignedShort() throws IOException {
            mPosition += 2;
            if (mPosition > mLength) {
                throw new EOFException();
            }
            int ch1 = super.read();
            int ch2 = super.read();
            if ((ch1 | ch2) < 0) {
                throw new EOFException();
            }
            if (mByteOrder == LITTLE_ENDIAN) {
                return ((ch2 << 8) + (ch1));
            } else if (mByteOrder == BIG_ENDIAN) {
                return ((ch1 << 8) + (ch2));
            }
            throw new IOException("Invalid byte order: " + mByteOrder);
        }

        public long readUnsignedInt() throws IOException {
            return readInt() & 0xffffffffL;
        }

        public long readLong() throws IOException {
            mPosition += 8;
            if (mPosition > mLength) {
                throw new EOFException();
            }
            int ch1 = super.read();
            int ch2 = super.read();
            int ch3 = super.read();
            int ch4 = super.read();
            int ch5 = super.read();
            int ch6 = super.read();
            int ch7 = super.read();
            int ch8 = super.read();
            if ((ch1 | ch2 | ch3 | ch4 | ch5 | ch6 | ch7 | ch8) < 0) {
                throw new EOFException();
            }
            if (mByteOrder == LITTLE_ENDIAN) {
                return (((long) ch8 << 56) + ((long) ch7 << 48) + ((long) ch6 << 40)
                        + ((long) ch5 << 32) + ((long) ch4 << 24) + ((long) ch3 << 16)
                        + ((long) ch2 << 8) + (long) ch1);
            } else if (mByteOrder == BIG_ENDIAN) {
                return (((long) ch1 << 56) + ((long) ch2 << 48) + ((long) ch3 << 40)
                        + ((long) ch4 << 32) + ((long) ch5 << 24) + ((long) ch6 << 16)
                        + ((long) ch7 << 8) + (long) ch8);
            }
            throw new IOException("Invalid byte order: " + mByteOrder);
        }

        public float readFloat() throws IOException {
            return Float.intBitsToFloat(readInt());
        }

        public double readDouble() throws IOException {
            return Double.longBitsToDouble(readLong());
        }
    }

    // An output stream to write EXIF data area, that will be written in big endian byte order.
    private static class ExifDataOutputStream extends DataOutputStream {
        public ExifDataOutputStream(OutputStream out) {
            super(out);
        }

        public void writeUnsignedShort(int val) throws IOException {
            writeShort((short) val);
        }

        public void writeUnsignedInt(long val) throws IOException {
            writeInt((int) val);
        }
    }

    // JNI methods for RAW formats.
    private static native void nativeInitRaw();
    private static native byte[] nativeGetThumbnailFromAsset(
            long asset, int thumbnailOffset, int thumbnailLength);
    private static native HashMap nativeGetRawAttributesFromAsset(long asset);
    private static native HashMap nativeGetRawAttributesFromFileDescriptor(FileDescriptor fd);
    private static native HashMap nativeGetRawAttributesFromInputStream(InputStream in);
}