ExifInterface.java revision 9af92dadc9ceaa76997753f7199f5ecfeb820327
1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.media;
18
19import android.annotation.NonNull;
20import android.content.res.AssetManager;
21import android.graphics.Bitmap;
22import android.graphics.BitmapFactory;
23import android.system.ErrnoException;
24import android.system.Os;
25import android.system.OsConstants;
26import android.util.Log;
27import android.util.Pair;
28import android.annotation.IntDef;
29
30import java.io.BufferedInputStream;
31import java.io.ByteArrayInputStream;
32import java.io.DataInputStream;
33import java.io.DataInput;
34import java.io.EOFException;
35import java.io.File;
36import java.io.FileDescriptor;
37import java.io.FileInputStream;
38import java.io.FileNotFoundException;
39import java.io.FileOutputStream;
40import java.io.FilterOutputStream;
41import java.io.IOException;
42import java.io.InputStream;
43import java.io.OutputStream;
44import java.nio.ByteBuffer;
45import java.nio.ByteOrder;
46import java.nio.charset.Charset;
47import java.nio.charset.StandardCharsets;
48import java.text.ParsePosition;
49import java.text.SimpleDateFormat;
50import java.util.Arrays;
51import java.util.LinkedList;
52import java.util.Date;
53import java.util.HashMap;
54import java.util.HashSet;
55import java.util.Map;
56import java.util.Set;
57import java.util.TimeZone;
58import java.util.regex.Matcher;
59import java.util.regex.Pattern;
60import java.lang.annotation.Retention;
61import java.lang.annotation.RetentionPolicy;
62
63import libcore.io.IoUtils;
64import libcore.io.Streams;
65
66/**
67 * This is a class for reading and writing Exif tags in a JPEG file or a RAW image file.
68 * <p>
69 * Supported formats are: JPEG, DNG, CR2, NEF, NRW, ARW, RW2, ORF, PEF, SRW and RAF.
70 * <p>
71 * Attribute mutation is supported for JPEG image files.
72 */
73public class ExifInterface {
74    private static final String TAG = "ExifInterface";
75    private static final boolean DEBUG = false;
76
77    // The Exif tag names. See Tiff 6.0 Section 3 and Section 8.
78    /** Type is String. */
79    public static final String TAG_ARTIST = "Artist";
80    /** Type is int. */
81    public static final String TAG_BITS_PER_SAMPLE = "BitsPerSample";
82    /** Type is int. */
83    public static final String TAG_COMPRESSION = "Compression";
84    /** Type is String. */
85    public static final String TAG_COPYRIGHT = "Copyright";
86    /** Type is String. */
87    public static final String TAG_DATETIME = "DateTime";
88    /** Type is String. */
89    public static final String TAG_IMAGE_DESCRIPTION = "ImageDescription";
90    /** Type is int. */
91    public static final String TAG_IMAGE_LENGTH = "ImageLength";
92    /** Type is int. */
93    public static final String TAG_IMAGE_WIDTH = "ImageWidth";
94    /** Type is int. */
95    public static final String TAG_JPEG_INTERCHANGE_FORMAT = "JPEGInterchangeFormat";
96    /** Type is int. */
97    public static final String TAG_JPEG_INTERCHANGE_FORMAT_LENGTH = "JPEGInterchangeFormatLength";
98    /** Type is String. */
99    public static final String TAG_MAKE = "Make";
100    /** Type is String. */
101    public static final String TAG_MODEL = "Model";
102    /** Type is int. */
103    public static final String TAG_ORIENTATION = "Orientation";
104    /** Type is int. */
105    public static final String TAG_PHOTOMETRIC_INTERPRETATION = "PhotometricInterpretation";
106    /** Type is int. */
107    public static final String TAG_PLANAR_CONFIGURATION = "PlanarConfiguration";
108    /** Type is rational. */
109    public static final String TAG_PRIMARY_CHROMATICITIES = "PrimaryChromaticities";
110    /** Type is rational. */
111    public static final String TAG_REFERENCE_BLACK_WHITE = "ReferenceBlackWhite";
112    /** Type is int. */
113    public static final String TAG_RESOLUTION_UNIT = "ResolutionUnit";
114    /** Type is int. */
115    public static final String TAG_ROWS_PER_STRIP = "RowsPerStrip";
116    /** Type is int. */
117    public static final String TAG_SAMPLES_PER_PIXEL = "SamplesPerPixel";
118    /** Type is String. */
119    public static final String TAG_SOFTWARE = "Software";
120    /** Type is int. */
121    public static final String TAG_STRIP_BYTE_COUNTS = "StripByteCounts";
122    /** Type is int. */
123    public static final String TAG_STRIP_OFFSETS = "StripOffsets";
124    /** Type is int. */
125    public static final String TAG_TRANSFER_FUNCTION = "TransferFunction";
126    /** Type is rational. */
127    public static final String TAG_WHITE_POINT = "WhitePoint";
128    /** Type is rational. */
129    public static final String TAG_X_RESOLUTION = "XResolution";
130    /** Type is rational. */
131    public static final String TAG_Y_CB_CR_COEFFICIENTS = "YCbCrCoefficients";
132    /** Type is int. */
133    public static final String TAG_Y_CB_CR_POSITIONING = "YCbCrPositioning";
134    /** Type is int. */
135    public static final String TAG_Y_CB_CR_SUB_SAMPLING = "YCbCrSubSampling";
136    /** Type is rational. */
137    public static final String TAG_Y_RESOLUTION = "YResolution";
138    /** Type is rational. */
139    public static final String TAG_APERTURE_VALUE = "ApertureValue";
140    /** Type is rational. */
141    public static final String TAG_BRIGHTNESS_VALUE = "BrightnessValue";
142    /** Type is String. */
143    public static final String TAG_CFA_PATTERN = "CFAPattern";
144    /** Type is int. */
145    public static final String TAG_COLOR_SPACE = "ColorSpace";
146    /** Type is String. */
147    public static final String TAG_COMPONENTS_CONFIGURATION = "ComponentsConfiguration";
148    /** Type is rational. */
149    public static final String TAG_COMPRESSED_BITS_PER_PIXEL = "CompressedBitsPerPixel";
150    /** Type is int. */
151    public static final String TAG_CONTRAST = "Contrast";
152    /** Type is int. */
153    public static final String TAG_CUSTOM_RENDERED = "CustomRendered";
154    /** Type is String. */
155    public static final String TAG_DATETIME_DIGITIZED = "DateTimeDigitized";
156    /** Type is String. */
157    public static final String TAG_DATETIME_ORIGINAL = "DateTimeOriginal";
158    /** Type is String. */
159    public static final String TAG_DEVICE_SETTING_DESCRIPTION = "DeviceSettingDescription";
160    /** Type is double. */
161    public static final String TAG_DIGITAL_ZOOM_RATIO = "DigitalZoomRatio";
162    /** Type is String. */
163    public static final String TAG_EXIF_VERSION = "ExifVersion";
164    /** Type is double. */
165    public static final String TAG_EXPOSURE_BIAS_VALUE = "ExposureBiasValue";
166    /** Type is rational. */
167    public static final String TAG_EXPOSURE_INDEX = "ExposureIndex";
168    /** Type is int. */
169    public static final String TAG_EXPOSURE_MODE = "ExposureMode";
170    /** Type is int. */
171    public static final String TAG_EXPOSURE_PROGRAM = "ExposureProgram";
172    /** Type is double. */
173    public static final String TAG_EXPOSURE_TIME = "ExposureTime";
174    /** Type is double. */
175    public static final String TAG_F_NUMBER = "FNumber";
176    /**
177     * Type is double.
178     *
179     * @deprecated use {@link #TAG_F_NUMBER} instead
180     */
181    @Deprecated
182    public static final String TAG_APERTURE = "FNumber";
183    /** Type is String. */
184    public static final String TAG_FILE_SOURCE = "FileSource";
185    /** Type is int. */
186    public static final String TAG_FLASH = "Flash";
187    /** Type is rational. */
188    public static final String TAG_FLASH_ENERGY = "FlashEnergy";
189    /** Type is String. */
190    public static final String TAG_FLASHPIX_VERSION = "FlashpixVersion";
191    /** Type is rational. */
192    public static final String TAG_FOCAL_LENGTH = "FocalLength";
193    /** Type is int. */
194    public static final String TAG_FOCAL_LENGTH_IN_35MM_FILM = "FocalLengthIn35mmFilm";
195    /** Type is int. */
196    public static final String TAG_FOCAL_PLANE_RESOLUTION_UNIT = "FocalPlaneResolutionUnit";
197    /** Type is rational. */
198    public static final String TAG_FOCAL_PLANE_X_RESOLUTION = "FocalPlaneXResolution";
199    /** Type is rational. */
200    public static final String TAG_FOCAL_PLANE_Y_RESOLUTION = "FocalPlaneYResolution";
201    /** Type is int. */
202    public static final String TAG_GAIN_CONTROL = "GainControl";
203    /** Type is int. */
204    public static final String TAG_ISO_SPEED_RATINGS = "ISOSpeedRatings";
205    /**
206     * Type is int.
207     *
208     * @deprecated use {@link #TAG_ISO_SPEED_RATINGS} instead
209     */
210    @Deprecated
211    public static final String TAG_ISO = "ISOSpeedRatings";
212    /** Type is String. */
213    public static final String TAG_IMAGE_UNIQUE_ID = "ImageUniqueID";
214    /** Type is int. */
215    public static final String TAG_LIGHT_SOURCE = "LightSource";
216    /** Type is String. */
217    public static final String TAG_MAKER_NOTE = "MakerNote";
218    /** Type is rational. */
219    public static final String TAG_MAX_APERTURE_VALUE = "MaxApertureValue";
220    /** Type is int. */
221    public static final String TAG_METERING_MODE = "MeteringMode";
222    /** Type is int. */
223    public static final String TAG_NEW_SUBFILE_TYPE = "NewSubfileType";
224    /** Type is String. */
225    public static final String TAG_OECF = "OECF";
226    /** Type is int. */
227    public static final String TAG_PIXEL_X_DIMENSION = "PixelXDimension";
228    /** Type is int. */
229    public static final String TAG_PIXEL_Y_DIMENSION = "PixelYDimension";
230    /** Type is String. */
231    public static final String TAG_RELATED_SOUND_FILE = "RelatedSoundFile";
232    /** Type is int. */
233    public static final String TAG_SATURATION = "Saturation";
234    /** Type is int. */
235    public static final String TAG_SCENE_CAPTURE_TYPE = "SceneCaptureType";
236    /** Type is String. */
237    public static final String TAG_SCENE_TYPE = "SceneType";
238    /** Type is int. */
239    public static final String TAG_SENSING_METHOD = "SensingMethod";
240    /** Type is int. */
241    public static final String TAG_SHARPNESS = "Sharpness";
242    /** Type is rational. */
243    public static final String TAG_SHUTTER_SPEED_VALUE = "ShutterSpeedValue";
244    /** Type is String. */
245    public static final String TAG_SPATIAL_FREQUENCY_RESPONSE = "SpatialFrequencyResponse";
246    /** Type is String. */
247    public static final String TAG_SPECTRAL_SENSITIVITY = "SpectralSensitivity";
248    /** Type is int. */
249    public static final String TAG_SUBFILE_TYPE = "SubfileType";
250    /** Type is String. */
251    public static final String TAG_SUBSEC_TIME = "SubSecTime";
252    /**
253     * Type is String.
254     *
255     * @deprecated use {@link #TAG_SUBSEC_TIME_DIGITIZED} instead
256     */
257    public static final String TAG_SUBSEC_TIME_DIG = "SubSecTimeDigitized";
258    /** Type is String. */
259    public static final String TAG_SUBSEC_TIME_DIGITIZED = "SubSecTimeDigitized";
260    /**
261     * Type is String.
262     *
263     * @deprecated use {@link #TAG_SUBSEC_TIME_ORIGINAL} instead
264     */
265    public static final String TAG_SUBSEC_TIME_ORIG = "SubSecTimeOriginal";
266    /** Type is String. */
267    public static final String TAG_SUBSEC_TIME_ORIGINAL = "SubSecTimeOriginal";
268    /** Type is int. */
269    public static final String TAG_SUBJECT_AREA = "SubjectArea";
270    /** Type is double. */
271    public static final String TAG_SUBJECT_DISTANCE = "SubjectDistance";
272    /** Type is int. */
273    public static final String TAG_SUBJECT_DISTANCE_RANGE = "SubjectDistanceRange";
274    /** Type is int. */
275    public static final String TAG_SUBJECT_LOCATION = "SubjectLocation";
276    /** Type is String. */
277    public static final String TAG_USER_COMMENT = "UserComment";
278    /** Type is int. */
279    public static final String TAG_WHITE_BALANCE = "WhiteBalance";
280    /**
281     * The altitude (in meters) based on the reference in TAG_GPS_ALTITUDE_REF.
282     * Type is rational.
283     */
284    public static final String TAG_GPS_ALTITUDE = "GPSAltitude";
285    /**
286     * 0 if the altitude is above sea level. 1 if the altitude is below sea
287     * level. Type is int.
288     */
289    public static final String TAG_GPS_ALTITUDE_REF = "GPSAltitudeRef";
290    /** Type is String. */
291    public static final String TAG_GPS_AREA_INFORMATION = "GPSAreaInformation";
292    /** Type is rational. */
293    public static final String TAG_GPS_DOP = "GPSDOP";
294    /** Type is String. */
295    public static final String TAG_GPS_DATESTAMP = "GPSDateStamp";
296    /** Type is rational. */
297    public static final String TAG_GPS_DEST_BEARING = "GPSDestBearing";
298    /** Type is String. */
299    public static final String TAG_GPS_DEST_BEARING_REF = "GPSDestBearingRef";
300    /** Type is rational. */
301    public static final String TAG_GPS_DEST_DISTANCE = "GPSDestDistance";
302    /** Type is String. */
303    public static final String TAG_GPS_DEST_DISTANCE_REF = "GPSDestDistanceRef";
304    /** Type is rational. */
305    public static final String TAG_GPS_DEST_LATITUDE = "GPSDestLatitude";
306    /** Type is String. */
307    public static final String TAG_GPS_DEST_LATITUDE_REF = "GPSDestLatitudeRef";
308    /** Type is rational. */
309    public static final String TAG_GPS_DEST_LONGITUDE = "GPSDestLongitude";
310    /** Type is String. */
311    public static final String TAG_GPS_DEST_LONGITUDE_REF = "GPSDestLongitudeRef";
312    /** Type is int. */
313    public static final String TAG_GPS_DIFFERENTIAL = "GPSDifferential";
314    /** Type is rational. */
315    public static final String TAG_GPS_IMG_DIRECTION = "GPSImgDirection";
316    /** Type is String. */
317    public static final String TAG_GPS_IMG_DIRECTION_REF = "GPSImgDirectionRef";
318    /** Type is rational. Format is "num1/denom1,num2/denom2,num3/denom3". */
319    public static final String TAG_GPS_LATITUDE = "GPSLatitude";
320    /** Type is String. */
321    public static final String TAG_GPS_LATITUDE_REF = "GPSLatitudeRef";
322    /** Type is rational. Format is "num1/denom1,num2/denom2,num3/denom3". */
323    public static final String TAG_GPS_LONGITUDE = "GPSLongitude";
324    /** Type is String. */
325    public static final String TAG_GPS_LONGITUDE_REF = "GPSLongitudeRef";
326    /** Type is String. */
327    public static final String TAG_GPS_MAP_DATUM = "GPSMapDatum";
328    /** Type is String. */
329    public static final String TAG_GPS_MEASURE_MODE = "GPSMeasureMode";
330    /** Type is String. Name of GPS processing method used for location finding. */
331    public static final String TAG_GPS_PROCESSING_METHOD = "GPSProcessingMethod";
332    /** Type is String. */
333    public static final String TAG_GPS_SATELLITES = "GPSSatellites";
334    /** Type is rational. */
335    public static final String TAG_GPS_SPEED = "GPSSpeed";
336    /** Type is String. */
337    public static final String TAG_GPS_SPEED_REF = "GPSSpeedRef";
338    /** Type is String. */
339    public static final String TAG_GPS_STATUS = "GPSStatus";
340    /** Type is String. Format is "hh:mm:ss". */
341    public static final String TAG_GPS_TIMESTAMP = "GPSTimeStamp";
342    /** Type is rational. */
343    public static final String TAG_GPS_TRACK = "GPSTrack";
344    /** Type is String. */
345    public static final String TAG_GPS_TRACK_REF = "GPSTrackRef";
346    /** Type is String. */
347    public static final String TAG_GPS_VERSION_ID = "GPSVersionID";
348    /** Type is String. */
349    public static final String TAG_INTEROPERABILITY_INDEX = "InteroperabilityIndex";
350    /** Type is int. */
351    public static final String TAG_THUMBNAIL_IMAGE_LENGTH = "ThumbnailImageLength";
352    /** Type is int. */
353    public static final String TAG_THUMBNAIL_IMAGE_WIDTH = "ThumbnailImageWidth";
354    /** Type is int. DNG Specification 1.4.0.0. Section 4 */
355    public static final String TAG_DNG_VERSION = "DNGVersion";
356    /** Type is int. DNG Specification 1.4.0.0. Section 4 */
357    public static final String TAG_DEFAULT_CROP_SIZE = "DefaultCropSize";
358    /** Type is undefined. See Olympus MakerNote tags in http://www.exiv2.org/tags-olympus.html. */
359    public static final String TAG_ORF_THUMBNAIL_IMAGE = "ThumbnailImage";
360    /** Type is int. See Olympus Camera Settings tags in http://www.exiv2.org/tags-olympus.html. */
361    public static final String TAG_ORF_PREVIEW_IMAGE_START = "PreviewImageStart";
362    /** Type is int. See Olympus Camera Settings tags in http://www.exiv2.org/tags-olympus.html. */
363    public static final String TAG_ORF_PREVIEW_IMAGE_LENGTH = "PreviewImageLength";
364    /** Type is int. See Olympus Image Processing tags in http://www.exiv2.org/tags-olympus.html. */
365    public static final String TAG_ORF_ASPECT_FRAME = "AspectFrame";
366    /**
367     * Type is int. See PanasonicRaw tags in
368     * http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/PanasonicRaw.html
369     */
370    public static final String TAG_RW2_SENSOR_BOTTOM_BORDER = "SensorBottomBorder";
371    /**
372     * Type is int. See PanasonicRaw tags in
373     * http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/PanasonicRaw.html
374     */
375    public static final String TAG_RW2_SENSOR_LEFT_BORDER = "SensorLeftBorder";
376    /**
377     * Type is int. See PanasonicRaw tags in
378     * http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/PanasonicRaw.html
379     */
380    public static final String TAG_RW2_SENSOR_RIGHT_BORDER = "SensorRightBorder";
381    /**
382     * Type is int. See PanasonicRaw tags in
383     * http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/PanasonicRaw.html
384     */
385    public static final String TAG_RW2_SENSOR_TOP_BORDER = "SensorTopBorder";
386    /**
387     * Type is int. See PanasonicRaw tags in
388     * http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/PanasonicRaw.html
389     */
390    public static final String TAG_RW2_ISO = "ISO";
391    /**
392     * Type is undefined. See PanasonicRaw tags in
393     * http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/PanasonicRaw.html
394     */
395    public static final String TAG_RW2_JPG_FROM_RAW = "JpgFromRaw";
396
397    /**
398     * Private tags used for pointing the other IFD offsets.
399     * The types of the following tags are int.
400     * See JEITA CP-3451C Section 4.6.3: Exif-specific IFD.
401     * For SubIFD, see Note 1 of Adobe PageMaker® 6.0 TIFF Technical Notes.
402     */
403    private static final String TAG_EXIF_IFD_POINTER = "ExifIFDPointer";
404    private static final String TAG_GPS_INFO_IFD_POINTER = "GPSInfoIFDPointer";
405    private static final String TAG_INTEROPERABILITY_IFD_POINTER = "InteroperabilityIFDPointer";
406    private static final String TAG_SUB_IFD_POINTER = "SubIFDPointer";
407    // Proprietary pointer tags used for ORF files.
408    // See http://www.exiv2.org/tags-olympus.html
409    private static final String TAG_ORF_CAMERA_SETTINGS_IFD_POINTER = "CameraSettingsIFDPointer";
410    private static final String TAG_ORF_IMAGE_PROCESSING_IFD_POINTER = "ImageProcessingIFDPointer";
411
412    // Private tags used for thumbnail information.
413    private static final String TAG_HAS_THUMBNAIL = "HasThumbnail";
414    private static final String TAG_THUMBNAIL_OFFSET = "ThumbnailOffset";
415    private static final String TAG_THUMBNAIL_LENGTH = "ThumbnailLength";
416    private static final String TAG_THUMBNAIL_DATA = "ThumbnailData";
417    private static final int MAX_THUMBNAIL_SIZE = 512;
418
419    // Constants used for the Orientation Exif tag.
420    public static final int ORIENTATION_UNDEFINED = 0;
421    public static final int ORIENTATION_NORMAL = 1;
422    public static final int ORIENTATION_FLIP_HORIZONTAL = 2;  // left right reversed mirror
423    public static final int ORIENTATION_ROTATE_180 = 3;
424    public static final int ORIENTATION_FLIP_VERTICAL = 4;  // upside down mirror
425    // flipped about top-left <--> bottom-right axis
426    public static final int ORIENTATION_TRANSPOSE = 5;
427    public static final int ORIENTATION_ROTATE_90 = 6;  // rotate 90 cw to right it
428    // flipped about top-right <--> bottom-left axis
429    public static final int ORIENTATION_TRANSVERSE = 7;
430    public static final int ORIENTATION_ROTATE_270 = 8;  // rotate 270 to right it
431
432    // Constants used for white balance
433    public static final int WHITEBALANCE_AUTO = 0;
434    public static final int WHITEBALANCE_MANUAL = 1;
435
436    // Maximum size for checking file type signature (see image_type_recognition_lite.cc)
437    private static final int SIGNATURE_CHECK_SIZE = 5000;
438
439    private static final byte[] JPEG_SIGNATURE = new byte[] {(byte) 0xff, (byte) 0xd8, (byte) 0xff};
440    private static final String RAF_SIGNATURE = "FUJIFILMCCD-RAW";
441    private static final int RAF_OFFSET_TO_JPEG_IMAGE_OFFSET = 84;
442    private static final int RAF_INFO_SIZE = 160;
443    private static final int RAF_JPEG_LENGTH_VALUE_SIZE = 4;
444
445    private static final byte[] HEIF_TYPE_FTYP = new byte[] {'f', 't', 'y', 'p'};
446    private static final byte[] HEIF_BRAND_MIF1 = new byte[] {'m', 'i', 'f', '1'};
447    private static final byte[] HEIF_BRAND_HEIC = new byte[] {'h', 'e', 'i', 'c'};
448
449    // See http://fileformats.archiveteam.org/wiki/Olympus_ORF
450    private static final short ORF_SIGNATURE_1 = 0x4f52;
451    private static final short ORF_SIGNATURE_2 = 0x5352;
452    // There are two formats for Olympus Makernote Headers. Each has different identifiers and
453    // offsets to the actual data.
454    // See http://www.exiv2.org/makernote.html#R1
455    private static final byte[] ORF_MAKER_NOTE_HEADER_1 = new byte[] {(byte) 0x4f, (byte) 0x4c,
456            (byte) 0x59, (byte) 0x4d, (byte) 0x50, (byte) 0x00}; // "OLYMP\0"
457    private static final byte[] ORF_MAKER_NOTE_HEADER_2 = new byte[] {(byte) 0x4f, (byte) 0x4c,
458            (byte) 0x59, (byte) 0x4d, (byte) 0x50, (byte) 0x55, (byte) 0x53, (byte) 0x00,
459            (byte) 0x49, (byte) 0x49}; // "OLYMPUS\0II"
460    private static final int ORF_MAKER_NOTE_HEADER_1_SIZE = 8;
461    private static final int ORF_MAKER_NOTE_HEADER_2_SIZE = 12;
462
463    // See http://fileformats.archiveteam.org/wiki/RW2
464    private static final short RW2_SIGNATURE = 0x0055;
465
466    // See http://fileformats.archiveteam.org/wiki/Pentax_PEF
467    private static final String PEF_SIGNATURE = "PENTAX";
468    // See http://www.exiv2.org/makernote.html#R11
469    private static final int PEF_MAKER_NOTE_SKIP_SIZE = 6;
470
471    private static SimpleDateFormat sFormatter;
472
473    // See Exchangeable image file format for digital still cameras: Exif version 2.2.
474    // The following values are for parsing EXIF data area. There are tag groups in EXIF data area.
475    // They are called "Image File Directory". They have multiple data formats to cover various
476    // image metadata from GPS longitude to camera model name.
477
478    // Types of Exif byte alignments (see JEITA CP-3451C Section 4.5.2)
479    private static final short BYTE_ALIGN_II = 0x4949;  // II: Intel order
480    private static final short BYTE_ALIGN_MM = 0x4d4d;  // MM: Motorola order
481
482    // TIFF Header Fixed Constant (see JEITA CP-3451C Section 4.5.2)
483    private static final byte START_CODE = 0x2a; // 42
484    private static final int IFD_OFFSET = 8;
485
486    // Formats for the value in IFD entry (See TIFF 6.0 Section 2, "Image File Directory".)
487    private static final int IFD_FORMAT_BYTE = 1;
488    private static final int IFD_FORMAT_STRING = 2;
489    private static final int IFD_FORMAT_USHORT = 3;
490    private static final int IFD_FORMAT_ULONG = 4;
491    private static final int IFD_FORMAT_URATIONAL = 5;
492    private static final int IFD_FORMAT_SBYTE = 6;
493    private static final int IFD_FORMAT_UNDEFINED = 7;
494    private static final int IFD_FORMAT_SSHORT = 8;
495    private static final int IFD_FORMAT_SLONG = 9;
496    private static final int IFD_FORMAT_SRATIONAL = 10;
497    private static final int IFD_FORMAT_SINGLE = 11;
498    private static final int IFD_FORMAT_DOUBLE = 12;
499    // Format indicating a new IFD entry (See Adobe PageMaker® 6.0 TIFF Technical Notes, "New Tag")
500    private static final int IFD_FORMAT_IFD = 13;
501    // Names for the data formats for debugging purpose.
502    private static final String[] IFD_FORMAT_NAMES = new String[] {
503            "", "BYTE", "STRING", "USHORT", "ULONG", "URATIONAL", "SBYTE", "UNDEFINED", "SSHORT",
504            "SLONG", "SRATIONAL", "SINGLE", "DOUBLE"
505    };
506    // Sizes of the components of each IFD value format
507    private static final int[] IFD_FORMAT_BYTES_PER_FORMAT = new int[] {
508            0, 1, 1, 2, 4, 8, 1, 1, 2, 4, 8, 4, 8, 1
509    };
510    private static final byte[] EXIF_ASCII_PREFIX = new byte[] {
511            0x41, 0x53, 0x43, 0x49, 0x49, 0x0, 0x0, 0x0
512    };
513
514    /**
515     * Constants used for Compression tag.
516     * For Value 1, 2, 32773, see TIFF 6.0 Spec Section 3: Bilevel Images, Compression
517     * For Value 6, see TIFF 6.0 Spec Section 22: JPEG Compression, Extensions to Existing Fields
518     * For Value 7, 8, 34892, see DNG Specification 1.4.0.0. Section 3, Compression
519     */
520    private static final int DATA_UNCOMPRESSED = 1;
521    private static final int DATA_HUFFMAN_COMPRESSED = 2;
522    private static final int DATA_JPEG = 6;
523    private static final int DATA_JPEG_COMPRESSED = 7;
524    private static final int DATA_DEFLATE_ZIP = 8;
525    private static final int DATA_PACK_BITS_COMPRESSED = 32773;
526    private static final int DATA_LOSSY_JPEG = 34892;
527
528    /**
529     * Constants used for BitsPerSample tag.
530     * For RGB, see TIFF 6.0 Spec Section 6, Differences from Palette Color Images
531     * For Greyscale, see TIFF 6.0 Spec Section 4, Differences from Bilevel Images
532     */
533    private static final int[] BITS_PER_SAMPLE_RGB = new int[] { 8, 8, 8 };
534    private static final int[] BITS_PER_SAMPLE_GREYSCALE_1 = new int[] { 4 };
535    private static final int[] BITS_PER_SAMPLE_GREYSCALE_2 = new int[] { 8 };
536
537    /**
538     * Constants used for PhotometricInterpretation tag.
539     * For White/Black, see Section 3, Color.
540     * See TIFF 6.0 Spec Section 22, Minimum Requirements for TIFF with JPEG Compression.
541     */
542    private static final int PHOTOMETRIC_INTERPRETATION_WHITE_IS_ZERO = 0;
543    private static final int PHOTOMETRIC_INTERPRETATION_BLACK_IS_ZERO = 1;
544    private static final int PHOTOMETRIC_INTERPRETATION_RGB = 2;
545    private static final int PHOTOMETRIC_INTERPRETATION_YCBCR = 6;
546
547    /**
548     * Constants used for NewSubfileType tag.
549     * See TIFF 6.0 Spec Section 8
550     * */
551    private static final int ORIGINAL_RESOLUTION_IMAGE = 0;
552    private static final int REDUCED_RESOLUTION_IMAGE = 1;
553
554    // A class for indicating EXIF rational type.
555    private static class Rational {
556        public final long numerator;
557        public final long denominator;
558
559        private Rational(long numerator, long denominator) {
560            // Handle erroneous case
561            if (denominator == 0) {
562                this.numerator = 0;
563                this.denominator = 1;
564                return;
565            }
566            this.numerator = numerator;
567            this.denominator = denominator;
568        }
569
570        @Override
571        public String toString() {
572            return numerator + "/" + denominator;
573        }
574
575        public double calculate() {
576            return (double) numerator / denominator;
577        }
578    }
579
580    // A class for indicating EXIF attribute.
581    private static class ExifAttribute {
582        public final int format;
583        public final int numberOfComponents;
584        public final byte[] bytes;
585
586        private ExifAttribute(int format, int numberOfComponents, byte[] bytes) {
587            this.format = format;
588            this.numberOfComponents = numberOfComponents;
589            this.bytes = bytes;
590        }
591
592        public static ExifAttribute createUShort(int[] values, ByteOrder byteOrder) {
593            final ByteBuffer buffer = ByteBuffer.wrap(
594                    new byte[IFD_FORMAT_BYTES_PER_FORMAT[IFD_FORMAT_USHORT] * values.length]);
595            buffer.order(byteOrder);
596            for (int value : values) {
597                buffer.putShort((short) value);
598            }
599            return new ExifAttribute(IFD_FORMAT_USHORT, values.length, buffer.array());
600        }
601
602        public static ExifAttribute createUShort(int value, ByteOrder byteOrder) {
603            return createUShort(new int[] {value}, byteOrder);
604        }
605
606        public static ExifAttribute createULong(long[] values, ByteOrder byteOrder) {
607            final ByteBuffer buffer = ByteBuffer.wrap(
608                    new byte[IFD_FORMAT_BYTES_PER_FORMAT[IFD_FORMAT_ULONG] * values.length]);
609            buffer.order(byteOrder);
610            for (long value : values) {
611                buffer.putInt((int) value);
612            }
613            return new ExifAttribute(IFD_FORMAT_ULONG, values.length, buffer.array());
614        }
615
616        public static ExifAttribute createULong(long value, ByteOrder byteOrder) {
617            return createULong(new long[] {value}, byteOrder);
618        }
619
620        public static ExifAttribute createSLong(int[] values, ByteOrder byteOrder) {
621            final ByteBuffer buffer = ByteBuffer.wrap(
622                    new byte[IFD_FORMAT_BYTES_PER_FORMAT[IFD_FORMAT_SLONG] * values.length]);
623            buffer.order(byteOrder);
624            for (int value : values) {
625                buffer.putInt(value);
626            }
627            return new ExifAttribute(IFD_FORMAT_SLONG, values.length, buffer.array());
628        }
629
630        public static ExifAttribute createSLong(int value, ByteOrder byteOrder) {
631            return createSLong(new int[] {value}, byteOrder);
632        }
633
634        public static ExifAttribute createByte(String value) {
635            // Exception for GPSAltitudeRef tag
636            if (value.length() == 1 && value.charAt(0) >= '0' && value.charAt(0) <= '1') {
637                final byte[] bytes = new byte[] { (byte) (value.charAt(0) - '0') };
638                return new ExifAttribute(IFD_FORMAT_BYTE, bytes.length, bytes);
639            }
640            final byte[] ascii = value.getBytes(ASCII);
641            return new ExifAttribute(IFD_FORMAT_BYTE, ascii.length, ascii);
642        }
643
644        public static ExifAttribute createString(String value) {
645            final byte[] ascii = (value + '\0').getBytes(ASCII);
646            return new ExifAttribute(IFD_FORMAT_STRING, ascii.length, ascii);
647        }
648
649        public static ExifAttribute createURational(Rational[] values, ByteOrder byteOrder) {
650            final ByteBuffer buffer = ByteBuffer.wrap(
651                    new byte[IFD_FORMAT_BYTES_PER_FORMAT[IFD_FORMAT_URATIONAL] * values.length]);
652            buffer.order(byteOrder);
653            for (Rational value : values) {
654                buffer.putInt((int) value.numerator);
655                buffer.putInt((int) value.denominator);
656            }
657            return new ExifAttribute(IFD_FORMAT_URATIONAL, values.length, buffer.array());
658        }
659
660        public static ExifAttribute createURational(Rational value, ByteOrder byteOrder) {
661            return createURational(new Rational[] {value}, byteOrder);
662        }
663
664        public static ExifAttribute createSRational(Rational[] values, ByteOrder byteOrder) {
665            final ByteBuffer buffer = ByteBuffer.wrap(
666                    new byte[IFD_FORMAT_BYTES_PER_FORMAT[IFD_FORMAT_SRATIONAL] * values.length]);
667            buffer.order(byteOrder);
668            for (Rational value : values) {
669                buffer.putInt((int) value.numerator);
670                buffer.putInt((int) value.denominator);
671            }
672            return new ExifAttribute(IFD_FORMAT_SRATIONAL, values.length, buffer.array());
673        }
674
675        public static ExifAttribute createSRational(Rational value, ByteOrder byteOrder) {
676            return createSRational(new Rational[] {value}, byteOrder);
677        }
678
679        public static ExifAttribute createDouble(double[] values, ByteOrder byteOrder) {
680            final ByteBuffer buffer = ByteBuffer.wrap(
681                    new byte[IFD_FORMAT_BYTES_PER_FORMAT[IFD_FORMAT_DOUBLE] * values.length]);
682            buffer.order(byteOrder);
683            for (double value : values) {
684                buffer.putDouble(value);
685            }
686            return new ExifAttribute(IFD_FORMAT_DOUBLE, values.length, buffer.array());
687        }
688
689        public static ExifAttribute createDouble(double value, ByteOrder byteOrder) {
690            return createDouble(new double[] {value}, byteOrder);
691        }
692
693        @Override
694        public String toString() {
695            return "(" + IFD_FORMAT_NAMES[format] + ", data length:" + bytes.length + ")";
696        }
697
698        private Object getValue(ByteOrder byteOrder) {
699            try {
700                ByteOrderedDataInputStream inputStream =
701                        new ByteOrderedDataInputStream(bytes);
702                inputStream.setByteOrder(byteOrder);
703                switch (format) {
704                    case IFD_FORMAT_BYTE:
705                    case IFD_FORMAT_SBYTE: {
706                        // Exception for GPSAltitudeRef tag
707                        if (bytes.length == 1 && bytes[0] >= 0 && bytes[0] <= 1) {
708                            return new String(new char[] { (char) (bytes[0] + '0') });
709                        }
710                        return new String(bytes, ASCII);
711                    }
712                    case IFD_FORMAT_UNDEFINED:
713                    case IFD_FORMAT_STRING: {
714                        int index = 0;
715                        if (numberOfComponents >= EXIF_ASCII_PREFIX.length) {
716                            boolean same = true;
717                            for (int i = 0; i < EXIF_ASCII_PREFIX.length; ++i) {
718                                if (bytes[i] != EXIF_ASCII_PREFIX[i]) {
719                                    same = false;
720                                    break;
721                                }
722                            }
723                            if (same) {
724                                index = EXIF_ASCII_PREFIX.length;
725                            }
726                        }
727
728                        StringBuilder stringBuilder = new StringBuilder();
729                        while (index < numberOfComponents) {
730                            int ch = bytes[index];
731                            if (ch == 0) {
732                                break;
733                            }
734                            if (ch >= 32) {
735                                stringBuilder.append((char) ch);
736                            } else {
737                                stringBuilder.append('?');
738                            }
739                            ++index;
740                        }
741                        return stringBuilder.toString();
742                    }
743                    case IFD_FORMAT_USHORT: {
744                        final int[] values = new int[numberOfComponents];
745                        for (int i = 0; i < numberOfComponents; ++i) {
746                            values[i] = inputStream.readUnsignedShort();
747                        }
748                        return values;
749                    }
750                    case IFD_FORMAT_ULONG: {
751                        final long[] values = new long[numberOfComponents];
752                        for (int i = 0; i < numberOfComponents; ++i) {
753                            values[i] = inputStream.readUnsignedInt();
754                        }
755                        return values;
756                    }
757                    case IFD_FORMAT_URATIONAL: {
758                        final Rational[] values = new Rational[numberOfComponents];
759                        for (int i = 0; i < numberOfComponents; ++i) {
760                            final long numerator = inputStream.readUnsignedInt();
761                            final long denominator = inputStream.readUnsignedInt();
762                            values[i] = new Rational(numerator, denominator);
763                        }
764                        return values;
765                    }
766                    case IFD_FORMAT_SSHORT: {
767                        final int[] values = new int[numberOfComponents];
768                        for (int i = 0; i < numberOfComponents; ++i) {
769                            values[i] = inputStream.readShort();
770                        }
771                        return values;
772                    }
773                    case IFD_FORMAT_SLONG: {
774                        final int[] values = new int[numberOfComponents];
775                        for (int i = 0; i < numberOfComponents; ++i) {
776                            values[i] = inputStream.readInt();
777                        }
778                        return values;
779                    }
780                    case IFD_FORMAT_SRATIONAL: {
781                        final Rational[] values = new Rational[numberOfComponents];
782                        for (int i = 0; i < numberOfComponents; ++i) {
783                            final long numerator = inputStream.readInt();
784                            final long denominator = inputStream.readInt();
785                            values[i] = new Rational(numerator, denominator);
786                        }
787                        return values;
788                    }
789                    case IFD_FORMAT_SINGLE: {
790                        final double[] values = new double[numberOfComponents];
791                        for (int i = 0; i < numberOfComponents; ++i) {
792                            values[i] = inputStream.readFloat();
793                        }
794                        return values;
795                    }
796                    case IFD_FORMAT_DOUBLE: {
797                        final double[] values = new double[numberOfComponents];
798                        for (int i = 0; i < numberOfComponents; ++i) {
799                            values[i] = inputStream.readDouble();
800                        }
801                        return values;
802                    }
803                    default:
804                        return null;
805                }
806            } catch (IOException e) {
807                Log.w(TAG, "IOException occurred during reading a value", e);
808                return null;
809            }
810        }
811
812        public double getDoubleValue(ByteOrder byteOrder) {
813            Object value = getValue(byteOrder);
814            if (value == null) {
815                throw new NumberFormatException("NULL can't be converted to a double value");
816            }
817            if (value instanceof String) {
818                return Double.parseDouble((String) value);
819            }
820            if (value instanceof long[]) {
821                long[] array = (long[]) value;
822                if (array.length == 1) {
823                    return array[0];
824                }
825                throw new NumberFormatException("There are more than one component");
826            }
827            if (value instanceof int[]) {
828                int[] array = (int[]) value;
829                if (array.length == 1) {
830                    return array[0];
831                }
832                throw new NumberFormatException("There are more than one component");
833            }
834            if (value instanceof double[]) {
835                double[] array = (double[]) value;
836                if (array.length == 1) {
837                    return array[0];
838                }
839                throw new NumberFormatException("There are more than one component");
840            }
841            if (value instanceof Rational[]) {
842                Rational[] array = (Rational[]) value;
843                if (array.length == 1) {
844                    return array[0].calculate();
845                }
846                throw new NumberFormatException("There are more than one component");
847            }
848            throw new NumberFormatException("Couldn't find a double value");
849        }
850
851        public int getIntValue(ByteOrder byteOrder) {
852            Object value = getValue(byteOrder);
853            if (value == null) {
854                throw new NumberFormatException("NULL can't be converted to a integer value");
855            }
856            if (value instanceof String) {
857                return Integer.parseInt((String) value);
858            }
859            if (value instanceof long[]) {
860                long[] array = (long[]) value;
861                if (array.length == 1) {
862                    return (int) array[0];
863                }
864                throw new NumberFormatException("There are more than one component");
865            }
866            if (value instanceof int[]) {
867                int[] array = (int[]) value;
868                if (array.length == 1) {
869                    return array[0];
870                }
871                throw new NumberFormatException("There are more than one component");
872            }
873            throw new NumberFormatException("Couldn't find a integer value");
874        }
875
876        public String getStringValue(ByteOrder byteOrder) {
877            Object value = getValue(byteOrder);
878            if (value == null) {
879                return null;
880            }
881            if (value instanceof String) {
882                return (String) value;
883            }
884
885            final StringBuilder stringBuilder = new StringBuilder();
886            if (value instanceof long[]) {
887                long[] array = (long[]) value;
888                for (int i = 0; i < array.length; ++i) {
889                    stringBuilder.append(array[i]);
890                    if (i + 1 != array.length) {
891                        stringBuilder.append(",");
892                    }
893                }
894                return stringBuilder.toString();
895            }
896            if (value instanceof int[]) {
897                int[] array = (int[]) value;
898                for (int i = 0; i < array.length; ++i) {
899                    stringBuilder.append(array[i]);
900                    if (i + 1 != array.length) {
901                        stringBuilder.append(",");
902                    }
903                }
904                return stringBuilder.toString();
905            }
906            if (value instanceof double[]) {
907                double[] array = (double[]) value;
908                for (int i = 0; i < array.length; ++i) {
909                    stringBuilder.append(array[i]);
910                    if (i + 1 != array.length) {
911                        stringBuilder.append(",");
912                    }
913                }
914                return stringBuilder.toString();
915            }
916            if (value instanceof Rational[]) {
917                Rational[] array = (Rational[]) value;
918                for (int i = 0; i < array.length; ++i) {
919                    stringBuilder.append(array[i].numerator);
920                    stringBuilder.append('/');
921                    stringBuilder.append(array[i].denominator);
922                    if (i + 1 != array.length) {
923                        stringBuilder.append(",");
924                    }
925                }
926                return stringBuilder.toString();
927            }
928            return null;
929        }
930
931        public int size() {
932            return IFD_FORMAT_BYTES_PER_FORMAT[format] * numberOfComponents;
933        }
934    }
935
936    // A class for indicating EXIF tag.
937    private static class ExifTag {
938        public final int number;
939        public final String name;
940        public final int primaryFormat;
941        public final int secondaryFormat;
942
943        private ExifTag(String name, int number, int format) {
944            this.name = name;
945            this.number = number;
946            this.primaryFormat = format;
947            this.secondaryFormat = -1;
948        }
949
950        private ExifTag(String name, int number, int primaryFormat, int secondaryFormat) {
951            this.name = name;
952            this.number = number;
953            this.primaryFormat = primaryFormat;
954            this.secondaryFormat = secondaryFormat;
955        }
956    }
957
958    // Primary image IFD TIFF tags (See JEITA CP-3451C Section 4.6.8 Tag Support Levels)
959    private static final ExifTag[] IFD_TIFF_TAGS = new ExifTag[] {
960            // For below two, see TIFF 6.0 Spec Section 3: Bilevel Images.
961            new ExifTag(TAG_NEW_SUBFILE_TYPE, 254, IFD_FORMAT_ULONG),
962            new ExifTag(TAG_SUBFILE_TYPE, 255, IFD_FORMAT_ULONG),
963            new ExifTag(TAG_IMAGE_WIDTH, 256, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
964            new ExifTag(TAG_IMAGE_LENGTH, 257, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
965            new ExifTag(TAG_BITS_PER_SAMPLE, 258, IFD_FORMAT_USHORT),
966            new ExifTag(TAG_COMPRESSION, 259, IFD_FORMAT_USHORT),
967            new ExifTag(TAG_PHOTOMETRIC_INTERPRETATION, 262, IFD_FORMAT_USHORT),
968            new ExifTag(TAG_IMAGE_DESCRIPTION, 270, IFD_FORMAT_STRING),
969            new ExifTag(TAG_MAKE, 271, IFD_FORMAT_STRING),
970            new ExifTag(TAG_MODEL, 272, IFD_FORMAT_STRING),
971            new ExifTag(TAG_STRIP_OFFSETS, 273, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
972            new ExifTag(TAG_ORIENTATION, 274, IFD_FORMAT_USHORT),
973            new ExifTag(TAG_SAMPLES_PER_PIXEL, 277, IFD_FORMAT_USHORT),
974            new ExifTag(TAG_ROWS_PER_STRIP, 278, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
975            new ExifTag(TAG_STRIP_BYTE_COUNTS, 279, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
976            new ExifTag(TAG_X_RESOLUTION, 282, IFD_FORMAT_URATIONAL),
977            new ExifTag(TAG_Y_RESOLUTION, 283, IFD_FORMAT_URATIONAL),
978            new ExifTag(TAG_PLANAR_CONFIGURATION, 284, IFD_FORMAT_USHORT),
979            new ExifTag(TAG_RESOLUTION_UNIT, 296, IFD_FORMAT_USHORT),
980            new ExifTag(TAG_TRANSFER_FUNCTION, 301, IFD_FORMAT_USHORT),
981            new ExifTag(TAG_SOFTWARE, 305, IFD_FORMAT_STRING),
982            new ExifTag(TAG_DATETIME, 306, IFD_FORMAT_STRING),
983            new ExifTag(TAG_ARTIST, 315, IFD_FORMAT_STRING),
984            new ExifTag(TAG_WHITE_POINT, 318, IFD_FORMAT_URATIONAL),
985            new ExifTag(TAG_PRIMARY_CHROMATICITIES, 319, IFD_FORMAT_URATIONAL),
986            // See Adobe PageMaker® 6.0 TIFF Technical Notes, Note 1.
987            new ExifTag(TAG_SUB_IFD_POINTER, 330, IFD_FORMAT_ULONG),
988            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT, 513, IFD_FORMAT_ULONG),
989            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH, 514, IFD_FORMAT_ULONG),
990            new ExifTag(TAG_Y_CB_CR_COEFFICIENTS, 529, IFD_FORMAT_URATIONAL),
991            new ExifTag(TAG_Y_CB_CR_SUB_SAMPLING, 530, IFD_FORMAT_USHORT),
992            new ExifTag(TAG_Y_CB_CR_POSITIONING, 531, IFD_FORMAT_USHORT),
993            new ExifTag(TAG_REFERENCE_BLACK_WHITE, 532, IFD_FORMAT_URATIONAL),
994            new ExifTag(TAG_COPYRIGHT, 33432, IFD_FORMAT_STRING),
995            new ExifTag(TAG_EXIF_IFD_POINTER, 34665, IFD_FORMAT_ULONG),
996            new ExifTag(TAG_GPS_INFO_IFD_POINTER, 34853, IFD_FORMAT_ULONG),
997            // RW2 file tags
998            // See http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/PanasonicRaw.html)
999            new ExifTag(TAG_RW2_SENSOR_TOP_BORDER, 4, IFD_FORMAT_ULONG),
1000            new ExifTag(TAG_RW2_SENSOR_LEFT_BORDER, 5, IFD_FORMAT_ULONG),
1001            new ExifTag(TAG_RW2_SENSOR_BOTTOM_BORDER, 6, IFD_FORMAT_ULONG),
1002            new ExifTag(TAG_RW2_SENSOR_RIGHT_BORDER, 7, IFD_FORMAT_ULONG),
1003            new ExifTag(TAG_RW2_ISO, 23, IFD_FORMAT_USHORT),
1004            new ExifTag(TAG_RW2_JPG_FROM_RAW, 46, IFD_FORMAT_UNDEFINED)
1005    };
1006
1007    // Primary image IFD Exif Private tags (See JEITA CP-3451C Section 4.6.8 Tag Support Levels)
1008    private static final ExifTag[] IFD_EXIF_TAGS = new ExifTag[] {
1009            new ExifTag(TAG_EXPOSURE_TIME, 33434, IFD_FORMAT_URATIONAL),
1010            new ExifTag(TAG_F_NUMBER, 33437, IFD_FORMAT_URATIONAL),
1011            new ExifTag(TAG_EXPOSURE_PROGRAM, 34850, IFD_FORMAT_USHORT),
1012            new ExifTag(TAG_SPECTRAL_SENSITIVITY, 34852, IFD_FORMAT_STRING),
1013            new ExifTag(TAG_ISO_SPEED_RATINGS, 34855, IFD_FORMAT_USHORT),
1014            new ExifTag(TAG_OECF, 34856, IFD_FORMAT_UNDEFINED),
1015            new ExifTag(TAG_EXIF_VERSION, 36864, IFD_FORMAT_STRING),
1016            new ExifTag(TAG_DATETIME_ORIGINAL, 36867, IFD_FORMAT_STRING),
1017            new ExifTag(TAG_DATETIME_DIGITIZED, 36868, IFD_FORMAT_STRING),
1018            new ExifTag(TAG_COMPONENTS_CONFIGURATION, 37121, IFD_FORMAT_UNDEFINED),
1019            new ExifTag(TAG_COMPRESSED_BITS_PER_PIXEL, 37122, IFD_FORMAT_URATIONAL),
1020            new ExifTag(TAG_SHUTTER_SPEED_VALUE, 37377, IFD_FORMAT_SRATIONAL),
1021            new ExifTag(TAG_APERTURE_VALUE, 37378, IFD_FORMAT_URATIONAL),
1022            new ExifTag(TAG_BRIGHTNESS_VALUE, 37379, IFD_FORMAT_SRATIONAL),
1023            new ExifTag(TAG_EXPOSURE_BIAS_VALUE, 37380, IFD_FORMAT_SRATIONAL),
1024            new ExifTag(TAG_MAX_APERTURE_VALUE, 37381, IFD_FORMAT_URATIONAL),
1025            new ExifTag(TAG_SUBJECT_DISTANCE, 37382, IFD_FORMAT_URATIONAL),
1026            new ExifTag(TAG_METERING_MODE, 37383, IFD_FORMAT_USHORT),
1027            new ExifTag(TAG_LIGHT_SOURCE, 37384, IFD_FORMAT_USHORT),
1028            new ExifTag(TAG_FLASH, 37385, IFD_FORMAT_USHORT),
1029            new ExifTag(TAG_FOCAL_LENGTH, 37386, IFD_FORMAT_URATIONAL),
1030            new ExifTag(TAG_SUBJECT_AREA, 37396, IFD_FORMAT_USHORT),
1031            new ExifTag(TAG_MAKER_NOTE, 37500, IFD_FORMAT_UNDEFINED),
1032            new ExifTag(TAG_USER_COMMENT, 37510, IFD_FORMAT_UNDEFINED),
1033            new ExifTag(TAG_SUBSEC_TIME, 37520, IFD_FORMAT_STRING),
1034            new ExifTag(TAG_SUBSEC_TIME_ORIG, 37521, IFD_FORMAT_STRING),
1035            new ExifTag(TAG_SUBSEC_TIME_DIG, 37522, IFD_FORMAT_STRING),
1036            new ExifTag(TAG_FLASHPIX_VERSION, 40960, IFD_FORMAT_UNDEFINED),
1037            new ExifTag(TAG_COLOR_SPACE, 40961, IFD_FORMAT_USHORT),
1038            new ExifTag(TAG_PIXEL_X_DIMENSION, 40962, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
1039            new ExifTag(TAG_PIXEL_Y_DIMENSION, 40963, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
1040            new ExifTag(TAG_RELATED_SOUND_FILE, 40964, IFD_FORMAT_STRING),
1041            new ExifTag(TAG_INTEROPERABILITY_IFD_POINTER, 40965, IFD_FORMAT_ULONG),
1042            new ExifTag(TAG_FLASH_ENERGY, 41483, IFD_FORMAT_URATIONAL),
1043            new ExifTag(TAG_SPATIAL_FREQUENCY_RESPONSE, 41484, IFD_FORMAT_UNDEFINED),
1044            new ExifTag(TAG_FOCAL_PLANE_X_RESOLUTION, 41486, IFD_FORMAT_URATIONAL),
1045            new ExifTag(TAG_FOCAL_PLANE_Y_RESOLUTION, 41487, IFD_FORMAT_URATIONAL),
1046            new ExifTag(TAG_FOCAL_PLANE_RESOLUTION_UNIT, 41488, IFD_FORMAT_USHORT),
1047            new ExifTag(TAG_SUBJECT_LOCATION, 41492, IFD_FORMAT_USHORT),
1048            new ExifTag(TAG_EXPOSURE_INDEX, 41493, IFD_FORMAT_URATIONAL),
1049            new ExifTag(TAG_SENSING_METHOD, 41495, IFD_FORMAT_USHORT),
1050            new ExifTag(TAG_FILE_SOURCE, 41728, IFD_FORMAT_UNDEFINED),
1051            new ExifTag(TAG_SCENE_TYPE, 41729, IFD_FORMAT_UNDEFINED),
1052            new ExifTag(TAG_CFA_PATTERN, 41730, IFD_FORMAT_UNDEFINED),
1053            new ExifTag(TAG_CUSTOM_RENDERED, 41985, IFD_FORMAT_USHORT),
1054            new ExifTag(TAG_EXPOSURE_MODE, 41986, IFD_FORMAT_USHORT),
1055            new ExifTag(TAG_WHITE_BALANCE, 41987, IFD_FORMAT_USHORT),
1056            new ExifTag(TAG_DIGITAL_ZOOM_RATIO, 41988, IFD_FORMAT_URATIONAL),
1057            new ExifTag(TAG_FOCAL_LENGTH_IN_35MM_FILM, 41989, IFD_FORMAT_USHORT),
1058            new ExifTag(TAG_SCENE_CAPTURE_TYPE, 41990, IFD_FORMAT_USHORT),
1059            new ExifTag(TAG_GAIN_CONTROL, 41991, IFD_FORMAT_USHORT),
1060            new ExifTag(TAG_CONTRAST, 41992, IFD_FORMAT_USHORT),
1061            new ExifTag(TAG_SATURATION, 41993, IFD_FORMAT_USHORT),
1062            new ExifTag(TAG_SHARPNESS, 41994, IFD_FORMAT_USHORT),
1063            new ExifTag(TAG_DEVICE_SETTING_DESCRIPTION, 41995, IFD_FORMAT_UNDEFINED),
1064            new ExifTag(TAG_SUBJECT_DISTANCE_RANGE, 41996, IFD_FORMAT_USHORT),
1065            new ExifTag(TAG_IMAGE_UNIQUE_ID, 42016, IFD_FORMAT_STRING),
1066            new ExifTag(TAG_DNG_VERSION, 50706, IFD_FORMAT_BYTE),
1067            new ExifTag(TAG_DEFAULT_CROP_SIZE, 50720, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG)
1068    };
1069
1070    // Primary image IFD GPS Info tags (See JEITA CP-3451C Section 4.6.8 Tag Support Levels)
1071    private static final ExifTag[] IFD_GPS_TAGS = new ExifTag[] {
1072            new ExifTag(TAG_GPS_VERSION_ID, 0, IFD_FORMAT_BYTE),
1073            new ExifTag(TAG_GPS_LATITUDE_REF, 1, IFD_FORMAT_STRING),
1074            new ExifTag(TAG_GPS_LATITUDE, 2, IFD_FORMAT_URATIONAL),
1075            new ExifTag(TAG_GPS_LONGITUDE_REF, 3, IFD_FORMAT_STRING),
1076            new ExifTag(TAG_GPS_LONGITUDE, 4, IFD_FORMAT_URATIONAL),
1077            new ExifTag(TAG_GPS_ALTITUDE_REF, 5, IFD_FORMAT_BYTE),
1078            new ExifTag(TAG_GPS_ALTITUDE, 6, IFD_FORMAT_URATIONAL),
1079            new ExifTag(TAG_GPS_TIMESTAMP, 7, IFD_FORMAT_URATIONAL),
1080            new ExifTag(TAG_GPS_SATELLITES, 8, IFD_FORMAT_STRING),
1081            new ExifTag(TAG_GPS_STATUS, 9, IFD_FORMAT_STRING),
1082            new ExifTag(TAG_GPS_MEASURE_MODE, 10, IFD_FORMAT_STRING),
1083            new ExifTag(TAG_GPS_DOP, 11, IFD_FORMAT_URATIONAL),
1084            new ExifTag(TAG_GPS_SPEED_REF, 12, IFD_FORMAT_STRING),
1085            new ExifTag(TAG_GPS_SPEED, 13, IFD_FORMAT_URATIONAL),
1086            new ExifTag(TAG_GPS_TRACK_REF, 14, IFD_FORMAT_STRING),
1087            new ExifTag(TAG_GPS_TRACK, 15, IFD_FORMAT_URATIONAL),
1088            new ExifTag(TAG_GPS_IMG_DIRECTION_REF, 16, IFD_FORMAT_STRING),
1089            new ExifTag(TAG_GPS_IMG_DIRECTION, 17, IFD_FORMAT_URATIONAL),
1090            new ExifTag(TAG_GPS_MAP_DATUM, 18, IFD_FORMAT_STRING),
1091            new ExifTag(TAG_GPS_DEST_LATITUDE_REF, 19, IFD_FORMAT_STRING),
1092            new ExifTag(TAG_GPS_DEST_LATITUDE, 20, IFD_FORMAT_URATIONAL),
1093            new ExifTag(TAG_GPS_DEST_LONGITUDE_REF, 21, IFD_FORMAT_STRING),
1094            new ExifTag(TAG_GPS_DEST_LONGITUDE, 22, IFD_FORMAT_URATIONAL),
1095            new ExifTag(TAG_GPS_DEST_BEARING_REF, 23, IFD_FORMAT_STRING),
1096            new ExifTag(TAG_GPS_DEST_BEARING, 24, IFD_FORMAT_URATIONAL),
1097            new ExifTag(TAG_GPS_DEST_DISTANCE_REF, 25, IFD_FORMAT_STRING),
1098            new ExifTag(TAG_GPS_DEST_DISTANCE, 26, IFD_FORMAT_URATIONAL),
1099            new ExifTag(TAG_GPS_PROCESSING_METHOD, 27, IFD_FORMAT_UNDEFINED),
1100            new ExifTag(TAG_GPS_AREA_INFORMATION, 28, IFD_FORMAT_UNDEFINED),
1101            new ExifTag(TAG_GPS_DATESTAMP, 29, IFD_FORMAT_STRING),
1102            new ExifTag(TAG_GPS_DIFFERENTIAL, 30, IFD_FORMAT_USHORT)
1103    };
1104    // Primary image IFD Interoperability tag (See JEITA CP-3451C Section 4.6.8 Tag Support Levels)
1105    private static final ExifTag[] IFD_INTEROPERABILITY_TAGS = new ExifTag[] {
1106            new ExifTag(TAG_INTEROPERABILITY_INDEX, 1, IFD_FORMAT_STRING)
1107    };
1108    // IFD Thumbnail tags (See JEITA CP-3451C Section 4.6.8 Tag Support Levels)
1109    private static final ExifTag[] IFD_THUMBNAIL_TAGS = new ExifTag[] {
1110            // For below two, see TIFF 6.0 Spec Section 3: Bilevel Images.
1111            new ExifTag(TAG_NEW_SUBFILE_TYPE, 254, IFD_FORMAT_ULONG),
1112            new ExifTag(TAG_SUBFILE_TYPE, 255, IFD_FORMAT_ULONG),
1113            new ExifTag(TAG_THUMBNAIL_IMAGE_WIDTH, 256, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
1114            new ExifTag(TAG_THUMBNAIL_IMAGE_LENGTH, 257, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
1115            new ExifTag(TAG_BITS_PER_SAMPLE, 258, IFD_FORMAT_USHORT),
1116            new ExifTag(TAG_COMPRESSION, 259, IFD_FORMAT_USHORT),
1117            new ExifTag(TAG_PHOTOMETRIC_INTERPRETATION, 262, IFD_FORMAT_USHORT),
1118            new ExifTag(TAG_IMAGE_DESCRIPTION, 270, IFD_FORMAT_STRING),
1119            new ExifTag(TAG_MAKE, 271, IFD_FORMAT_STRING),
1120            new ExifTag(TAG_MODEL, 272, IFD_FORMAT_STRING),
1121            new ExifTag(TAG_STRIP_OFFSETS, 273, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
1122            new ExifTag(TAG_ORIENTATION, 274, IFD_FORMAT_USHORT),
1123            new ExifTag(TAG_SAMPLES_PER_PIXEL, 277, IFD_FORMAT_USHORT),
1124            new ExifTag(TAG_ROWS_PER_STRIP, 278, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
1125            new ExifTag(TAG_STRIP_BYTE_COUNTS, 279, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG),
1126            new ExifTag(TAG_X_RESOLUTION, 282, IFD_FORMAT_URATIONAL),
1127            new ExifTag(TAG_Y_RESOLUTION, 283, IFD_FORMAT_URATIONAL),
1128            new ExifTag(TAG_PLANAR_CONFIGURATION, 284, IFD_FORMAT_USHORT),
1129            new ExifTag(TAG_RESOLUTION_UNIT, 296, IFD_FORMAT_USHORT),
1130            new ExifTag(TAG_TRANSFER_FUNCTION, 301, IFD_FORMAT_USHORT),
1131            new ExifTag(TAG_SOFTWARE, 305, IFD_FORMAT_STRING),
1132            new ExifTag(TAG_DATETIME, 306, IFD_FORMAT_STRING),
1133            new ExifTag(TAG_ARTIST, 315, IFD_FORMAT_STRING),
1134            new ExifTag(TAG_WHITE_POINT, 318, IFD_FORMAT_URATIONAL),
1135            new ExifTag(TAG_PRIMARY_CHROMATICITIES, 319, IFD_FORMAT_URATIONAL),
1136            // See Adobe PageMaker® 6.0 TIFF Technical Notes, Note 1.
1137            new ExifTag(TAG_SUB_IFD_POINTER, 330, IFD_FORMAT_ULONG),
1138            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT, 513, IFD_FORMAT_ULONG),
1139            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH, 514, IFD_FORMAT_ULONG),
1140            new ExifTag(TAG_Y_CB_CR_COEFFICIENTS, 529, IFD_FORMAT_URATIONAL),
1141            new ExifTag(TAG_Y_CB_CR_SUB_SAMPLING, 530, IFD_FORMAT_USHORT),
1142            new ExifTag(TAG_Y_CB_CR_POSITIONING, 531, IFD_FORMAT_USHORT),
1143            new ExifTag(TAG_REFERENCE_BLACK_WHITE, 532, IFD_FORMAT_URATIONAL),
1144            new ExifTag(TAG_COPYRIGHT, 33432, IFD_FORMAT_STRING),
1145            new ExifTag(TAG_EXIF_IFD_POINTER, 34665, IFD_FORMAT_ULONG),
1146            new ExifTag(TAG_GPS_INFO_IFD_POINTER, 34853, IFD_FORMAT_ULONG),
1147            new ExifTag(TAG_DNG_VERSION, 50706, IFD_FORMAT_BYTE),
1148            new ExifTag(TAG_DEFAULT_CROP_SIZE, 50720, IFD_FORMAT_USHORT, IFD_FORMAT_ULONG)
1149    };
1150
1151    // RAF file tag (See piex.cc line 372)
1152    private static final ExifTag TAG_RAF_IMAGE_SIZE =
1153            new ExifTag(TAG_STRIP_OFFSETS, 273, IFD_FORMAT_USHORT);
1154
1155    // ORF file tags (See http://www.exiv2.org/tags-olympus.html)
1156    private static final ExifTag[] ORF_MAKER_NOTE_TAGS = new ExifTag[] {
1157            new ExifTag(TAG_ORF_THUMBNAIL_IMAGE, 256, IFD_FORMAT_UNDEFINED),
1158            new ExifTag(TAG_ORF_CAMERA_SETTINGS_IFD_POINTER, 8224, IFD_FORMAT_ULONG),
1159            new ExifTag(TAG_ORF_IMAGE_PROCESSING_IFD_POINTER, 8256, IFD_FORMAT_ULONG)
1160    };
1161    private static final ExifTag[] ORF_CAMERA_SETTINGS_TAGS = new ExifTag[] {
1162            new ExifTag(TAG_ORF_PREVIEW_IMAGE_START, 257, IFD_FORMAT_ULONG),
1163            new ExifTag(TAG_ORF_PREVIEW_IMAGE_LENGTH, 258, IFD_FORMAT_ULONG)
1164    };
1165    private static final ExifTag[] ORF_IMAGE_PROCESSING_TAGS = new ExifTag[] {
1166            new ExifTag(TAG_ORF_ASPECT_FRAME, 4371, IFD_FORMAT_USHORT)
1167    };
1168    // PEF file tag (See http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/Pentax.html)
1169    private static final ExifTag[] PEF_TAGS = new ExifTag[] {
1170            new ExifTag(TAG_COLOR_SPACE, 55, IFD_FORMAT_USHORT)
1171    };
1172
1173    // See JEITA CP-3451C Section 4.6.3: Exif-specific IFD.
1174    // The following values are used for indicating pointers to the other Image File Directories.
1175
1176    // Indices of Exif Ifd tag groups
1177    /** @hide */
1178    @Retention(RetentionPolicy.SOURCE)
1179    @IntDef({IFD_TYPE_PRIMARY, IFD_TYPE_EXIF, IFD_TYPE_GPS, IFD_TYPE_INTEROPERABILITY,
1180            IFD_TYPE_THUMBNAIL, IFD_TYPE_PREVIEW, IFD_TYPE_ORF_MAKER_NOTE,
1181            IFD_TYPE_ORF_CAMERA_SETTINGS, IFD_TYPE_ORF_IMAGE_PROCESSING, IFD_TYPE_PEF})
1182    public @interface IfdType {}
1183
1184    private static final int IFD_TYPE_PRIMARY = 0;
1185    private static final int IFD_TYPE_EXIF = 1;
1186    private static final int IFD_TYPE_GPS = 2;
1187    private static final int IFD_TYPE_INTEROPERABILITY = 3;
1188    private static final int IFD_TYPE_THUMBNAIL = 4;
1189    private static final int IFD_TYPE_PREVIEW = 5;
1190    private static final int IFD_TYPE_ORF_MAKER_NOTE = 6;
1191    private static final int IFD_TYPE_ORF_CAMERA_SETTINGS = 7;
1192    private static final int IFD_TYPE_ORF_IMAGE_PROCESSING = 8;
1193    private static final int IFD_TYPE_PEF = 9;
1194
1195    // List of Exif tag groups
1196    private static final ExifTag[][] EXIF_TAGS = new ExifTag[][] {
1197            IFD_TIFF_TAGS, IFD_EXIF_TAGS, IFD_GPS_TAGS, IFD_INTEROPERABILITY_TAGS,
1198            IFD_THUMBNAIL_TAGS, IFD_TIFF_TAGS, ORF_MAKER_NOTE_TAGS, ORF_CAMERA_SETTINGS_TAGS,
1199            ORF_IMAGE_PROCESSING_TAGS, PEF_TAGS
1200    };
1201    // List of tags for pointing to the other image file directory offset.
1202    private static final ExifTag[] EXIF_POINTER_TAGS = new ExifTag[] {
1203            new ExifTag(TAG_SUB_IFD_POINTER, 330, IFD_FORMAT_ULONG),
1204            new ExifTag(TAG_EXIF_IFD_POINTER, 34665, IFD_FORMAT_ULONG),
1205            new ExifTag(TAG_GPS_INFO_IFD_POINTER, 34853, IFD_FORMAT_ULONG),
1206            new ExifTag(TAG_INTEROPERABILITY_IFD_POINTER, 40965, IFD_FORMAT_ULONG),
1207            new ExifTag(TAG_ORF_CAMERA_SETTINGS_IFD_POINTER, 8224, IFD_FORMAT_BYTE),
1208            new ExifTag(TAG_ORF_IMAGE_PROCESSING_IFD_POINTER, 8256, IFD_FORMAT_BYTE)
1209    };
1210
1211    // Tags for indicating the thumbnail offset and length
1212    private static final ExifTag JPEG_INTERCHANGE_FORMAT_TAG =
1213            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT, 513, IFD_FORMAT_ULONG);
1214    private static final ExifTag JPEG_INTERCHANGE_FORMAT_LENGTH_TAG =
1215            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH, 514, IFD_FORMAT_ULONG);
1216
1217    // Mappings from tag number to tag name and each item represents one IFD tag group.
1218    private static final HashMap[] sExifTagMapsForReading = new HashMap[EXIF_TAGS.length];
1219    // Mappings from tag name to tag number and each item represents one IFD tag group.
1220    private static final HashMap[] sExifTagMapsForWriting = new HashMap[EXIF_TAGS.length];
1221    private static final HashSet<String> sTagSetForCompatibility = new HashSet<>(Arrays.asList(
1222            TAG_F_NUMBER, TAG_DIGITAL_ZOOM_RATIO, TAG_EXPOSURE_TIME, TAG_SUBJECT_DISTANCE,
1223            TAG_GPS_TIMESTAMP));
1224    // Mappings from tag number to IFD type for pointer tags.
1225    private static final HashMap sExifPointerTagMap = new HashMap();
1226
1227    // See JPEG File Interchange Format Version 1.02.
1228    // The following values are defined for handling JPEG streams. In this implementation, we are
1229    // not only getting information from EXIF but also from some JPEG special segments such as
1230    // MARKER_COM for user comment and MARKER_SOFx for image width and height.
1231
1232    private static final Charset ASCII = Charset.forName("US-ASCII");
1233    // Identifier for EXIF APP1 segment in JPEG
1234    private static final byte[] IDENTIFIER_EXIF_APP1 = "Exif\0\0".getBytes(ASCII);
1235    // JPEG segment markers, that each marker consumes two bytes beginning with 0xff and ending with
1236    // the indicator. There is no SOF4, SOF8, SOF16 markers in JPEG and SOFx markers indicates start
1237    // of frame(baseline DCT) and the image size info exists in its beginning part.
1238    private static final byte MARKER = (byte) 0xff;
1239    private static final byte MARKER_SOI = (byte) 0xd8;
1240    private static final byte MARKER_SOF0 = (byte) 0xc0;
1241    private static final byte MARKER_SOF1 = (byte) 0xc1;
1242    private static final byte MARKER_SOF2 = (byte) 0xc2;
1243    private static final byte MARKER_SOF3 = (byte) 0xc3;
1244    private static final byte MARKER_SOF5 = (byte) 0xc5;
1245    private static final byte MARKER_SOF6 = (byte) 0xc6;
1246    private static final byte MARKER_SOF7 = (byte) 0xc7;
1247    private static final byte MARKER_SOF9 = (byte) 0xc9;
1248    private static final byte MARKER_SOF10 = (byte) 0xca;
1249    private static final byte MARKER_SOF11 = (byte) 0xcb;
1250    private static final byte MARKER_SOF13 = (byte) 0xcd;
1251    private static final byte MARKER_SOF14 = (byte) 0xce;
1252    private static final byte MARKER_SOF15 = (byte) 0xcf;
1253    private static final byte MARKER_SOS = (byte) 0xda;
1254    private static final byte MARKER_APP1 = (byte) 0xe1;
1255    private static final byte MARKER_COM = (byte) 0xfe;
1256    private static final byte MARKER_EOI = (byte) 0xd9;
1257
1258    // Supported Image File Types
1259    private static final int IMAGE_TYPE_UNKNOWN = 0;
1260    private static final int IMAGE_TYPE_ARW = 1;
1261    private static final int IMAGE_TYPE_CR2 = 2;
1262    private static final int IMAGE_TYPE_DNG = 3;
1263    private static final int IMAGE_TYPE_JPEG = 4;
1264    private static final int IMAGE_TYPE_NEF = 5;
1265    private static final int IMAGE_TYPE_NRW = 6;
1266    private static final int IMAGE_TYPE_ORF = 7;
1267    private static final int IMAGE_TYPE_PEF = 8;
1268    private static final int IMAGE_TYPE_RAF = 9;
1269    private static final int IMAGE_TYPE_RW2 = 10;
1270    private static final int IMAGE_TYPE_SRW = 11;
1271    private static final int IMAGE_TYPE_HEIF = 12;
1272
1273    static {
1274        sFormatter = new SimpleDateFormat("yyyy:MM:dd HH:mm:ss");
1275        sFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));
1276
1277        // Build up the hash tables to look up Exif tags for reading Exif tags.
1278        for (int ifdType = 0; ifdType < EXIF_TAGS.length; ++ifdType) {
1279            sExifTagMapsForReading[ifdType] = new HashMap();
1280            sExifTagMapsForWriting[ifdType] = new HashMap();
1281            for (ExifTag tag : EXIF_TAGS[ifdType]) {
1282                sExifTagMapsForReading[ifdType].put(tag.number, tag);
1283                sExifTagMapsForWriting[ifdType].put(tag.name, tag);
1284            }
1285        }
1286
1287        // Build up the hash table to look up Exif pointer tags.
1288        sExifPointerTagMap.put(EXIF_POINTER_TAGS[0].number, IFD_TYPE_PREVIEW); // 330
1289        sExifPointerTagMap.put(EXIF_POINTER_TAGS[1].number, IFD_TYPE_EXIF); // 34665
1290        sExifPointerTagMap.put(EXIF_POINTER_TAGS[2].number, IFD_TYPE_GPS); // 34853
1291        sExifPointerTagMap.put(EXIF_POINTER_TAGS[3].number, IFD_TYPE_INTEROPERABILITY); // 40965
1292        sExifPointerTagMap.put(EXIF_POINTER_TAGS[4].number, IFD_TYPE_ORF_CAMERA_SETTINGS); // 8224
1293        sExifPointerTagMap.put(EXIF_POINTER_TAGS[5].number, IFD_TYPE_ORF_IMAGE_PROCESSING); // 8256
1294    }
1295
1296    private final String mFilename;
1297    private final FileDescriptor mSeekableFileDescriptor;
1298    private final AssetManager.AssetInputStream mAssetInputStream;
1299    private final boolean mIsInputStream;
1300    private int mMimeType;
1301    private final HashMap[] mAttributes = new HashMap[EXIF_TAGS.length];
1302    private ByteOrder mExifByteOrder = ByteOrder.BIG_ENDIAN;
1303    private boolean mHasThumbnail;
1304    // The following values used for indicating a thumbnail position.
1305    private int mThumbnailOffset;
1306    private int mThumbnailLength;
1307    private byte[] mThumbnailBytes;
1308    private int mThumbnailCompression;
1309    private int mExifOffset;
1310    private int mOrfMakerNoteOffset;
1311    private int mOrfThumbnailOffset;
1312    private int mOrfThumbnailLength;
1313    private int mRw2JpgFromRawOffset;
1314    private boolean mIsSupportedFile;
1315
1316    // Pattern to check non zero timestamp
1317    private static final Pattern sNonZeroTimePattern = Pattern.compile(".*[1-9].*");
1318    // Pattern to check gps timestamp
1319    private static final Pattern sGpsTimestampPattern =
1320            Pattern.compile("^([0-9][0-9]):([0-9][0-9]):([0-9][0-9])$");
1321
1322    /**
1323     * Reads Exif tags from the specified image file.
1324     */
1325    public ExifInterface(String filename) throws IOException {
1326        if (filename == null) {
1327            throw new IllegalArgumentException("filename cannot be null");
1328        }
1329        FileInputStream in = null;
1330        mAssetInputStream = null;
1331        mFilename = filename;
1332        mIsInputStream = false;
1333        try {
1334            in = new FileInputStream(filename);
1335            if (isSeekableFD(in.getFD())) {
1336                mSeekableFileDescriptor = in.getFD();
1337            } else {
1338                mSeekableFileDescriptor = null;
1339            }
1340            loadAttributes(in);
1341        } finally {
1342            IoUtils.closeQuietly(in);
1343        }
1344    }
1345
1346    /**
1347     * Reads Exif tags from the specified image file descriptor. Attribute mutation is supported
1348     * for writable and seekable file descriptors only. This constructor will not rewind the offset
1349     * of the given file descriptor. Developers should close the file descriptor after use.
1350     */
1351    public ExifInterface(FileDescriptor fileDescriptor) throws IOException {
1352        if (fileDescriptor == null) {
1353            throw new IllegalArgumentException("fileDescriptor cannot be null");
1354        }
1355        mAssetInputStream = null;
1356        mFilename = null;
1357        if (isSeekableFD(fileDescriptor)) {
1358            mSeekableFileDescriptor = fileDescriptor;
1359            // Keep the original file descriptor in order to save attributes when it's seekable.
1360            // Otherwise, just close the given file descriptor after reading it because the save
1361            // feature won't be working.
1362            try {
1363                fileDescriptor = Os.dup(fileDescriptor);
1364            } catch (ErrnoException e) {
1365                throw e.rethrowAsIOException();
1366            }
1367        } else {
1368            mSeekableFileDescriptor = null;
1369        }
1370        mIsInputStream = false;
1371        FileInputStream in = null;
1372        try {
1373            in = new FileInputStream(fileDescriptor);
1374            loadAttributes(in);
1375        } finally {
1376            IoUtils.closeQuietly(in);
1377        }
1378    }
1379
1380    /**
1381     * Reads Exif tags from the specified image input stream. Attribute mutation is not supported
1382     * for input streams. The given input stream will proceed its current position. Developers
1383     * should close the input stream after use.
1384     */
1385    public ExifInterface(InputStream inputStream) throws IOException {
1386        if (inputStream == null) {
1387            throw new IllegalArgumentException("inputStream cannot be null");
1388        }
1389        mFilename = null;
1390        if (inputStream instanceof AssetManager.AssetInputStream) {
1391            mAssetInputStream = (AssetManager.AssetInputStream) inputStream;
1392            mSeekableFileDescriptor = null;
1393        } else if (inputStream instanceof FileInputStream
1394                && isSeekableFD(((FileInputStream) inputStream).getFD())) {
1395            mAssetInputStream = null;
1396            mSeekableFileDescriptor = ((FileInputStream) inputStream).getFD();
1397        } else {
1398            mAssetInputStream = null;
1399            mSeekableFileDescriptor = null;
1400        }
1401        mIsInputStream = true;
1402        loadAttributes(inputStream);
1403    }
1404
1405    /**
1406     * Returns the EXIF attribute of the specified tag or {@code null} if there is no such tag in
1407     * the image file.
1408     *
1409     * @param tag the name of the tag.
1410     */
1411    private ExifAttribute getExifAttribute(String tag) {
1412        // Retrieves all tag groups. The value from primary image tag group has a higher priority
1413        // than the value from the thumbnail tag group if there are more than one candidates.
1414        for (int i = 0; i < EXIF_TAGS.length; ++i) {
1415            Object value = mAttributes[i].get(tag);
1416            if (value != null) {
1417                return (ExifAttribute) value;
1418            }
1419        }
1420        return null;
1421    }
1422
1423    /**
1424     * Returns the value of the specified tag or {@code null} if there
1425     * is no such tag in the image file.
1426     *
1427     * @param tag the name of the tag.
1428     */
1429    public String getAttribute(String tag) {
1430        ExifAttribute attribute = getExifAttribute(tag);
1431        if (attribute != null) {
1432            if (!sTagSetForCompatibility.contains(tag)) {
1433                return attribute.getStringValue(mExifByteOrder);
1434            }
1435            if (tag.equals(TAG_GPS_TIMESTAMP)) {
1436                // Convert the rational values to the custom formats for backwards compatibility.
1437                if (attribute.format != IFD_FORMAT_URATIONAL
1438                        && attribute.format != IFD_FORMAT_SRATIONAL) {
1439                    return null;
1440                }
1441                Rational[] array = (Rational[]) attribute.getValue(mExifByteOrder);
1442                if (array.length != 3) {
1443                    return null;
1444                }
1445                return String.format("%02d:%02d:%02d",
1446                        (int) ((float) array[0].numerator / array[0].denominator),
1447                        (int) ((float) array[1].numerator / array[1].denominator),
1448                        (int) ((float) array[2].numerator / array[2].denominator));
1449            }
1450            try {
1451                return Double.toString(attribute.getDoubleValue(mExifByteOrder));
1452            } catch (NumberFormatException e) {
1453                return null;
1454            }
1455        }
1456        return null;
1457    }
1458
1459    /**
1460     * Returns the integer value of the specified tag. If there is no such tag
1461     * in the image file or the value cannot be parsed as integer, return
1462     * <var>defaultValue</var>.
1463     *
1464     * @param tag the name of the tag.
1465     * @param defaultValue the value to return if the tag is not available.
1466     */
1467    public int getAttributeInt(String tag, int defaultValue) {
1468        ExifAttribute exifAttribute = getExifAttribute(tag);
1469        if (exifAttribute == null) {
1470            return defaultValue;
1471        }
1472
1473        try {
1474            return exifAttribute.getIntValue(mExifByteOrder);
1475        } catch (NumberFormatException e) {
1476            return defaultValue;
1477        }
1478    }
1479
1480    /**
1481     * Returns the double value of the tag that is specified as rational or contains a
1482     * double-formatted value. If there is no such tag in the image file or the value cannot be
1483     * parsed as double, return <var>defaultValue</var>.
1484     *
1485     * @param tag the name of the tag.
1486     * @param defaultValue the value to return if the tag is not available.
1487     */
1488    public double getAttributeDouble(String tag, double defaultValue) {
1489        ExifAttribute exifAttribute = getExifAttribute(tag);
1490        if (exifAttribute == null) {
1491            return defaultValue;
1492        }
1493
1494        try {
1495            return exifAttribute.getDoubleValue(mExifByteOrder);
1496        } catch (NumberFormatException e) {
1497            return defaultValue;
1498        }
1499    }
1500
1501    /**
1502     * Set the value of the specified tag.
1503     *
1504     * @param tag the name of the tag.
1505     * @param value the value of the tag.
1506     */
1507    public void setAttribute(String tag, String value) {
1508        // Convert the given value to rational values for backwards compatibility.
1509        if (value != null && sTagSetForCompatibility.contains(tag)) {
1510            if (tag.equals(TAG_GPS_TIMESTAMP)) {
1511                Matcher m = sGpsTimestampPattern.matcher(value);
1512                if (!m.find()) {
1513                    Log.w(TAG, "Invalid value for " + tag + " : " + value);
1514                    return;
1515                }
1516                value = Integer.parseInt(m.group(1)) + "/1," + Integer.parseInt(m.group(2)) + "/1,"
1517                        + Integer.parseInt(m.group(3)) + "/1";
1518            } else {
1519                try {
1520                    double doubleValue = Double.parseDouble(value);
1521                    value = (long) (doubleValue * 10000L) + "/10000";
1522                } catch (NumberFormatException e) {
1523                    Log.w(TAG, "Invalid value for " + tag + " : " + value);
1524                    return;
1525                }
1526            }
1527        }
1528
1529        for (int i = 0 ; i < EXIF_TAGS.length; ++i) {
1530            if (i == IFD_TYPE_THUMBNAIL && !mHasThumbnail) {
1531                continue;
1532            }
1533            final Object obj = sExifTagMapsForWriting[i].get(tag);
1534            if (obj != null) {
1535                if (value == null) {
1536                    mAttributes[i].remove(tag);
1537                    continue;
1538                }
1539                final ExifTag exifTag = (ExifTag) obj;
1540                Pair<Integer, Integer> guess = guessDataFormat(value);
1541                int dataFormat;
1542                if (exifTag.primaryFormat == guess.first || exifTag.primaryFormat == guess.second) {
1543                    dataFormat = exifTag.primaryFormat;
1544                } else if (exifTag.secondaryFormat != -1 && (exifTag.secondaryFormat == guess.first
1545                        || exifTag.secondaryFormat == guess.second)) {
1546                    dataFormat = exifTag.secondaryFormat;
1547                } else if (exifTag.primaryFormat == IFD_FORMAT_BYTE
1548                        || exifTag.primaryFormat == IFD_FORMAT_UNDEFINED
1549                        || exifTag.primaryFormat == IFD_FORMAT_STRING) {
1550                    dataFormat = exifTag.primaryFormat;
1551                } else {
1552                    Log.w(TAG, "Given tag (" + tag + ") value didn't match with one of expected "
1553                            + "formats: " + IFD_FORMAT_NAMES[exifTag.primaryFormat]
1554                            + (exifTag.secondaryFormat == -1 ? "" : ", "
1555                            + IFD_FORMAT_NAMES[exifTag.secondaryFormat]) + " (guess: "
1556                            + IFD_FORMAT_NAMES[guess.first] + (guess.second == -1 ? "" : ", "
1557                            + IFD_FORMAT_NAMES[guess.second]) + ")");
1558                    continue;
1559                }
1560                switch (dataFormat) {
1561                    case IFD_FORMAT_BYTE: {
1562                        mAttributes[i].put(tag, ExifAttribute.createByte(value));
1563                        break;
1564                    }
1565                    case IFD_FORMAT_UNDEFINED:
1566                    case IFD_FORMAT_STRING: {
1567                        mAttributes[i].put(tag, ExifAttribute.createString(value));
1568                        break;
1569                    }
1570                    case IFD_FORMAT_USHORT: {
1571                        final String[] values = value.split(",");
1572                        final int[] intArray = new int[values.length];
1573                        for (int j = 0; j < values.length; ++j) {
1574                            intArray[j] = Integer.parseInt(values[j]);
1575                        }
1576                        mAttributes[i].put(tag,
1577                                ExifAttribute.createUShort(intArray, mExifByteOrder));
1578                        break;
1579                    }
1580                    case IFD_FORMAT_SLONG: {
1581                        final String[] values = value.split(",");
1582                        final int[] intArray = new int[values.length];
1583                        for (int j = 0; j < values.length; ++j) {
1584                            intArray[j] = Integer.parseInt(values[j]);
1585                        }
1586                        mAttributes[i].put(tag,
1587                                ExifAttribute.createSLong(intArray, mExifByteOrder));
1588                        break;
1589                    }
1590                    case IFD_FORMAT_ULONG: {
1591                        final String[] values = value.split(",");
1592                        final long[] longArray = new long[values.length];
1593                        for (int j = 0; j < values.length; ++j) {
1594                            longArray[j] = Long.parseLong(values[j]);
1595                        }
1596                        mAttributes[i].put(tag,
1597                                ExifAttribute.createULong(longArray, mExifByteOrder));
1598                        break;
1599                    }
1600                    case IFD_FORMAT_URATIONAL: {
1601                        final String[] values = value.split(",");
1602                        final Rational[] rationalArray = new Rational[values.length];
1603                        for (int j = 0; j < values.length; ++j) {
1604                            final String[] numbers = values[j].split("/");
1605                            rationalArray[j] = new Rational((long) Double.parseDouble(numbers[0]),
1606                                    (long) Double.parseDouble(numbers[1]));
1607                        }
1608                        mAttributes[i].put(tag,
1609                                ExifAttribute.createURational(rationalArray, mExifByteOrder));
1610                        break;
1611                    }
1612                    case IFD_FORMAT_SRATIONAL: {
1613                        final String[] values = value.split(",");
1614                        final Rational[] rationalArray = new Rational[values.length];
1615                        for (int j = 0; j < values.length; ++j) {
1616                            final String[] numbers = values[j].split("/");
1617                            rationalArray[j] = new Rational((long) Double.parseDouble(numbers[0]),
1618                                    (long) Double.parseDouble(numbers[1]));
1619                        }
1620                        mAttributes[i].put(tag,
1621                                ExifAttribute.createSRational(rationalArray, mExifByteOrder));
1622                        break;
1623                    }
1624                    case IFD_FORMAT_DOUBLE: {
1625                        final String[] values = value.split(",");
1626                        final double[] doubleArray = new double[values.length];
1627                        for (int j = 0; j < values.length; ++j) {
1628                            doubleArray[j] = Double.parseDouble(values[j]);
1629                        }
1630                        mAttributes[i].put(tag,
1631                                ExifAttribute.createDouble(doubleArray, mExifByteOrder));
1632                        break;
1633                    }
1634                    default:
1635                        Log.w(TAG, "Data format isn't one of expected formats: " + dataFormat);
1636                        continue;
1637                }
1638            }
1639        }
1640    }
1641
1642    /**
1643     * Update the values of the tags in the tag groups if any value for the tag already was stored.
1644     *
1645     * @param tag the name of the tag.
1646     * @param value the value of the tag in a form of {@link ExifAttribute}.
1647     * @return Returns {@code true} if updating is placed.
1648     */
1649    private boolean updateAttribute(String tag, ExifAttribute value) {
1650        boolean updated = false;
1651        for (int i = 0 ; i < EXIF_TAGS.length; ++i) {
1652            if (mAttributes[i].containsKey(tag)) {
1653                mAttributes[i].put(tag, value);
1654                updated = true;
1655            }
1656        }
1657        return updated;
1658    }
1659
1660    /**
1661     * Remove any values of the specified tag.
1662     *
1663     * @param tag the name of the tag.
1664     */
1665    private void removeAttribute(String tag) {
1666        for (int i = 0 ; i < EXIF_TAGS.length; ++i) {
1667            mAttributes[i].remove(tag);
1668        }
1669    }
1670
1671    /**
1672     * This function decides which parser to read the image data according to the given input stream
1673     * type and the content of the input stream. In each case, it reads the first three bytes to
1674     * determine whether the image data format is JPEG or not.
1675     */
1676    private void loadAttributes(@NonNull InputStream in) throws IOException {
1677        try {
1678            // Initialize mAttributes.
1679            for (int i = 0; i < EXIF_TAGS.length; ++i) {
1680                mAttributes[i] = new HashMap();
1681            }
1682
1683            // Check file type
1684            in = new BufferedInputStream(in, SIGNATURE_CHECK_SIZE);
1685            mMimeType = getMimeType((BufferedInputStream) in);
1686
1687            // Create byte-ordered input stream
1688            ByteOrderedDataInputStream inputStream = new ByteOrderedDataInputStream(in);
1689
1690            switch (mMimeType) {
1691                case IMAGE_TYPE_JPEG: {
1692                    getJpegAttributes(inputStream, 0, IFD_TYPE_PRIMARY); // 0 is offset
1693                    break;
1694                }
1695                case IMAGE_TYPE_RAF: {
1696                    getRafAttributes(inputStream);
1697                    break;
1698                }
1699                case IMAGE_TYPE_HEIF: {
1700                    getHeifAttributes(inputStream);
1701                    break;
1702                }
1703                case IMAGE_TYPE_ORF: {
1704                    getOrfAttributes(inputStream);
1705                    break;
1706                }
1707                case IMAGE_TYPE_RW2: {
1708                    getRw2Attributes(inputStream);
1709                    break;
1710                }
1711                case IMAGE_TYPE_ARW:
1712                case IMAGE_TYPE_CR2:
1713                case IMAGE_TYPE_DNG:
1714                case IMAGE_TYPE_NEF:
1715                case IMAGE_TYPE_NRW:
1716                case IMAGE_TYPE_PEF:
1717                case IMAGE_TYPE_SRW:
1718                case IMAGE_TYPE_UNKNOWN: {
1719                    getRawAttributes(inputStream);
1720                    break;
1721                }
1722                default: {
1723                    break;
1724                }
1725            }
1726            // Set thumbnail image offset and length
1727            setThumbnailData(inputStream);
1728            mIsSupportedFile = true;
1729        } catch (IOException e) {
1730            // Ignore exceptions in order to keep the compatibility with the old versions of
1731            // ExifInterface.
1732            mIsSupportedFile = false;
1733            if (DEBUG) {
1734                Log.w(TAG, "Invalid image: ExifInterface got an unsupported image format file"
1735                        + "(ExifInterface supports JPEG and some RAW image formats only) "
1736                        + "or a corrupted JPEG file to ExifInterface.", e);
1737            }
1738        } finally {
1739            addDefaultValuesForCompatibility();
1740
1741            if (DEBUG) {
1742                printAttributes();
1743            }
1744        }
1745    }
1746
1747    private static boolean isSeekableFD(FileDescriptor fd) throws IOException {
1748        try {
1749            Os.lseek(fd, 0, OsConstants.SEEK_CUR);
1750            return true;
1751        } catch (ErrnoException e) {
1752            return false;
1753        }
1754    }
1755
1756    // Prints out attributes for debugging.
1757    private void printAttributes() {
1758        for (int i = 0; i < mAttributes.length; ++i) {
1759            Log.d(TAG, "The size of tag group[" + i + "]: " + mAttributes[i].size());
1760            for (Map.Entry entry : (Set<Map.Entry>) mAttributes[i].entrySet()) {
1761                final ExifAttribute tagValue = (ExifAttribute) entry.getValue();
1762                Log.d(TAG, "tagName: " + entry.getKey() + ", tagType: " + tagValue.toString()
1763                        + ", tagValue: '" + tagValue.getStringValue(mExifByteOrder) + "'");
1764            }
1765        }
1766    }
1767
1768    /**
1769     * Save the tag data into the original image file. This is expensive because it involves
1770     * copying all the data from one file to another and deleting the old file and renaming the
1771     * other. It's best to use {@link #setAttribute(String,String)} to set all attributes to write
1772     * and make a single call rather than multiple calls for each attribute.
1773     * <p>
1774     * This method is only supported for JPEG files.
1775     * </p>
1776     */
1777    public void saveAttributes() throws IOException {
1778        if (!mIsSupportedFile || mMimeType != IMAGE_TYPE_JPEG) {
1779            throw new IOException("ExifInterface only supports saving attributes on JPEG formats.");
1780        }
1781        if (mIsInputStream || (mSeekableFileDescriptor == null && mFilename == null)) {
1782            throw new IOException(
1783                    "ExifInterface does not support saving attributes for the current input.");
1784        }
1785
1786        // Keep the thumbnail in memory
1787        mThumbnailBytes = getThumbnail();
1788
1789        FileInputStream in = null;
1790        FileOutputStream out = null;
1791        File tempFile = null;
1792        try {
1793            // Move the original file to temporary file.
1794            if (mFilename != null) {
1795                tempFile = new File(mFilename + ".tmp");
1796                File originalFile = new File(mFilename);
1797                if (!originalFile.renameTo(tempFile)) {
1798                    throw new IOException("Could'nt rename to " + tempFile.getAbsolutePath());
1799                }
1800            } else if (mSeekableFileDescriptor != null) {
1801                tempFile = File.createTempFile("temp", "jpg");
1802                Os.lseek(mSeekableFileDescriptor, 0, OsConstants.SEEK_SET);
1803                in = new FileInputStream(mSeekableFileDescriptor);
1804                out = new FileOutputStream(tempFile);
1805                Streams.copy(in, out);
1806            }
1807        } catch (ErrnoException e) {
1808            throw e.rethrowAsIOException();
1809        } finally {
1810            IoUtils.closeQuietly(in);
1811            IoUtils.closeQuietly(out);
1812        }
1813
1814        in = null;
1815        out = null;
1816        try {
1817            // Save the new file.
1818            in = new FileInputStream(tempFile);
1819            if (mFilename != null) {
1820                out = new FileOutputStream(mFilename);
1821            } else if (mSeekableFileDescriptor != null) {
1822                Os.lseek(mSeekableFileDescriptor, 0, OsConstants.SEEK_SET);
1823                out = new FileOutputStream(mSeekableFileDescriptor);
1824            }
1825            saveJpegAttributes(in, out);
1826        } catch (ErrnoException e) {
1827            throw e.rethrowAsIOException();
1828        } finally {
1829            IoUtils.closeQuietly(in);
1830            IoUtils.closeQuietly(out);
1831            tempFile.delete();
1832        }
1833
1834        // Discard the thumbnail in memory
1835        mThumbnailBytes = null;
1836    }
1837
1838    /**
1839     * Returns true if the image file has a thumbnail.
1840     */
1841    public boolean hasThumbnail() {
1842        return mHasThumbnail;
1843    }
1844
1845    /**
1846     * Returns the JPEG compressed thumbnail inside the image file, or {@code null} if there is no
1847     * JPEG compressed thumbnail.
1848     * The returned data can be decoded using
1849     * {@link android.graphics.BitmapFactory#decodeByteArray(byte[],int,int)}
1850     */
1851    public byte[] getThumbnail() {
1852        if (mThumbnailCompression == DATA_JPEG || mThumbnailCompression == DATA_JPEG_COMPRESSED) {
1853            return getThumbnailBytes();
1854        }
1855        return null;
1856    }
1857
1858    /**
1859     * Returns the thumbnail bytes inside the image file, regardless of the compression type of the
1860     * thumbnail image.
1861     */
1862    public byte[] getThumbnailBytes() {
1863        if (!mHasThumbnail) {
1864            return null;
1865        }
1866        if (mThumbnailBytes != null) {
1867            return mThumbnailBytes;
1868        }
1869
1870        // Read the thumbnail.
1871        InputStream in = null;
1872        try {
1873            if (mAssetInputStream != null) {
1874                in = mAssetInputStream;
1875                if (in.markSupported()) {
1876                    in.reset();
1877                } else {
1878                    Log.d(TAG, "Cannot read thumbnail from inputstream without mark/reset support");
1879                    return null;
1880                }
1881            } else if (mFilename != null) {
1882                in = new FileInputStream(mFilename);
1883            } else if (mSeekableFileDescriptor != null) {
1884                FileDescriptor fileDescriptor = Os.dup(mSeekableFileDescriptor);
1885                Os.lseek(fileDescriptor, 0, OsConstants.SEEK_SET);
1886                in = new FileInputStream(fileDescriptor);
1887            }
1888            if (in == null) {
1889                // Should not be reached this.
1890                throw new FileNotFoundException();
1891            }
1892            if (in.skip(mThumbnailOffset) != mThumbnailOffset) {
1893                throw new IOException("Corrupted image");
1894            }
1895            byte[] buffer = new byte[mThumbnailLength];
1896            if (in.read(buffer) != mThumbnailLength) {
1897                throw new IOException("Corrupted image");
1898            }
1899            mThumbnailBytes = buffer;
1900            return buffer;
1901        } catch (IOException | ErrnoException e) {
1902            // Couldn't get a thumbnail image.
1903            Log.d(TAG, "Encountered exception while getting thumbnail", e);
1904        } finally {
1905            IoUtils.closeQuietly(in);
1906        }
1907        return null;
1908    }
1909
1910    /**
1911     * Creates and returns a Bitmap object of the thumbnail image based on the byte array and the
1912     * thumbnail compression value, or {@code null} if the compression type is unsupported.
1913     */
1914    public Bitmap getThumbnailBitmap() {
1915        if (!mHasThumbnail) {
1916            return null;
1917        } else if (mThumbnailBytes == null) {
1918            mThumbnailBytes = getThumbnailBytes();
1919        }
1920
1921        if (mThumbnailCompression == DATA_JPEG || mThumbnailCompression == DATA_JPEG_COMPRESSED) {
1922            return BitmapFactory.decodeByteArray(mThumbnailBytes, 0, mThumbnailLength);
1923        } else if (mThumbnailCompression == DATA_UNCOMPRESSED) {
1924            int[] rgbValues = new int[mThumbnailBytes.length / 3];
1925            byte alpha = (byte) 0xff000000;
1926            for (int i = 0; i < rgbValues.length; i++) {
1927                rgbValues[i] = alpha + (mThumbnailBytes[3 * i] << 16)
1928                        + (mThumbnailBytes[3 * i + 1] << 8) + mThumbnailBytes[3 * i + 2];
1929            }
1930
1931            ExifAttribute imageLengthAttribute =
1932                    (ExifAttribute) mAttributes[IFD_TYPE_THUMBNAIL].get(TAG_IMAGE_LENGTH);
1933            ExifAttribute imageWidthAttribute =
1934                    (ExifAttribute) mAttributes[IFD_TYPE_THUMBNAIL].get(TAG_IMAGE_WIDTH);
1935            if (imageLengthAttribute != null && imageWidthAttribute != null) {
1936                int imageLength = imageLengthAttribute.getIntValue(mExifByteOrder);
1937                int imageWidth = imageWidthAttribute.getIntValue(mExifByteOrder);
1938                return Bitmap.createBitmap(
1939                        rgbValues, imageWidth, imageLength, Bitmap.Config.ARGB_8888);
1940            }
1941        }
1942        return null;
1943    }
1944
1945    /**
1946     * Returns true if thumbnail image is JPEG Compressed, or false if either thumbnail image does
1947     * not exist or thumbnail image is uncompressed.
1948     */
1949    public boolean isThumbnailCompressed() {
1950        if (!mHasThumbnail) {
1951            return false;
1952        }
1953        if (mThumbnailCompression == DATA_JPEG || mThumbnailCompression == DATA_JPEG_COMPRESSED) {
1954            return true;
1955        }
1956        return false;
1957    }
1958
1959    /**
1960     * Returns the offset and length of thumbnail inside the image file, or
1961     * {@code null} if there is no thumbnail.
1962     *
1963     * @return two-element array, the offset in the first value, and length in
1964     *         the second, or {@code null} if no thumbnail was found.
1965     */
1966    public long[] getThumbnailRange() {
1967        if (!mHasThumbnail) {
1968            return null;
1969        }
1970
1971        long[] range = new long[2];
1972        range[0] = mThumbnailOffset;
1973        range[1] = mThumbnailLength;
1974
1975        return range;
1976    }
1977
1978    /**
1979     * Stores the latitude and longitude value in a float array. The first element is
1980     * the latitude, and the second element is the longitude. Returns false if the
1981     * Exif tags are not available.
1982     */
1983    public boolean getLatLong(float output[]) {
1984        String latValue = getAttribute(TAG_GPS_LATITUDE);
1985        String latRef = getAttribute(TAG_GPS_LATITUDE_REF);
1986        String lngValue = getAttribute(TAG_GPS_LONGITUDE);
1987        String lngRef = getAttribute(TAG_GPS_LONGITUDE_REF);
1988
1989        if (latValue != null && latRef != null && lngValue != null && lngRef != null) {
1990            try {
1991                output[0] = convertRationalLatLonToFloat(latValue, latRef);
1992                output[1] = convertRationalLatLonToFloat(lngValue, lngRef);
1993                return true;
1994            } catch (IllegalArgumentException e) {
1995                // if values are not parseable
1996            }
1997        }
1998
1999        return false;
2000    }
2001
2002    /**
2003     * Return the altitude in meters. If the exif tag does not exist, return
2004     * <var>defaultValue</var>.
2005     *
2006     * @param defaultValue the value to return if the tag is not available.
2007     */
2008    public double getAltitude(double defaultValue) {
2009        double altitude = getAttributeDouble(TAG_GPS_ALTITUDE, -1);
2010        int ref = getAttributeInt(TAG_GPS_ALTITUDE_REF, -1);
2011
2012        if (altitude >= 0 && ref >= 0) {
2013            return (altitude * ((ref == 1) ? -1 : 1));
2014        } else {
2015            return defaultValue;
2016        }
2017    }
2018
2019    /**
2020     * Returns number of milliseconds since Jan. 1, 1970, midnight local time.
2021     * Returns -1 if the date time information if not available.
2022     * @hide
2023     */
2024    public long getDateTime() {
2025        String dateTimeString = getAttribute(TAG_DATETIME);
2026        if (dateTimeString == null
2027                || !sNonZeroTimePattern.matcher(dateTimeString).matches()) return -1;
2028
2029        ParsePosition pos = new ParsePosition(0);
2030        try {
2031            // The exif field is in local time. Parsing it as if it is UTC will yield time
2032            // since 1/1/1970 local time
2033            Date datetime = sFormatter.parse(dateTimeString, pos);
2034            if (datetime == null) return -1;
2035            long msecs = datetime.getTime();
2036
2037            String subSecs = getAttribute(TAG_SUBSEC_TIME);
2038            if (subSecs != null) {
2039                try {
2040                    long sub = Long.parseLong(subSecs);
2041                    while (sub > 1000) {
2042                        sub /= 10;
2043                    }
2044                    msecs += sub;
2045                } catch (NumberFormatException e) {
2046                    // Ignored
2047                }
2048            }
2049            return msecs;
2050        } catch (IllegalArgumentException e) {
2051            return -1;
2052        }
2053    }
2054
2055    /**
2056     * Returns number of milliseconds since Jan. 1, 1970, midnight UTC.
2057     * Returns -1 if the date time information if not available.
2058     * @hide
2059     */
2060    public long getGpsDateTime() {
2061        String date = getAttribute(TAG_GPS_DATESTAMP);
2062        String time = getAttribute(TAG_GPS_TIMESTAMP);
2063        if (date == null || time == null
2064                || (!sNonZeroTimePattern.matcher(date).matches()
2065                && !sNonZeroTimePattern.matcher(time).matches())) {
2066            return -1;
2067        }
2068
2069        String dateTimeString = date + ' ' + time;
2070
2071        ParsePosition pos = new ParsePosition(0);
2072        try {
2073            Date datetime = sFormatter.parse(dateTimeString, pos);
2074            if (datetime == null) return -1;
2075            return datetime.getTime();
2076        } catch (IllegalArgumentException e) {
2077            return -1;
2078        }
2079    }
2080
2081    private static float convertRationalLatLonToFloat(String rationalString, String ref) {
2082        try {
2083            String [] parts = rationalString.split(",");
2084
2085            String [] pair;
2086            pair = parts[0].split("/");
2087            double degrees = Double.parseDouble(pair[0].trim())
2088                    / Double.parseDouble(pair[1].trim());
2089
2090            pair = parts[1].split("/");
2091            double minutes = Double.parseDouble(pair[0].trim())
2092                    / Double.parseDouble(pair[1].trim());
2093
2094            pair = parts[2].split("/");
2095            double seconds = Double.parseDouble(pair[0].trim())
2096                    / Double.parseDouble(pair[1].trim());
2097
2098            double result = degrees + (minutes / 60.0) + (seconds / 3600.0);
2099            if ((ref.equals("S") || ref.equals("W"))) {
2100                return (float) -result;
2101            }
2102            return (float) result;
2103        } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
2104            // Not valid
2105            throw new IllegalArgumentException();
2106        }
2107    }
2108
2109    // Checks the type of image file
2110    private int getMimeType(BufferedInputStream in) throws IOException {
2111        in.mark(SIGNATURE_CHECK_SIZE);
2112        byte[] signatureCheckBytes = new byte[SIGNATURE_CHECK_SIZE];
2113        in.read(signatureCheckBytes);
2114        in.reset();
2115        if (isJpegFormat(signatureCheckBytes)) {
2116            return IMAGE_TYPE_JPEG;
2117        } else if (isRafFormat(signatureCheckBytes)) {
2118            return IMAGE_TYPE_RAF;
2119        } else if (isHeifFormat(signatureCheckBytes)) {
2120            return IMAGE_TYPE_HEIF;
2121        } else if (isOrfFormat(signatureCheckBytes)) {
2122            return IMAGE_TYPE_ORF;
2123        } else if (isRw2Format(signatureCheckBytes)) {
2124            return IMAGE_TYPE_RW2;
2125        }
2126        // Certain file formats (PEF) are identified in readImageFileDirectory()
2127        return IMAGE_TYPE_UNKNOWN;
2128    }
2129
2130    /**
2131     * This method looks at the first 3 bytes to determine if this file is a JPEG file.
2132     * See http://www.media.mit.edu/pia/Research/deepview/exif.html, "JPEG format and Marker"
2133     */
2134    private static boolean isJpegFormat(byte[] signatureCheckBytes) throws IOException {
2135        for (int i = 0; i < JPEG_SIGNATURE.length; i++) {
2136            if (signatureCheckBytes[i] != JPEG_SIGNATURE[i]) {
2137                return false;
2138            }
2139        }
2140        return true;
2141    }
2142
2143    /**
2144     * This method looks at the first 15 bytes to determine if this file is a RAF file.
2145     * There is no official specification for RAF files from Fuji, but there is an online archive of
2146     * image file specifications:
2147     * http://fileformats.archiveteam.org/wiki/Fujifilm_RAF
2148     */
2149    private boolean isRafFormat(byte[] signatureCheckBytes) throws IOException {
2150        byte[] rafSignatureBytes = RAF_SIGNATURE.getBytes();
2151        for (int i = 0; i < rafSignatureBytes.length; i++) {
2152            if (signatureCheckBytes[i] != rafSignatureBytes[i]) {
2153                return false;
2154            }
2155        }
2156        return true;
2157    }
2158
2159    private boolean isHeifFormat(byte[] signatureCheckBytes) throws IOException {
2160        ByteOrderedDataInputStream signatureInputStream = null;
2161        try {
2162            signatureInputStream = new ByteOrderedDataInputStream(signatureCheckBytes);
2163            signatureInputStream.setByteOrder(ByteOrder.BIG_ENDIAN);
2164
2165            long chunkSize = signatureInputStream.readInt();
2166            byte[] chunkType = new byte[4];
2167            signatureInputStream.read(chunkType);
2168
2169            if (!Arrays.equals(chunkType, HEIF_TYPE_FTYP)) {
2170                return false;
2171            }
2172
2173            long chunkDataOffset = 8;
2174            if (chunkSize == 1) {
2175                // This indicates that the next 8 bytes represent the chunk size,
2176                // and chunk data comes after that.
2177                chunkSize = signatureInputStream.readLong();
2178                if (chunkSize < 16) {
2179                    // The smallest valid chunk is 16 bytes long in this case.
2180                    return false;
2181                }
2182                chunkDataOffset += 8;
2183            }
2184
2185            // only sniff up to signatureCheckBytes.length
2186            if (chunkSize > signatureCheckBytes.length) {
2187                chunkSize = signatureCheckBytes.length;
2188            }
2189
2190            long chunkDataSize = chunkSize - chunkDataOffset;
2191
2192            // It should at least have major brand (4-byte) and minor version (4-byte).
2193            // The rest of the chunk (if any) is a list of (4-byte) compatible brands.
2194            if (chunkDataSize < 8) {
2195                return false;
2196            }
2197
2198            byte[] brand = new byte[4];
2199            boolean isMif1 = false;
2200            boolean isHeic = false;
2201            for (long i = 0; i < chunkDataSize / 4;  ++i) {
2202                if (signatureInputStream.read(brand) != brand.length) {
2203                    return false;
2204                }
2205                if (i == 1) {
2206                    // Skip this index, it refers to the minorVersion, not a brand.
2207                    continue;
2208                }
2209                if (Arrays.equals(brand, HEIF_BRAND_MIF1)) {
2210                    isMif1 = true;
2211                } else if (Arrays.equals(brand, HEIF_BRAND_HEIC)) {
2212                    isHeic = true;
2213                }
2214                if (isMif1 && isHeic) {
2215                    return true;
2216                }
2217            }
2218        } catch (Exception e) {
2219            if (DEBUG) {
2220                Log.d(TAG, "Exception parsing HEIF file type box.", e);
2221            }
2222        } finally {
2223            if (signatureInputStream != null) {
2224                signatureInputStream.close();
2225                signatureInputStream = null;
2226            }
2227        }
2228        return false;
2229    }
2230
2231    /**
2232     * ORF has a similar structure to TIFF but it contains a different signature at the TIFF Header.
2233     * This method looks at the 2 bytes following the Byte Order bytes to determine if this file is
2234     * an ORF file.
2235     * There is no official specification for ORF files from Olympus, but there is an online archive
2236     * of image file specifications:
2237     * http://fileformats.archiveteam.org/wiki/Olympus_ORF
2238     */
2239    private boolean isOrfFormat(byte[] signatureCheckBytes) throws IOException {
2240        ByteOrderedDataInputStream signatureInputStream =
2241                new ByteOrderedDataInputStream(signatureCheckBytes);
2242        // Read byte order
2243        mExifByteOrder = readByteOrder(signatureInputStream);
2244        // Set byte order
2245        signatureInputStream.setByteOrder(mExifByteOrder);
2246
2247        short orfSignature = signatureInputStream.readShort();
2248        if (orfSignature == ORF_SIGNATURE_1 || orfSignature == ORF_SIGNATURE_2) {
2249            return true;
2250        }
2251        return false;
2252    }
2253
2254    /**
2255     * RW2 is TIFF-based, but stores 0x55 signature byte instead of 0x42 at the header
2256     * See http://lclevy.free.fr/raw/
2257     */
2258    private boolean isRw2Format(byte[] signatureCheckBytes) throws IOException {
2259        ByteOrderedDataInputStream signatureInputStream =
2260                new ByteOrderedDataInputStream(signatureCheckBytes);
2261        // Read byte order
2262        mExifByteOrder = readByteOrder(signatureInputStream);
2263        // Set byte order
2264        signatureInputStream.setByteOrder(mExifByteOrder);
2265
2266        short signatureByte = signatureInputStream.readShort();
2267        if (signatureByte == RW2_SIGNATURE) {
2268            return true;
2269        }
2270        return false;
2271    }
2272
2273    /**
2274     * Loads EXIF attributes from a JPEG input stream.
2275     *
2276     * @param in The input stream that starts with the JPEG data.
2277     * @param jpegOffset The offset value in input stream for JPEG data.
2278     * @param imageType The image type from which to retrieve metadata. Use IFD_TYPE_PRIMARY for
2279     *                   primary image, IFD_TYPE_PREVIEW for preview image, and
2280     *                   IFD_TYPE_THUMBNAIL for thumbnail image.
2281     * @throws IOException If the data contains invalid JPEG markers, offsets, or length values.
2282     */
2283    private void getJpegAttributes(ByteOrderedDataInputStream in, int jpegOffset, int imageType)
2284            throws IOException {
2285        // See JPEG File Interchange Format Specification, "JFIF Specification"
2286        if (DEBUG) {
2287            Log.d(TAG, "getJpegAttributes starting with: " + in);
2288        }
2289
2290        // JPEG uses Big Endian by default. See https://people.cs.umass.edu/~verts/cs32/endian.html
2291        in.setByteOrder(ByteOrder.BIG_ENDIAN);
2292
2293        // Skip to JPEG data
2294        in.seek(jpegOffset);
2295        int bytesRead = jpegOffset;
2296
2297        byte marker;
2298        if ((marker = in.readByte()) != MARKER) {
2299            throw new IOException("Invalid marker: " + Integer.toHexString(marker & 0xff));
2300        }
2301        ++bytesRead;
2302        if (in.readByte() != MARKER_SOI) {
2303            throw new IOException("Invalid marker: " + Integer.toHexString(marker & 0xff));
2304        }
2305        ++bytesRead;
2306        while (true) {
2307            marker = in.readByte();
2308            if (marker != MARKER) {
2309                throw new IOException("Invalid marker:" + Integer.toHexString(marker & 0xff));
2310            }
2311            ++bytesRead;
2312            marker = in.readByte();
2313            if (DEBUG) {
2314                Log.d(TAG, "Found JPEG segment indicator: " + Integer.toHexString(marker & 0xff));
2315            }
2316            ++bytesRead;
2317
2318            // EOI indicates the end of an image and in case of SOS, JPEG image stream starts and
2319            // the image data will terminate right after.
2320            if (marker == MARKER_EOI || marker == MARKER_SOS) {
2321                break;
2322            }
2323            int length = in.readUnsignedShort() - 2;
2324            bytesRead += 2;
2325            if (DEBUG) {
2326                Log.d(TAG, "JPEG segment: " + Integer.toHexString(marker & 0xff) + " (length: "
2327                        + (length + 2) + ")");
2328            }
2329            if (length < 0) {
2330                throw new IOException("Invalid length");
2331            }
2332            switch (marker) {
2333                case MARKER_APP1: {
2334                    if (DEBUG) {
2335                        Log.d(TAG, "MARKER_APP1");
2336                    }
2337                    if (length < 6) {
2338                        // Skip if it's not an EXIF APP1 segment.
2339                        break;
2340                    }
2341                    byte[] identifier = new byte[6];
2342                    if (in.read(identifier) != 6) {
2343                        throw new IOException("Invalid exif");
2344                    }
2345                    bytesRead += 6;
2346                    length -= 6;
2347                    if (!Arrays.equals(identifier, IDENTIFIER_EXIF_APP1)) {
2348                        // Skip if it's not an EXIF APP1 segment.
2349                        break;
2350                    }
2351                    if (length <= 0) {
2352                        throw new IOException("Invalid exif");
2353                    }
2354                    if (DEBUG) {
2355                        Log.d(TAG, "readExifSegment with a byte array (length: " + length + ")");
2356                    }
2357                    // Save offset values for createJpegThumbnailBitmap() function
2358                    mExifOffset = bytesRead;
2359
2360                    byte[] bytes = new byte[length];
2361                    if (in.read(bytes) != length) {
2362                        throw new IOException("Invalid exif");
2363                    }
2364                    bytesRead += length;
2365                    length = 0;
2366
2367                    readExifSegment(bytes, imageType);
2368                    break;
2369                }
2370
2371                case MARKER_COM: {
2372                    byte[] bytes = new byte[length];
2373                    if (in.read(bytes) != length) {
2374                        throw new IOException("Invalid exif");
2375                    }
2376                    length = 0;
2377                    if (getAttribute(TAG_USER_COMMENT) == null) {
2378                        mAttributes[IFD_TYPE_EXIF].put(TAG_USER_COMMENT, ExifAttribute.createString(
2379                                new String(bytes, ASCII)));
2380                    }
2381                    break;
2382                }
2383
2384                case MARKER_SOF0:
2385                case MARKER_SOF1:
2386                case MARKER_SOF2:
2387                case MARKER_SOF3:
2388                case MARKER_SOF5:
2389                case MARKER_SOF6:
2390                case MARKER_SOF7:
2391                case MARKER_SOF9:
2392                case MARKER_SOF10:
2393                case MARKER_SOF11:
2394                case MARKER_SOF13:
2395                case MARKER_SOF14:
2396                case MARKER_SOF15: {
2397                    if (in.skipBytes(1) != 1) {
2398                        throw new IOException("Invalid SOFx");
2399                    }
2400                    mAttributes[imageType].put(TAG_IMAGE_LENGTH, ExifAttribute.createULong(
2401                            in.readUnsignedShort(), mExifByteOrder));
2402                    mAttributes[imageType].put(TAG_IMAGE_WIDTH, ExifAttribute.createULong(
2403                            in.readUnsignedShort(), mExifByteOrder));
2404                    length -= 5;
2405                    break;
2406                }
2407
2408                default: {
2409                    break;
2410                }
2411            }
2412            if (length < 0) {
2413                throw new IOException("Invalid length");
2414            }
2415            if (in.skipBytes(length) != length) {
2416                throw new IOException("Invalid JPEG segment");
2417            }
2418            bytesRead += length;
2419        }
2420        // Restore original byte order
2421        in.setByteOrder(mExifByteOrder);
2422    }
2423
2424    private void getRawAttributes(ByteOrderedDataInputStream in) throws IOException {
2425        // Parse TIFF Headers. See JEITA CP-3451C Section 4.5.2. Table 1.
2426        parseTiffHeaders(in, in.available());
2427
2428        // Read TIFF image file directories. See JEITA CP-3451C Section 4.5.2. Figure 6.
2429        readImageFileDirectory(in, IFD_TYPE_PRIMARY);
2430
2431        // Update ImageLength/Width tags for all image data.
2432        updateImageSizeValues(in, IFD_TYPE_PRIMARY);
2433        updateImageSizeValues(in, IFD_TYPE_PREVIEW);
2434        updateImageSizeValues(in, IFD_TYPE_THUMBNAIL);
2435
2436        // Check if each image data is in valid position.
2437        validateImages(in);
2438
2439        if (mMimeType == IMAGE_TYPE_PEF) {
2440            // PEF files contain a MakerNote data, which contains the data for ColorSpace tag.
2441            // See http://lclevy.free.fr/raw/ and piex.cc PefGetPreviewData()
2442            ExifAttribute makerNoteAttribute =
2443                    (ExifAttribute) mAttributes[IFD_TYPE_EXIF].get(TAG_MAKER_NOTE);
2444            if (makerNoteAttribute != null) {
2445                // Create an ordered DataInputStream for MakerNote
2446                ByteOrderedDataInputStream makerNoteDataInputStream =
2447                        new ByteOrderedDataInputStream(makerNoteAttribute.bytes);
2448                makerNoteDataInputStream.setByteOrder(mExifByteOrder);
2449
2450                // Seek to MakerNote data
2451                makerNoteDataInputStream.seek(PEF_MAKER_NOTE_SKIP_SIZE);
2452
2453                // Read IFD data from MakerNote
2454                readImageFileDirectory(makerNoteDataInputStream, IFD_TYPE_PEF);
2455
2456                // Update ColorSpace tag
2457                ExifAttribute colorSpaceAttribute =
2458                        (ExifAttribute) mAttributes[IFD_TYPE_PEF].get(TAG_COLOR_SPACE);
2459                if (colorSpaceAttribute != null) {
2460                    mAttributes[IFD_TYPE_EXIF].put(TAG_COLOR_SPACE, colorSpaceAttribute);
2461                }
2462            }
2463        }
2464    }
2465
2466    /**
2467     * RAF files contains a JPEG and a CFA data.
2468     * The JPEG contains two images, a preview and a thumbnail, while the CFA contains a RAW image.
2469     * This method looks at the first 160 bytes of a RAF file to retrieve the offset and length
2470     * values for the JPEG and CFA data.
2471     * Using that data, it parses the JPEG data to retrieve the preview and thumbnail image data,
2472     * then parses the CFA metadata to retrieve the primary image length/width values.
2473     * For data format details, see http://fileformats.archiveteam.org/wiki/Fujifilm_RAF
2474     */
2475    private void getRafAttributes(ByteOrderedDataInputStream in) throws IOException {
2476        // Retrieve offset & length values
2477        in.skipBytes(RAF_OFFSET_TO_JPEG_IMAGE_OFFSET);
2478        byte[] jpegOffsetBytes = new byte[4];
2479        byte[] cfaHeaderOffsetBytes = new byte[4];
2480        in.read(jpegOffsetBytes);
2481        // Skip JPEG length value since it is not needed
2482        in.skipBytes(RAF_JPEG_LENGTH_VALUE_SIZE);
2483        in.read(cfaHeaderOffsetBytes);
2484        int rafJpegOffset = ByteBuffer.wrap(jpegOffsetBytes).getInt();
2485        int rafCfaHeaderOffset = ByteBuffer.wrap(cfaHeaderOffsetBytes).getInt();
2486
2487        // Retrieve JPEG image metadata
2488        getJpegAttributes(in, rafJpegOffset, IFD_TYPE_PREVIEW);
2489
2490        // Skip to CFA header offset.
2491        in.seek(rafCfaHeaderOffset);
2492
2493        // Retrieve primary image length/width values, if TAG_RAF_IMAGE_SIZE exists
2494        in.setByteOrder(ByteOrder.BIG_ENDIAN);
2495        int numberOfDirectoryEntry = in.readInt();
2496        if (DEBUG) {
2497            Log.d(TAG, "numberOfDirectoryEntry: " + numberOfDirectoryEntry);
2498        }
2499        // CFA stores some metadata about the RAW image. Since CFA uses proprietary tags, can only
2500        // find and retrieve image size information tags, while skipping others.
2501        // See piex.cc RafGetDimension()
2502        for (int i = 0; i < numberOfDirectoryEntry; ++i) {
2503            int tagNumber = in.readUnsignedShort();
2504            int numberOfBytes = in.readUnsignedShort();
2505            if (tagNumber == TAG_RAF_IMAGE_SIZE.number) {
2506                int imageLength = in.readShort();
2507                int imageWidth = in.readShort();
2508                ExifAttribute imageLengthAttribute =
2509                        ExifAttribute.createUShort(imageLength, mExifByteOrder);
2510                ExifAttribute imageWidthAttribute =
2511                        ExifAttribute.createUShort(imageWidth, mExifByteOrder);
2512                mAttributes[IFD_TYPE_PRIMARY].put(TAG_IMAGE_LENGTH, imageLengthAttribute);
2513                mAttributes[IFD_TYPE_PRIMARY].put(TAG_IMAGE_WIDTH, imageWidthAttribute);
2514                if (DEBUG) {
2515                    Log.d(TAG, "Updated to length: " + imageLength + ", width: " + imageWidth);
2516                }
2517                return;
2518            }
2519            in.skipBytes(numberOfBytes);
2520        }
2521    }
2522
2523    private void getHeifAttributes(ByteOrderedDataInputStream in) throws IOException {
2524        MediaMetadataRetriever retriever = new MediaMetadataRetriever();
2525        try {
2526            if (mSeekableFileDescriptor != null) {
2527                retriever.setDataSource(mSeekableFileDescriptor);
2528            } else {
2529                retriever.setDataSource(new MediaDataSource() {
2530                    long mPosition;
2531
2532                    @Override
2533                    public void close() throws IOException {}
2534
2535                    @Override
2536                    public int readAt(long position, byte[] buffer, int offset, int size)
2537                            throws IOException {
2538                        if (size == 0) {
2539                            return 0;
2540                        }
2541                        if (position < 0) {
2542                            return -1;
2543                        }
2544                        if (mPosition != position) {
2545                            in.seek(position);
2546                            mPosition = position;
2547                        }
2548
2549                        int bytesRead = in.read(buffer, offset, size);
2550                        if (bytesRead < 0) {
2551                            mPosition = -1; // need to seek on next read
2552                            return -1;
2553                        }
2554
2555                        mPosition += bytesRead;
2556                        return bytesRead;
2557                    }
2558
2559                    @Override
2560                    public long getSize() throws IOException {
2561                        return -1;
2562                    }
2563                });
2564            }
2565
2566            String hasVideo = retriever.extractMetadata(
2567                    MediaMetadataRetriever.METADATA_KEY_HAS_VIDEO);
2568
2569            final String METADATA_HAS_VIDEO_VALUE_YES = "yes";
2570            if (METADATA_HAS_VIDEO_VALUE_YES.equals(hasVideo)) {
2571                String width = retriever.extractMetadata(
2572                        MediaMetadataRetriever.METADATA_KEY_VIDEO_WIDTH);
2573                String height = retriever.extractMetadata(
2574                        MediaMetadataRetriever.METADATA_KEY_VIDEO_HEIGHT);
2575
2576                if (width != null) {
2577                    mAttributes[IFD_TYPE_PRIMARY].put(TAG_IMAGE_WIDTH,
2578                            ExifAttribute.createUShort(Integer.parseInt(width), mExifByteOrder));
2579                }
2580
2581                if (height != null) {
2582                    mAttributes[IFD_TYPE_PRIMARY].put(TAG_IMAGE_LENGTH,
2583                            ExifAttribute.createUShort(Integer.parseInt(height), mExifByteOrder));
2584                }
2585
2586                String rotation = retriever.extractMetadata(
2587                        MediaMetadataRetriever.METADATA_KEY_VIDEO_ROTATION);
2588                if (rotation != null) {
2589                    int orientation = ExifInterface.ORIENTATION_NORMAL;
2590
2591                    // all rotation angles in CW
2592                    switch (Integer.parseInt(rotation)) {
2593                        case 90:
2594                            orientation = ExifInterface.ORIENTATION_ROTATE_90;
2595                            break;
2596                        case 180:
2597                            orientation = ExifInterface.ORIENTATION_ROTATE_180;
2598                            break;
2599                        case 270:
2600                            orientation = ExifInterface.ORIENTATION_ROTATE_270;
2601                            break;
2602                    }
2603
2604                    mAttributes[IFD_TYPE_PRIMARY].put(TAG_ORIENTATION,
2605                            ExifAttribute.createUShort(orientation, mExifByteOrder));
2606                }
2607
2608                if (DEBUG) {
2609                    Log.d(TAG, "Heif meta: " + width + "x" + height + ", rotation " + rotation);
2610                }
2611            }
2612        } finally {
2613            retriever.release();
2614        }
2615    }
2616
2617    /**
2618     * ORF files contains a primary image data and a MakerNote data that contains preview/thumbnail
2619     * images. Both data takes the form of IFDs and can therefore be read with the
2620     * readImageFileDirectory() method.
2621     * This method reads all the necessary data and updates the primary/preview/thumbnail image
2622     * information according to the GetOlympusPreviewImage() method in piex.cc.
2623     * For data format details, see the following:
2624     * http://fileformats.archiveteam.org/wiki/Olympus_ORF
2625     * https://libopenraw.freedesktop.org/wiki/Olympus_ORF
2626     */
2627    private void getOrfAttributes(ByteOrderedDataInputStream in) throws IOException {
2628        // Retrieve primary image data
2629        // Other Exif data will be located in the Makernote.
2630        getRawAttributes(in);
2631
2632        // Additionally retrieve preview/thumbnail information from MakerNote tag, which contains
2633        // proprietary tags and therefore does not have offical documentation
2634        // See GetOlympusPreviewImage() in piex.cc & http://www.exiv2.org/tags-olympus.html
2635        ExifAttribute makerNoteAttribute =
2636                (ExifAttribute) mAttributes[IFD_TYPE_EXIF].get(TAG_MAKER_NOTE);
2637        if (makerNoteAttribute != null) {
2638            // Create an ordered DataInputStream for MakerNote
2639            ByteOrderedDataInputStream makerNoteDataInputStream =
2640                    new ByteOrderedDataInputStream(makerNoteAttribute.bytes);
2641            makerNoteDataInputStream.setByteOrder(mExifByteOrder);
2642
2643            // There are two types of headers for Olympus MakerNotes
2644            // See http://www.exiv2.org/makernote.html#R1
2645            byte[] makerNoteHeader1Bytes = new byte[ORF_MAKER_NOTE_HEADER_1.length];
2646            makerNoteDataInputStream.readFully(makerNoteHeader1Bytes);
2647            makerNoteDataInputStream.seek(0);
2648            byte[] makerNoteHeader2Bytes = new byte[ORF_MAKER_NOTE_HEADER_2.length];
2649            makerNoteDataInputStream.readFully(makerNoteHeader2Bytes);
2650            // Skip the corresponding amount of bytes for each header type
2651            if (Arrays.equals(makerNoteHeader1Bytes, ORF_MAKER_NOTE_HEADER_1)) {
2652                makerNoteDataInputStream.seek(ORF_MAKER_NOTE_HEADER_1_SIZE);
2653            } else if (Arrays.equals(makerNoteHeader2Bytes, ORF_MAKER_NOTE_HEADER_2)) {
2654                makerNoteDataInputStream.seek(ORF_MAKER_NOTE_HEADER_2_SIZE);
2655            }
2656
2657            // Read IFD data from MakerNote
2658            readImageFileDirectory(makerNoteDataInputStream, IFD_TYPE_ORF_MAKER_NOTE);
2659
2660            // Retrieve & update preview image offset & length values
2661            ExifAttribute imageLengthAttribute = (ExifAttribute)
2662                    mAttributes[IFD_TYPE_ORF_CAMERA_SETTINGS].get(TAG_ORF_PREVIEW_IMAGE_START);
2663            ExifAttribute bitsPerSampleAttribute = (ExifAttribute)
2664                    mAttributes[IFD_TYPE_ORF_CAMERA_SETTINGS].get(TAG_ORF_PREVIEW_IMAGE_LENGTH);
2665
2666            if (imageLengthAttribute != null && bitsPerSampleAttribute != null) {
2667                mAttributes[IFD_TYPE_PREVIEW].put(TAG_JPEG_INTERCHANGE_FORMAT,
2668                        imageLengthAttribute);
2669                mAttributes[IFD_TYPE_PREVIEW].put(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH,
2670                        bitsPerSampleAttribute);
2671            }
2672
2673            // TODO: Check this behavior in other ORF files
2674            // Retrieve primary image length & width values
2675            // See piex.cc GetOlympusPreviewImage()
2676            ExifAttribute aspectFrameAttribute = (ExifAttribute)
2677                    mAttributes[IFD_TYPE_ORF_IMAGE_PROCESSING].get(TAG_ORF_ASPECT_FRAME);
2678            if (aspectFrameAttribute != null) {
2679                int[] aspectFrameValues = new int[4];
2680                aspectFrameValues = (int[]) aspectFrameAttribute.getValue(mExifByteOrder);
2681                if (aspectFrameValues[2] > aspectFrameValues[0] &&
2682                        aspectFrameValues[3] > aspectFrameValues[1]) {
2683                    int primaryImageWidth = aspectFrameValues[2] - aspectFrameValues[0] + 1;
2684                    int primaryImageLength = aspectFrameValues[3] - aspectFrameValues[1] + 1;
2685                    // Swap width & length values
2686                    if (primaryImageWidth < primaryImageLength) {
2687                        primaryImageWidth += primaryImageLength;
2688                        primaryImageLength = primaryImageWidth - primaryImageLength;
2689                        primaryImageWidth -= primaryImageLength;
2690                    }
2691                    ExifAttribute primaryImageWidthAttribute =
2692                            ExifAttribute.createUShort(primaryImageWidth, mExifByteOrder);
2693                    ExifAttribute primaryImageLengthAttribute =
2694                            ExifAttribute.createUShort(primaryImageLength, mExifByteOrder);
2695
2696                    mAttributes[IFD_TYPE_PRIMARY].put(TAG_IMAGE_WIDTH, primaryImageWidthAttribute);
2697                    mAttributes[IFD_TYPE_PRIMARY].put(TAG_IMAGE_LENGTH, primaryImageLengthAttribute);
2698                }
2699            }
2700        }
2701    }
2702
2703    // RW2 contains the primary image data in IFD0 and the preview and/or thumbnail image data in
2704    // the JpgFromRaw tag
2705    // See https://libopenraw.freedesktop.org/wiki/Panasonic_RAW/ and piex.cc Rw2GetPreviewData()
2706    private void getRw2Attributes(ByteOrderedDataInputStream in) throws IOException {
2707        // Retrieve primary image data
2708        getRawAttributes(in);
2709
2710        // Retrieve preview and/or thumbnail image data
2711        ExifAttribute jpgFromRawAttribute =
2712                (ExifAttribute) mAttributes[IFD_TYPE_PRIMARY].get(TAG_RW2_JPG_FROM_RAW);
2713        if (jpgFromRawAttribute != null) {
2714            getJpegAttributes(in, mRw2JpgFromRawOffset, IFD_TYPE_PREVIEW);
2715        }
2716
2717        // Set ISO tag value if necessary
2718        ExifAttribute rw2IsoAttribute =
2719                (ExifAttribute) mAttributes[IFD_TYPE_PRIMARY].get(TAG_RW2_ISO);
2720        ExifAttribute exifIsoAttribute =
2721                (ExifAttribute) mAttributes[IFD_TYPE_EXIF].get(TAG_ISO_SPEED_RATINGS);
2722        if (rw2IsoAttribute != null && exifIsoAttribute == null) {
2723            // Place this attribute only if it doesn't exist
2724            mAttributes[IFD_TYPE_EXIF].put(TAG_ISO_SPEED_RATINGS, rw2IsoAttribute);
2725        }
2726    }
2727
2728    // Stores a new JPEG image with EXIF attributes into a given output stream.
2729    private void saveJpegAttributes(InputStream inputStream, OutputStream outputStream)
2730            throws IOException {
2731        // See JPEG File Interchange Format Specification, "JFIF Specification"
2732        if (DEBUG) {
2733            Log.d(TAG, "saveJpegAttributes starting with (inputStream: " + inputStream
2734                    + ", outputStream: " + outputStream + ")");
2735        }
2736        DataInputStream dataInputStream = new DataInputStream(inputStream);
2737        ByteOrderedDataOutputStream dataOutputStream =
2738                new ByteOrderedDataOutputStream(outputStream, ByteOrder.BIG_ENDIAN);
2739        if (dataInputStream.readByte() != MARKER) {
2740            throw new IOException("Invalid marker");
2741        }
2742        dataOutputStream.writeByte(MARKER);
2743        if (dataInputStream.readByte() != MARKER_SOI) {
2744            throw new IOException("Invalid marker");
2745        }
2746        dataOutputStream.writeByte(MARKER_SOI);
2747
2748        // Write EXIF APP1 segment
2749        dataOutputStream.writeByte(MARKER);
2750        dataOutputStream.writeByte(MARKER_APP1);
2751        writeExifSegment(dataOutputStream, 6);
2752
2753        byte[] bytes = new byte[4096];
2754
2755        while (true) {
2756            byte marker = dataInputStream.readByte();
2757            if (marker != MARKER) {
2758                throw new IOException("Invalid marker");
2759            }
2760            marker = dataInputStream.readByte();
2761            switch (marker) {
2762                case MARKER_APP1: {
2763                    int length = dataInputStream.readUnsignedShort() - 2;
2764                    if (length < 0) {
2765                        throw new IOException("Invalid length");
2766                    }
2767                    byte[] identifier = new byte[6];
2768                    if (length >= 6) {
2769                        if (dataInputStream.read(identifier) != 6) {
2770                            throw new IOException("Invalid exif");
2771                        }
2772                        if (Arrays.equals(identifier, IDENTIFIER_EXIF_APP1)) {
2773                            // Skip the original EXIF APP1 segment.
2774                            if (dataInputStream.skipBytes(length - 6) != length - 6) {
2775                                throw new IOException("Invalid length");
2776                            }
2777                            break;
2778                        }
2779                    }
2780                    // Copy non-EXIF APP1 segment.
2781                    dataOutputStream.writeByte(MARKER);
2782                    dataOutputStream.writeByte(marker);
2783                    dataOutputStream.writeUnsignedShort(length + 2);
2784                    if (length >= 6) {
2785                        length -= 6;
2786                        dataOutputStream.write(identifier);
2787                    }
2788                    int read;
2789                    while (length > 0 && (read = dataInputStream.read(
2790                            bytes, 0, Math.min(length, bytes.length))) >= 0) {
2791                        dataOutputStream.write(bytes, 0, read);
2792                        length -= read;
2793                    }
2794                    break;
2795                }
2796                case MARKER_EOI:
2797                case MARKER_SOS: {
2798                    dataOutputStream.writeByte(MARKER);
2799                    dataOutputStream.writeByte(marker);
2800                    // Copy all the remaining data
2801                    Streams.copy(dataInputStream, dataOutputStream);
2802                    return;
2803                }
2804                default: {
2805                    // Copy JPEG segment
2806                    dataOutputStream.writeByte(MARKER);
2807                    dataOutputStream.writeByte(marker);
2808                    int length = dataInputStream.readUnsignedShort();
2809                    dataOutputStream.writeUnsignedShort(length);
2810                    length -= 2;
2811                    if (length < 0) {
2812                        throw new IOException("Invalid length");
2813                    }
2814                    int read;
2815                    while (length > 0 && (read = dataInputStream.read(
2816                            bytes, 0, Math.min(length, bytes.length))) >= 0) {
2817                        dataOutputStream.write(bytes, 0, read);
2818                        length -= read;
2819                    }
2820                    break;
2821                }
2822            }
2823        }
2824    }
2825
2826    // Reads the given EXIF byte area and save its tag data into attributes.
2827    private void readExifSegment(byte[] exifBytes, int imageType) throws IOException {
2828        ByteOrderedDataInputStream dataInputStream =
2829                new ByteOrderedDataInputStream(exifBytes);
2830
2831        // Parse TIFF Headers. See JEITA CP-3451C Section 4.5.2. Table 1.
2832        parseTiffHeaders(dataInputStream, exifBytes.length);
2833
2834        // Read TIFF image file directories. See JEITA CP-3451C Section 4.5.2. Figure 6.
2835        readImageFileDirectory(dataInputStream, imageType);
2836    }
2837
2838    private void addDefaultValuesForCompatibility() {
2839        // If DATETIME tag has no value, then set the value to DATETIME_ORIGINAL tag's.
2840        String valueOfDateTimeOriginal = getAttribute(TAG_DATETIME_ORIGINAL);
2841        if (valueOfDateTimeOriginal != null && getAttribute(TAG_DATETIME) == null) {
2842            mAttributes[IFD_TYPE_PRIMARY].put(TAG_DATETIME,
2843                    ExifAttribute.createString(valueOfDateTimeOriginal));
2844        }
2845
2846        // Add the default value.
2847        if (getAttribute(TAG_IMAGE_WIDTH) == null) {
2848            mAttributes[IFD_TYPE_PRIMARY].put(TAG_IMAGE_WIDTH,
2849                    ExifAttribute.createULong(0, mExifByteOrder));
2850        }
2851        if (getAttribute(TAG_IMAGE_LENGTH) == null) {
2852            mAttributes[IFD_TYPE_PRIMARY].put(TAG_IMAGE_LENGTH,
2853                    ExifAttribute.createULong(0, mExifByteOrder));
2854        }
2855        if (getAttribute(TAG_ORIENTATION) == null) {
2856            mAttributes[IFD_TYPE_PRIMARY].put(TAG_ORIENTATION,
2857                    ExifAttribute.createUShort(0, mExifByteOrder));
2858        }
2859        if (getAttribute(TAG_LIGHT_SOURCE) == null) {
2860            mAttributes[IFD_TYPE_EXIF].put(TAG_LIGHT_SOURCE,
2861                    ExifAttribute.createULong(0, mExifByteOrder));
2862        }
2863    }
2864
2865    private ByteOrder readByteOrder(ByteOrderedDataInputStream dataInputStream)
2866            throws IOException {
2867        // Read byte order.
2868        short byteOrder = dataInputStream.readShort();
2869        switch (byteOrder) {
2870            case BYTE_ALIGN_II:
2871                if (DEBUG) {
2872                    Log.d(TAG, "readExifSegment: Byte Align II");
2873                }
2874                return ByteOrder.LITTLE_ENDIAN;
2875            case BYTE_ALIGN_MM:
2876                if (DEBUG) {
2877                    Log.d(TAG, "readExifSegment: Byte Align MM");
2878                }
2879                return ByteOrder.BIG_ENDIAN;
2880            default:
2881                throw new IOException("Invalid byte order: " + Integer.toHexString(byteOrder));
2882        }
2883    }
2884
2885    private void parseTiffHeaders(ByteOrderedDataInputStream dataInputStream,
2886            int exifBytesLength) throws IOException {
2887        // Read byte order
2888        mExifByteOrder = readByteOrder(dataInputStream);
2889        // Set byte order
2890        dataInputStream.setByteOrder(mExifByteOrder);
2891
2892        // Check start code
2893        int startCode = dataInputStream.readUnsignedShort();
2894        if (mMimeType != IMAGE_TYPE_ORF && mMimeType != IMAGE_TYPE_RW2 && startCode != START_CODE) {
2895            throw new IOException("Invalid start code: " + Integer.toHexString(startCode));
2896        }
2897
2898        // Read and skip to first ifd offset
2899        int firstIfdOffset = dataInputStream.readInt();
2900        if (firstIfdOffset < 8 || firstIfdOffset >= exifBytesLength) {
2901            throw new IOException("Invalid first Ifd offset: " + firstIfdOffset);
2902        }
2903        firstIfdOffset -= 8;
2904        if (firstIfdOffset > 0) {
2905            if (dataInputStream.skipBytes(firstIfdOffset) != firstIfdOffset) {
2906                throw new IOException("Couldn't jump to first Ifd: " + firstIfdOffset);
2907            }
2908        }
2909    }
2910
2911    // Reads image file directory, which is a tag group in EXIF.
2912    private void readImageFileDirectory(ByteOrderedDataInputStream dataInputStream,
2913            @IfdType int ifdType) throws IOException {
2914        if (dataInputStream.mPosition + 2 > dataInputStream.mLength) {
2915            // Return if there is no data from the offset.
2916            return;
2917        }
2918        // See TIFF 6.0 Section 2: TIFF Structure, Figure 1.
2919        short numberOfDirectoryEntry = dataInputStream.readShort();
2920        if (dataInputStream.mPosition + 12 * numberOfDirectoryEntry > dataInputStream.mLength) {
2921            // Return if the size of entries is too big.
2922            return;
2923        }
2924
2925        if (DEBUG) {
2926            Log.d(TAG, "numberOfDirectoryEntry: " + numberOfDirectoryEntry);
2927        }
2928
2929        // See TIFF 6.0 Section 2: TIFF Structure, "Image File Directory".
2930        for (short i = 0; i < numberOfDirectoryEntry; ++i) {
2931            int tagNumber = dataInputStream.readUnsignedShort();
2932            int dataFormat = dataInputStream.readUnsignedShort();
2933            int numberOfComponents = dataInputStream.readInt();
2934            // Next four bytes is for data offset or value.
2935            long nextEntryOffset = dataInputStream.peek() + 4;
2936
2937            // Look up a corresponding tag from tag number
2938            ExifTag tag = (ExifTag) sExifTagMapsForReading[ifdType].get(tagNumber);
2939
2940            if (DEBUG) {
2941                Log.d(TAG, String.format("ifdType: %d, tagNumber: %d, tagName: %s, dataFormat: %d, "
2942                        + "numberOfComponents: %d", ifdType, tagNumber,
2943                        tag != null ? tag.name : null, dataFormat, numberOfComponents));
2944            }
2945
2946            long byteCount = 0;
2947            boolean valid = false;
2948            if (tag == null) {
2949                Log.w(TAG, "Skip the tag entry since tag number is not defined: " + tagNumber);
2950            } else if (dataFormat <= 0 || dataFormat >= IFD_FORMAT_BYTES_PER_FORMAT.length) {
2951                Log.w(TAG, "Skip the tag entry since data format is invalid: " + dataFormat);
2952            } else {
2953                byteCount = (long) numberOfComponents * IFD_FORMAT_BYTES_PER_FORMAT[dataFormat];
2954                if (byteCount < 0 || byteCount > Integer.MAX_VALUE) {
2955                    Log.w(TAG, "Skip the tag entry since the number of components is invalid: "
2956                            + numberOfComponents);
2957                } else {
2958                    valid = true;
2959                }
2960            }
2961            if (!valid) {
2962                dataInputStream.seek(nextEntryOffset);
2963                continue;
2964            }
2965
2966            // Read a value from data field or seek to the value offset which is stored in data
2967            // field if the size of the entry value is bigger than 4.
2968            if (byteCount > 4) {
2969                int offset = dataInputStream.readInt();
2970                if (DEBUG) {
2971                    Log.d(TAG, "seek to data offset: " + offset);
2972                }
2973                if (mMimeType == IMAGE_TYPE_ORF) {
2974                    if (tag.name == TAG_MAKER_NOTE) {
2975                        // Save offset value for reading thumbnail
2976                        mOrfMakerNoteOffset = offset;
2977                    } else if (ifdType == IFD_TYPE_ORF_MAKER_NOTE
2978                            && tag.name == TAG_ORF_THUMBNAIL_IMAGE) {
2979                        // Retrieve & update values for thumbnail offset and length values for ORF
2980                        mOrfThumbnailOffset = offset;
2981                        mOrfThumbnailLength = numberOfComponents;
2982
2983                        ExifAttribute compressionAttribute =
2984                                ExifAttribute.createUShort(DATA_JPEG, mExifByteOrder);
2985                        ExifAttribute jpegInterchangeFormatAttribute =
2986                                ExifAttribute.createULong(mOrfThumbnailOffset, mExifByteOrder);
2987                        ExifAttribute jpegInterchangeFormatLengthAttribute =
2988                                ExifAttribute.createULong(mOrfThumbnailLength, mExifByteOrder);
2989
2990                        mAttributes[IFD_TYPE_THUMBNAIL].put(TAG_COMPRESSION, compressionAttribute);
2991                        mAttributes[IFD_TYPE_THUMBNAIL].put(TAG_JPEG_INTERCHANGE_FORMAT,
2992                                jpegInterchangeFormatAttribute);
2993                        mAttributes[IFD_TYPE_THUMBNAIL].put(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH,
2994                                jpegInterchangeFormatLengthAttribute);
2995                    }
2996                } else if (mMimeType == IMAGE_TYPE_RW2) {
2997                    if (tag.name == TAG_RW2_JPG_FROM_RAW) {
2998                        mRw2JpgFromRawOffset = offset;
2999                    }
3000                }
3001                if (offset + byteCount <= dataInputStream.mLength) {
3002                    dataInputStream.seek(offset);
3003                } else {
3004                    // Skip if invalid data offset.
3005                    Log.w(TAG, "Skip the tag entry since data offset is invalid: " + offset);
3006                    dataInputStream.seek(nextEntryOffset);
3007                    continue;
3008                }
3009            }
3010
3011            // Recursively parse IFD when a IFD pointer tag appears.
3012            Object nextIfdType = sExifPointerTagMap.get(tagNumber);
3013            if (DEBUG) {
3014                Log.d(TAG, "nextIfdType: " + nextIfdType + " byteCount: " + byteCount);
3015            }
3016
3017            if (nextIfdType != null) {
3018                long offset = -1L;
3019                // Get offset from data field
3020                switch (dataFormat) {
3021                    case IFD_FORMAT_USHORT: {
3022                        offset = dataInputStream.readUnsignedShort();
3023                        break;
3024                    }
3025                    case IFD_FORMAT_SSHORT: {
3026                        offset = dataInputStream.readShort();
3027                        break;
3028                    }
3029                    case IFD_FORMAT_ULONG: {
3030                        offset = dataInputStream.readUnsignedInt();
3031                        break;
3032                    }
3033                    case IFD_FORMAT_SLONG:
3034                    case IFD_FORMAT_IFD: {
3035                        offset = dataInputStream.readInt();
3036                        break;
3037                    }
3038                    default: {
3039                        // Nothing to do
3040                        break;
3041                    }
3042                }
3043                if (DEBUG) {
3044                    Log.d(TAG, String.format("Offset: %d, tagName: %s", offset, tag.name));
3045                }
3046                if (offset > 0L && offset < dataInputStream.mLength) {
3047                    dataInputStream.seek(offset);
3048                    readImageFileDirectory(dataInputStream, (int) nextIfdType);
3049                } else {
3050                    Log.w(TAG, "Skip jump into the IFD since its offset is invalid: " + offset);
3051                }
3052
3053                dataInputStream.seek(nextEntryOffset);
3054                continue;
3055            }
3056
3057            byte[] bytes = new byte[(int) byteCount];
3058            dataInputStream.readFully(bytes);
3059            ExifAttribute attribute = new ExifAttribute(dataFormat, numberOfComponents, bytes);
3060            mAttributes[ifdType].put(tag.name, attribute);
3061
3062            // DNG files have a DNG Version tag specifying the version of specifications that the
3063            // image file is following.
3064            // See http://fileformats.archiveteam.org/wiki/DNG
3065            if (tag.name == TAG_DNG_VERSION) {
3066                mMimeType = IMAGE_TYPE_DNG;
3067            }
3068
3069            // PEF files have a Make or Model tag that begins with "PENTAX" or a compression tag
3070            // that is 65535.
3071            // See http://fileformats.archiveteam.org/wiki/Pentax_PEF
3072            if (((tag.name == TAG_MAKE || tag.name == TAG_MODEL)
3073                    && attribute.getStringValue(mExifByteOrder).contains(PEF_SIGNATURE))
3074                    || (tag.name == TAG_COMPRESSION
3075                    && attribute.getIntValue(mExifByteOrder) == 65535)) {
3076                mMimeType = IMAGE_TYPE_PEF;
3077            }
3078
3079            // Seek to next tag offset
3080            if (dataInputStream.peek() != nextEntryOffset) {
3081                dataInputStream.seek(nextEntryOffset);
3082            }
3083        }
3084
3085        if (dataInputStream.peek() + 4 <= dataInputStream.mLength) {
3086            int nextIfdOffset = dataInputStream.readInt();
3087            if (DEBUG) {
3088                Log.d(TAG, String.format("nextIfdOffset: %d", nextIfdOffset));
3089            }
3090            // The next IFD offset needs to be bigger than 8
3091            // since the first IFD offset is at least 8.
3092            if (nextIfdOffset > 8 && nextIfdOffset < dataInputStream.mLength) {
3093                dataInputStream.seek(nextIfdOffset);
3094                if (mAttributes[IFD_TYPE_THUMBNAIL].isEmpty()) {
3095                    // Do not overwrite thumbnail IFD data if it alreay exists.
3096                    readImageFileDirectory(dataInputStream, IFD_TYPE_THUMBNAIL);
3097                } else if (mAttributes[IFD_TYPE_PREVIEW].isEmpty()) {
3098                    readImageFileDirectory(dataInputStream, IFD_TYPE_PREVIEW);
3099                }
3100            }
3101        }
3102    }
3103
3104    /**
3105     * JPEG compressed images do not contain IMAGE_LENGTH & IMAGE_WIDTH tags.
3106     * This value uses JpegInterchangeFormat(JPEG data offset) value, and calls getJpegAttributes()
3107     * to locate SOF(Start of Frame) marker and update the image length & width values.
3108     * See JEITA CP-3451C Table 5 and Section 4.8.1. B.
3109     */
3110    private void retrieveJpegImageSize(ByteOrderedDataInputStream in, int imageType)
3111            throws IOException {
3112        // Check if image already has IMAGE_LENGTH & IMAGE_WIDTH values
3113        ExifAttribute imageLengthAttribute =
3114                (ExifAttribute) mAttributes[imageType].get(TAG_IMAGE_LENGTH);
3115        ExifAttribute imageWidthAttribute =
3116                (ExifAttribute) mAttributes[imageType].get(TAG_IMAGE_WIDTH);
3117
3118        if (imageLengthAttribute == null || imageWidthAttribute == null) {
3119            // Find if offset for JPEG data exists
3120            ExifAttribute jpegInterchangeFormatAttribute =
3121                    (ExifAttribute) mAttributes[imageType].get(TAG_JPEG_INTERCHANGE_FORMAT);
3122            if (jpegInterchangeFormatAttribute != null) {
3123                int jpegInterchangeFormat =
3124                        jpegInterchangeFormatAttribute.getIntValue(mExifByteOrder);
3125
3126                // Searches for SOF marker in JPEG data and updates IMAGE_LENGTH & IMAGE_WIDTH tags
3127                getJpegAttributes(in, jpegInterchangeFormat, imageType);
3128            }
3129        }
3130    }
3131
3132    // Sets thumbnail offset & length attributes based on JpegInterchangeFormat or StripOffsets tags
3133    private void setThumbnailData(ByteOrderedDataInputStream in) throws IOException {
3134        HashMap thumbnailData = mAttributes[IFD_TYPE_THUMBNAIL];
3135
3136        ExifAttribute compressionAttribute =
3137                (ExifAttribute) thumbnailData.get(TAG_COMPRESSION);
3138        if (compressionAttribute != null) {
3139            mThumbnailCompression = compressionAttribute.getIntValue(mExifByteOrder);
3140            switch (mThumbnailCompression) {
3141                case DATA_JPEG: {
3142                    handleThumbnailFromJfif(in, thumbnailData);
3143                    break;
3144                }
3145                case DATA_UNCOMPRESSED:
3146                case DATA_JPEG_COMPRESSED: {
3147                    if (isSupportedDataType(thumbnailData)) {
3148                        handleThumbnailFromStrips(in, thumbnailData);
3149                    }
3150                    break;
3151                }
3152            }
3153        } else {
3154            // Thumbnail data may not contain Compression tag value
3155            handleThumbnailFromJfif(in, thumbnailData);
3156        }
3157    }
3158
3159    // Check JpegInterchangeFormat(JFIF) tags to retrieve thumbnail offset & length values
3160    // and reads the corresponding bytes if stream does not support seek function
3161    private void handleThumbnailFromJfif(ByteOrderedDataInputStream in, HashMap thumbnailData)
3162            throws IOException {
3163        ExifAttribute jpegInterchangeFormatAttribute =
3164                (ExifAttribute) thumbnailData.get(TAG_JPEG_INTERCHANGE_FORMAT);
3165        ExifAttribute jpegInterchangeFormatLengthAttribute =
3166                (ExifAttribute) thumbnailData.get(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
3167        if (jpegInterchangeFormatAttribute != null
3168                && jpegInterchangeFormatLengthAttribute != null) {
3169            int thumbnailOffset = jpegInterchangeFormatAttribute.getIntValue(mExifByteOrder);
3170            int thumbnailLength = jpegInterchangeFormatLengthAttribute.getIntValue(mExifByteOrder);
3171
3172            // The following code limits the size of thumbnail size not to overflow EXIF data area.
3173            thumbnailLength = Math.min(thumbnailLength, in.available() - thumbnailOffset);
3174            if (mMimeType == IMAGE_TYPE_JPEG || mMimeType == IMAGE_TYPE_RAF
3175                    || mMimeType == IMAGE_TYPE_RW2) {
3176                thumbnailOffset += mExifOffset;
3177            } else if (mMimeType == IMAGE_TYPE_ORF) {
3178                // Update offset value since RAF files have IFD data preceding MakerNote data.
3179                thumbnailOffset += mOrfMakerNoteOffset;
3180            }
3181            if (DEBUG) {
3182                Log.d(TAG, "Setting thumbnail attributes with offset: " + thumbnailOffset
3183                        + ", length: " + thumbnailLength);
3184            }
3185            if (thumbnailOffset > 0 && thumbnailLength > 0) {
3186                mHasThumbnail = true;
3187                mThumbnailOffset = thumbnailOffset;
3188                mThumbnailLength = thumbnailLength;
3189                mThumbnailCompression = DATA_JPEG;
3190
3191                if (mFilename == null && mAssetInputStream == null
3192                        && mSeekableFileDescriptor == null) {
3193                    // Save the thumbnail in memory if the input doesn't support reading again.
3194                    byte[] thumbnailBytes = new byte[thumbnailLength];
3195                    in.seek(thumbnailOffset);
3196                    in.readFully(thumbnailBytes);
3197                    mThumbnailBytes = thumbnailBytes;
3198                }
3199            }
3200        }
3201    }
3202
3203    // Check StripOffsets & StripByteCounts tags to retrieve thumbnail offset & length values
3204    private void handleThumbnailFromStrips(ByteOrderedDataInputStream in, HashMap thumbnailData)
3205            throws IOException {
3206        ExifAttribute stripOffsetsAttribute =
3207                (ExifAttribute) thumbnailData.get(TAG_STRIP_OFFSETS);
3208        ExifAttribute stripByteCountsAttribute =
3209                (ExifAttribute) thumbnailData.get(TAG_STRIP_BYTE_COUNTS);
3210
3211        if (stripOffsetsAttribute != null && stripByteCountsAttribute != null) {
3212            long[] stripOffsets =
3213                    (long[]) stripOffsetsAttribute.getValue(mExifByteOrder);
3214            long[] stripByteCounts =
3215                    (long[]) stripByteCountsAttribute.getValue(mExifByteOrder);
3216
3217            // Set thumbnail byte array data for non-consecutive strip bytes
3218            byte[] totalStripBytes =
3219                    new byte[(int) Arrays.stream(stripByteCounts).sum()];
3220
3221            int bytesRead = 0;
3222            int bytesAdded = 0;
3223            for (int i = 0; i < stripOffsets.length; i++) {
3224                int stripOffset = (int) stripOffsets[i];
3225                int stripByteCount = (int) stripByteCounts[i];
3226
3227                // Skip to offset
3228                int skipBytes = stripOffset - bytesRead;
3229                if (skipBytes < 0) {
3230                    Log.d(TAG, "Invalid strip offset value");
3231                }
3232                in.seek(skipBytes);
3233                bytesRead += skipBytes;
3234
3235                // Read strip bytes
3236                byte[] stripBytes = new byte[stripByteCount];
3237                in.read(stripBytes);
3238                bytesRead += stripByteCount;
3239
3240                // Add bytes to array
3241                System.arraycopy(stripBytes, 0, totalStripBytes, bytesAdded,
3242                        stripBytes.length);
3243                bytesAdded += stripBytes.length;
3244            }
3245
3246            mHasThumbnail = true;
3247            mThumbnailBytes = totalStripBytes;
3248            mThumbnailLength = totalStripBytes.length;
3249        }
3250    }
3251
3252    // Check if thumbnail data type is currently supported or not
3253    private boolean isSupportedDataType(HashMap thumbnailData) throws IOException {
3254        ExifAttribute bitsPerSampleAttribute =
3255                (ExifAttribute) thumbnailData.get(TAG_BITS_PER_SAMPLE);
3256        if (bitsPerSampleAttribute != null) {
3257            int[] bitsPerSampleValue = (int[]) bitsPerSampleAttribute.getValue(mExifByteOrder);
3258
3259            if (Arrays.equals(BITS_PER_SAMPLE_RGB, bitsPerSampleValue)) {
3260                return true;
3261            }
3262
3263            // See DNG Specification 1.4.0.0. Section 3, Compression.
3264            if (mMimeType == IMAGE_TYPE_DNG) {
3265                ExifAttribute photometricInterpretationAttribute =
3266                        (ExifAttribute) thumbnailData.get(TAG_PHOTOMETRIC_INTERPRETATION);
3267                if (photometricInterpretationAttribute != null) {
3268                    int photometricInterpretationValue
3269                            = photometricInterpretationAttribute.getIntValue(mExifByteOrder);
3270                    if ((photometricInterpretationValue == PHOTOMETRIC_INTERPRETATION_BLACK_IS_ZERO
3271                            && Arrays.equals(bitsPerSampleValue, BITS_PER_SAMPLE_GREYSCALE_2))
3272                            || ((photometricInterpretationValue == PHOTOMETRIC_INTERPRETATION_YCBCR)
3273                            && (Arrays.equals(bitsPerSampleValue, BITS_PER_SAMPLE_RGB)))) {
3274                        return true;
3275                    } else {
3276                        // TODO: Add support for lossless Huffman JPEG data
3277                    }
3278                }
3279            }
3280        }
3281        if (DEBUG) {
3282            Log.d(TAG, "Unsupported data type value");
3283        }
3284        return false;
3285    }
3286
3287    // Returns true if the image length and width values are <= 512.
3288    // See Section 4.8 of http://standardsproposals.bsigroup.com/Home/getPDF/567
3289    private boolean isThumbnail(HashMap map) throws IOException {
3290        ExifAttribute imageLengthAttribute = (ExifAttribute) map.get(TAG_IMAGE_LENGTH);
3291        ExifAttribute imageWidthAttribute = (ExifAttribute) map.get(TAG_IMAGE_WIDTH);
3292
3293        if (imageLengthAttribute != null && imageWidthAttribute != null) {
3294            int imageLengthValue = imageLengthAttribute.getIntValue(mExifByteOrder);
3295            int imageWidthValue = imageWidthAttribute.getIntValue(mExifByteOrder);
3296            if (imageLengthValue <= MAX_THUMBNAIL_SIZE && imageWidthValue <= MAX_THUMBNAIL_SIZE) {
3297                return true;
3298            }
3299        }
3300        return false;
3301    }
3302
3303    // Validate primary, preview, thumbnail image data by comparing image size
3304    private void validateImages(InputStream in) throws IOException {
3305        // Swap images based on size (primary > preview > thumbnail)
3306        swapBasedOnImageSize(IFD_TYPE_PRIMARY, IFD_TYPE_PREVIEW);
3307        swapBasedOnImageSize(IFD_TYPE_PRIMARY, IFD_TYPE_THUMBNAIL);
3308        swapBasedOnImageSize(IFD_TYPE_PREVIEW, IFD_TYPE_THUMBNAIL);
3309
3310        // Check if image has PixelXDimension/PixelYDimension tags, which contain valid image
3311        // sizes, excluding padding at the right end or bottom end of the image to make sure that
3312        // the values are multiples of 64. See JEITA CP-3451C Table 5 and Section 4.8.1. B.
3313        ExifAttribute pixelXDimAttribute =
3314                (ExifAttribute) mAttributes[IFD_TYPE_EXIF].get(TAG_PIXEL_X_DIMENSION);
3315        ExifAttribute pixelYDimAttribute =
3316                (ExifAttribute) mAttributes[IFD_TYPE_EXIF].get(TAG_PIXEL_Y_DIMENSION);
3317        if (pixelXDimAttribute != null && pixelYDimAttribute != null) {
3318            mAttributes[IFD_TYPE_PRIMARY].put(TAG_IMAGE_WIDTH, pixelXDimAttribute);
3319            mAttributes[IFD_TYPE_PRIMARY].put(TAG_IMAGE_LENGTH, pixelYDimAttribute);
3320        }
3321
3322        // Check whether thumbnail image exists and whether preview image satisfies the thumbnail
3323        // image requirements
3324        if (mAttributes[IFD_TYPE_THUMBNAIL].isEmpty()) {
3325            if (isThumbnail(mAttributes[IFD_TYPE_PREVIEW])) {
3326                mAttributes[IFD_TYPE_THUMBNAIL] = mAttributes[IFD_TYPE_PREVIEW];
3327                mAttributes[IFD_TYPE_PREVIEW] = new HashMap();
3328            }
3329        }
3330
3331        // Check if the thumbnail image satisfies the thumbnail size requirements
3332        if (!isThumbnail(mAttributes[IFD_TYPE_THUMBNAIL])) {
3333            Log.d(TAG, "No image meets the size requirements of a thumbnail image.");
3334        }
3335    }
3336
3337    /**
3338     * If image is uncompressed, ImageWidth/Length tags are used to store size info.
3339     * However, uncompressed images often store extra pixels around the edges of the final image,
3340     * which results in larger values for TAG_IMAGE_WIDTH and TAG_IMAGE_LENGTH tags.
3341     * This method corrects those tag values by checking first the values of TAG_DEFAULT_CROP_SIZE
3342     * See DNG Specification 1.4.0.0. Section 4. (DefaultCropSize)
3343     *
3344     * If image is a RW2 file, valid image sizes are stored in SensorBorder tags.
3345     * See tiff_parser.cc GetFullDimension32()
3346     * */
3347    private void updateImageSizeValues(ByteOrderedDataInputStream in, int imageType)
3348            throws IOException {
3349        // Uncompressed image valid image size values
3350        ExifAttribute defaultCropSizeAttribute =
3351                (ExifAttribute) mAttributes[imageType].get(TAG_DEFAULT_CROP_SIZE);
3352        // RW2 image valid image size values
3353        ExifAttribute topBorderAttribute =
3354                (ExifAttribute) mAttributes[imageType].get(TAG_RW2_SENSOR_TOP_BORDER);
3355        ExifAttribute leftBorderAttribute =
3356                (ExifAttribute) mAttributes[imageType].get(TAG_RW2_SENSOR_LEFT_BORDER);
3357        ExifAttribute bottomBorderAttribute =
3358                (ExifAttribute) mAttributes[imageType].get(TAG_RW2_SENSOR_BOTTOM_BORDER);
3359        ExifAttribute rightBorderAttribute =
3360                (ExifAttribute) mAttributes[imageType].get(TAG_RW2_SENSOR_RIGHT_BORDER);
3361
3362        if (defaultCropSizeAttribute != null) {
3363            // Update for uncompressed image
3364            ExifAttribute defaultCropSizeXAttribute, defaultCropSizeYAttribute;
3365            if (defaultCropSizeAttribute.format == IFD_FORMAT_URATIONAL) {
3366                Rational[] defaultCropSizeValue =
3367                        (Rational[]) defaultCropSizeAttribute.getValue(mExifByteOrder);
3368                defaultCropSizeXAttribute =
3369                        ExifAttribute.createURational(defaultCropSizeValue[0], mExifByteOrder);
3370                defaultCropSizeYAttribute =
3371                        ExifAttribute.createURational(defaultCropSizeValue[1], mExifByteOrder);
3372            } else {
3373                int[] defaultCropSizeValue =
3374                        (int[]) defaultCropSizeAttribute.getValue(mExifByteOrder);
3375                defaultCropSizeXAttribute =
3376                        ExifAttribute.createUShort(defaultCropSizeValue[0], mExifByteOrder);
3377                defaultCropSizeYAttribute =
3378                        ExifAttribute.createUShort(defaultCropSizeValue[1], mExifByteOrder);
3379            }
3380            mAttributes[imageType].put(TAG_IMAGE_WIDTH, defaultCropSizeXAttribute);
3381            mAttributes[imageType].put(TAG_IMAGE_LENGTH, defaultCropSizeYAttribute);
3382        } else if (topBorderAttribute != null && leftBorderAttribute != null &&
3383                bottomBorderAttribute != null && rightBorderAttribute != null) {
3384            // Update for RW2 image
3385            int topBorderValue = topBorderAttribute.getIntValue(mExifByteOrder);
3386            int bottomBorderValue = bottomBorderAttribute.getIntValue(mExifByteOrder);
3387            int rightBorderValue = rightBorderAttribute.getIntValue(mExifByteOrder);
3388            int leftBorderValue = leftBorderAttribute.getIntValue(mExifByteOrder);
3389            if (bottomBorderValue > topBorderValue && rightBorderValue > leftBorderValue) {
3390                int length = bottomBorderValue - topBorderValue;
3391                int width = rightBorderValue - leftBorderValue;
3392                ExifAttribute imageLengthAttribute =
3393                        ExifAttribute.createUShort(length, mExifByteOrder);
3394                ExifAttribute imageWidthAttribute =
3395                        ExifAttribute.createUShort(width, mExifByteOrder);
3396                mAttributes[imageType].put(TAG_IMAGE_LENGTH, imageLengthAttribute);
3397                mAttributes[imageType].put(TAG_IMAGE_WIDTH, imageWidthAttribute);
3398            }
3399        } else {
3400            retrieveJpegImageSize(in, imageType);
3401        }
3402    }
3403
3404    // Writes an Exif segment into the given output stream.
3405    private int writeExifSegment(ByteOrderedDataOutputStream dataOutputStream,
3406            int exifOffsetFromBeginning) throws IOException {
3407        // The following variables are for calculating each IFD tag group size in bytes.
3408        int[] ifdOffsets = new int[EXIF_TAGS.length];
3409        int[] ifdDataSizes = new int[EXIF_TAGS.length];
3410
3411        // Remove IFD pointer tags (we'll re-add it later.)
3412        for (ExifTag tag : EXIF_POINTER_TAGS) {
3413            removeAttribute(tag.name);
3414        }
3415        // Remove old thumbnail data
3416        removeAttribute(JPEG_INTERCHANGE_FORMAT_TAG.name);
3417        removeAttribute(JPEG_INTERCHANGE_FORMAT_LENGTH_TAG.name);
3418
3419        // Remove null value tags.
3420        for (int ifdType = 0; ifdType < EXIF_TAGS.length; ++ifdType) {
3421            for (Object obj : mAttributes[ifdType].entrySet().toArray()) {
3422                final Map.Entry entry = (Map.Entry) obj;
3423                if (entry.getValue() == null) {
3424                    mAttributes[ifdType].remove(entry.getKey());
3425                }
3426            }
3427        }
3428
3429        // Add IFD pointer tags. The next offset of primary image TIFF IFD will have thumbnail IFD
3430        // offset when there is one or more tags in the thumbnail IFD.
3431        if (!mAttributes[IFD_TYPE_EXIF].isEmpty()) {
3432            mAttributes[IFD_TYPE_PRIMARY].put(EXIF_POINTER_TAGS[1].name,
3433                    ExifAttribute.createULong(0, mExifByteOrder));
3434        }
3435        if (!mAttributes[IFD_TYPE_GPS].isEmpty()) {
3436            mAttributes[IFD_TYPE_PRIMARY].put(EXIF_POINTER_TAGS[2].name,
3437                    ExifAttribute.createULong(0, mExifByteOrder));
3438        }
3439        if (!mAttributes[IFD_TYPE_INTEROPERABILITY].isEmpty()) {
3440            mAttributes[IFD_TYPE_EXIF].put(EXIF_POINTER_TAGS[3].name,
3441                    ExifAttribute.createULong(0, mExifByteOrder));
3442        }
3443        if (mHasThumbnail) {
3444            mAttributes[IFD_TYPE_THUMBNAIL].put(JPEG_INTERCHANGE_FORMAT_TAG.name,
3445                    ExifAttribute.createULong(0, mExifByteOrder));
3446            mAttributes[IFD_TYPE_THUMBNAIL].put(JPEG_INTERCHANGE_FORMAT_LENGTH_TAG.name,
3447                    ExifAttribute.createULong(mThumbnailLength, mExifByteOrder));
3448        }
3449
3450        // Calculate IFD group data area sizes. IFD group data area is assigned to save the entry
3451        // value which has a bigger size than 4 bytes.
3452        for (int i = 0; i < EXIF_TAGS.length; ++i) {
3453            int sum = 0;
3454            for (Map.Entry entry : (Set<Map.Entry>) mAttributes[i].entrySet()) {
3455                final ExifAttribute exifAttribute = (ExifAttribute) entry.getValue();
3456                final int size = exifAttribute.size();
3457                if (size > 4) {
3458                    sum += size;
3459                }
3460            }
3461            ifdDataSizes[i] += sum;
3462        }
3463
3464        // Calculate IFD offsets.
3465        int position = 8;
3466        for (int ifdType = 0; ifdType < EXIF_TAGS.length; ++ifdType) {
3467            if (!mAttributes[ifdType].isEmpty()) {
3468                ifdOffsets[ifdType] = position;
3469                position += 2 + mAttributes[ifdType].size() * 12 + 4 + ifdDataSizes[ifdType];
3470            }
3471        }
3472        if (mHasThumbnail) {
3473            int thumbnailOffset = position;
3474            mAttributes[IFD_TYPE_THUMBNAIL].put(JPEG_INTERCHANGE_FORMAT_TAG.name,
3475                    ExifAttribute.createULong(thumbnailOffset, mExifByteOrder));
3476            mThumbnailOffset = exifOffsetFromBeginning + thumbnailOffset;
3477            position += mThumbnailLength;
3478        }
3479
3480        // Calculate the total size
3481        int totalSize = position + 8;  // eight bytes is for header part.
3482        if (DEBUG) {
3483            Log.d(TAG, "totalSize length: " + totalSize);
3484            for (int i = 0; i < EXIF_TAGS.length; ++i) {
3485                Log.d(TAG, String.format("index: %d, offsets: %d, tag count: %d, data sizes: %d",
3486                        i, ifdOffsets[i], mAttributes[i].size(), ifdDataSizes[i]));
3487            }
3488        }
3489
3490        // Update IFD pointer tags with the calculated offsets.
3491        if (!mAttributes[IFD_TYPE_EXIF].isEmpty()) {
3492            mAttributes[IFD_TYPE_PRIMARY].put(EXIF_POINTER_TAGS[1].name,
3493                    ExifAttribute.createULong(ifdOffsets[IFD_TYPE_EXIF], mExifByteOrder));
3494        }
3495        if (!mAttributes[IFD_TYPE_GPS].isEmpty()) {
3496            mAttributes[IFD_TYPE_PRIMARY].put(EXIF_POINTER_TAGS[2].name,
3497                    ExifAttribute.createULong(ifdOffsets[IFD_TYPE_GPS], mExifByteOrder));
3498        }
3499        if (!mAttributes[IFD_TYPE_INTEROPERABILITY].isEmpty()) {
3500            mAttributes[IFD_TYPE_EXIF].put(EXIF_POINTER_TAGS[3].name, ExifAttribute.createULong(
3501                    ifdOffsets[IFD_TYPE_INTEROPERABILITY], mExifByteOrder));
3502        }
3503
3504        // Write TIFF Headers. See JEITA CP-3451C Section 4.5.2. Table 1.
3505        dataOutputStream.writeUnsignedShort(totalSize);
3506        dataOutputStream.write(IDENTIFIER_EXIF_APP1);
3507        dataOutputStream.writeShort(mExifByteOrder == ByteOrder.BIG_ENDIAN
3508                ? BYTE_ALIGN_MM : BYTE_ALIGN_II);
3509        dataOutputStream.setByteOrder(mExifByteOrder);
3510        dataOutputStream.writeUnsignedShort(START_CODE);
3511        dataOutputStream.writeUnsignedInt(IFD_OFFSET);
3512
3513        // Write IFD groups. See JEITA CP-3451C Section 4.5.8. Figure 9.
3514        for (int ifdType = 0; ifdType < EXIF_TAGS.length; ++ifdType) {
3515            if (!mAttributes[ifdType].isEmpty()) {
3516                // See JEITA CP-3451C Section 4.6.2: IFD structure.
3517                // Write entry count
3518                dataOutputStream.writeUnsignedShort(mAttributes[ifdType].size());
3519
3520                // Write entry info
3521                int dataOffset = ifdOffsets[ifdType] + 2 + mAttributes[ifdType].size() * 12 + 4;
3522                for (Map.Entry entry : (Set<Map.Entry>) mAttributes[ifdType].entrySet()) {
3523                    // Convert tag name to tag number.
3524                    final ExifTag tag =
3525                            (ExifTag) sExifTagMapsForWriting[ifdType].get(entry.getKey());
3526                    final int tagNumber = tag.number;
3527                    final ExifAttribute attribute = (ExifAttribute) entry.getValue();
3528                    final int size = attribute.size();
3529
3530                    dataOutputStream.writeUnsignedShort(tagNumber);
3531                    dataOutputStream.writeUnsignedShort(attribute.format);
3532                    dataOutputStream.writeInt(attribute.numberOfComponents);
3533                    if (size > 4) {
3534                        dataOutputStream.writeUnsignedInt(dataOffset);
3535                        dataOffset += size;
3536                    } else {
3537                        dataOutputStream.write(attribute.bytes);
3538                        // Fill zero up to 4 bytes
3539                        if (size < 4) {
3540                            for (int i = size; i < 4; ++i) {
3541                                dataOutputStream.writeByte(0);
3542                            }
3543                        }
3544                    }
3545                }
3546
3547                // Write the next offset. It writes the offset of thumbnail IFD if there is one or
3548                // more tags in the thumbnail IFD when the current IFD is the primary image TIFF
3549                // IFD; Otherwise 0.
3550                if (ifdType == 0 && !mAttributes[IFD_TYPE_THUMBNAIL].isEmpty()) {
3551                    dataOutputStream.writeUnsignedInt(ifdOffsets[IFD_TYPE_THUMBNAIL]);
3552                } else {
3553                    dataOutputStream.writeUnsignedInt(0);
3554                }
3555
3556                // Write values of data field exceeding 4 bytes after the next offset.
3557                for (Map.Entry entry : (Set<Map.Entry>) mAttributes[ifdType].entrySet()) {
3558                    ExifAttribute attribute = (ExifAttribute) entry.getValue();
3559
3560                    if (attribute.bytes.length > 4) {
3561                        dataOutputStream.write(attribute.bytes, 0, attribute.bytes.length);
3562                    }
3563                }
3564            }
3565        }
3566
3567        // Write thumbnail
3568        if (mHasThumbnail) {
3569            dataOutputStream.write(getThumbnailBytes());
3570        }
3571
3572        // Reset the byte order to big endian in order to write remaining parts of the JPEG file.
3573        dataOutputStream.setByteOrder(ByteOrder.BIG_ENDIAN);
3574
3575        return totalSize;
3576    }
3577
3578    /**
3579     * Determines the data format of EXIF entry value.
3580     *
3581     * @param entryValue The value to be determined.
3582     * @return Returns two data formats gussed as a pair in integer. If there is no two candidate
3583               data formats for the given entry value, returns {@code -1} in the second of the pair.
3584     */
3585    private static Pair<Integer, Integer> guessDataFormat(String entryValue) {
3586        // See TIFF 6.0 Section 2, "Image File Directory".
3587        // Take the first component if there are more than one component.
3588        if (entryValue.contains(",")) {
3589            String[] entryValues = entryValue.split(",");
3590            Pair<Integer, Integer> dataFormat = guessDataFormat(entryValues[0]);
3591            if (dataFormat.first == IFD_FORMAT_STRING) {
3592                return dataFormat;
3593            }
3594            for (int i = 1; i < entryValues.length; ++i) {
3595                final Pair<Integer, Integer> guessDataFormat = guessDataFormat(entryValues[i]);
3596                int first = -1, second = -1;
3597                if (guessDataFormat.first == dataFormat.first
3598                        || guessDataFormat.second == dataFormat.first) {
3599                    first = dataFormat.first;
3600                }
3601                if (dataFormat.second != -1 && (guessDataFormat.first == dataFormat.second
3602                        || guessDataFormat.second == dataFormat.second)) {
3603                    second = dataFormat.second;
3604                }
3605                if (first == -1 && second == -1) {
3606                    return new Pair<>(IFD_FORMAT_STRING, -1);
3607                }
3608                if (first == -1) {
3609                    dataFormat = new Pair<>(second, -1);
3610                    continue;
3611                }
3612                if (second == -1) {
3613                    dataFormat = new Pair<>(first, -1);
3614                    continue;
3615                }
3616            }
3617            return dataFormat;
3618        }
3619
3620        if (entryValue.contains("/")) {
3621            String[] rationalNumber = entryValue.split("/");
3622            if (rationalNumber.length == 2) {
3623                try {
3624                    long numerator = (long) Double.parseDouble(rationalNumber[0]);
3625                    long denominator = (long) Double.parseDouble(rationalNumber[1]);
3626                    if (numerator < 0L || denominator < 0L) {
3627                        return new Pair<>(IFD_FORMAT_SRATIONAL, -1);
3628                    }
3629                    if (numerator > Integer.MAX_VALUE || denominator > Integer.MAX_VALUE) {
3630                        return new Pair<>(IFD_FORMAT_URATIONAL, -1);
3631                    }
3632                    return new Pair<>(IFD_FORMAT_SRATIONAL, IFD_FORMAT_URATIONAL);
3633                } catch (NumberFormatException e)  {
3634                    // Ignored
3635                }
3636            }
3637            return new Pair<>(IFD_FORMAT_STRING, -1);
3638        }
3639        try {
3640            Long longValue = Long.parseLong(entryValue);
3641            if (longValue >= 0 && longValue <= 65535) {
3642                return new Pair<>(IFD_FORMAT_USHORT, IFD_FORMAT_ULONG);
3643            }
3644            if (longValue < 0) {
3645                return new Pair<>(IFD_FORMAT_SLONG, -1);
3646            }
3647            return new Pair<>(IFD_FORMAT_ULONG, -1);
3648        } catch (NumberFormatException e) {
3649            // Ignored
3650        }
3651        try {
3652            Double.parseDouble(entryValue);
3653            return new Pair<>(IFD_FORMAT_DOUBLE, -1);
3654        } catch (NumberFormatException e) {
3655            // Ignored
3656        }
3657        return new Pair<>(IFD_FORMAT_STRING, -1);
3658    }
3659
3660    // An input stream to parse EXIF data area, which can be written in either little or big endian
3661    // order.
3662    private static class ByteOrderedDataInputStream extends InputStream implements DataInput {
3663        private static final ByteOrder LITTLE_ENDIAN = ByteOrder.LITTLE_ENDIAN;
3664        private static final ByteOrder BIG_ENDIAN = ByteOrder.BIG_ENDIAN;
3665
3666        private DataInputStream mDataInputStream;
3667        private InputStream mInputStream;
3668        private ByteOrder mByteOrder = ByteOrder.BIG_ENDIAN;
3669        private final int mLength;
3670        private int mPosition;
3671
3672        public ByteOrderedDataInputStream(InputStream in) throws IOException {
3673            mInputStream = in;
3674            mDataInputStream = new DataInputStream(in);
3675            mLength = mDataInputStream.available();
3676            mPosition = 0;
3677            mDataInputStream.mark(mLength);
3678        }
3679
3680        public ByteOrderedDataInputStream(byte[] bytes) throws IOException {
3681            this(new ByteArrayInputStream(bytes));
3682        }
3683
3684        public void setByteOrder(ByteOrder byteOrder) {
3685            mByteOrder = byteOrder;
3686        }
3687
3688        public void seek(long byteCount) throws IOException {
3689            if (mPosition > byteCount) {
3690                mPosition = 0;
3691                mDataInputStream.reset();
3692                mDataInputStream.mark(mLength);
3693            } else {
3694                byteCount -= mPosition;
3695            }
3696
3697            if (skipBytes((int) byteCount) != (int) byteCount) {
3698                throw new IOException("Couldn't seek up to the byteCount");
3699            }
3700        }
3701
3702        public int peek() {
3703            return mPosition;
3704        }
3705
3706        @Override
3707        public int available() throws IOException {
3708            return mDataInputStream.available();
3709        }
3710
3711        @Override
3712        public int read() throws IOException {
3713            ++mPosition;
3714            return mDataInputStream.read();
3715        }
3716
3717        @Override
3718        public int readUnsignedByte() throws IOException {
3719            ++mPosition;
3720            return mDataInputStream.readUnsignedByte();
3721        }
3722
3723        @Override
3724        public String readLine() throws IOException {
3725            Log.d(TAG, "Currently unsupported");
3726            return null;
3727        }
3728
3729        @Override
3730        public boolean readBoolean() throws IOException {
3731            ++mPosition;
3732            return mDataInputStream.readBoolean();
3733        }
3734
3735        @Override
3736        public char readChar() throws IOException {
3737            mPosition += 2;
3738            return mDataInputStream.readChar();
3739        }
3740
3741        @Override
3742        public String readUTF() throws IOException {
3743            mPosition += 2;
3744            return mDataInputStream.readUTF();
3745        }
3746
3747        @Override
3748        public void readFully(byte[] buffer, int offset, int length) throws IOException {
3749            mPosition += length;
3750            if (mPosition > mLength) {
3751                throw new EOFException();
3752            }
3753            if (mDataInputStream.read(buffer, offset, length) != length) {
3754                throw new IOException("Couldn't read up to the length of buffer");
3755            }
3756        }
3757
3758        @Override
3759        public void readFully(byte[] buffer) throws IOException {
3760            mPosition += buffer.length;
3761            if (mPosition > mLength) {
3762                throw new EOFException();
3763            }
3764            if (mDataInputStream.read(buffer, 0, buffer.length) != buffer.length) {
3765                throw new IOException("Couldn't read up to the length of buffer");
3766            }
3767        }
3768
3769        @Override
3770        public byte readByte() throws IOException {
3771            ++mPosition;
3772            if (mPosition > mLength) {
3773                throw new EOFException();
3774            }
3775            int ch = mDataInputStream.read();
3776            if (ch < 0) {
3777                throw new EOFException();
3778            }
3779            return (byte) ch;
3780        }
3781
3782        @Override
3783        public short readShort() throws IOException {
3784            mPosition += 2;
3785            if (mPosition > mLength) {
3786                throw new EOFException();
3787            }
3788            int ch1 = mDataInputStream.read();
3789            int ch2 = mDataInputStream.read();
3790            if ((ch1 | ch2) < 0) {
3791                throw new EOFException();
3792            }
3793            if (mByteOrder == LITTLE_ENDIAN) {
3794                return (short) ((ch2 << 8) + (ch1));
3795            } else if (mByteOrder == BIG_ENDIAN) {
3796                return (short) ((ch1 << 8) + (ch2));
3797            }
3798            throw new IOException("Invalid byte order: " + mByteOrder);
3799        }
3800
3801        @Override
3802        public int readInt() throws IOException {
3803            mPosition += 4;
3804            if (mPosition > mLength) {
3805                throw new EOFException();
3806            }
3807            int ch1 = mDataInputStream.read();
3808            int ch2 = mDataInputStream.read();
3809            int ch3 = mDataInputStream.read();
3810            int ch4 = mDataInputStream.read();
3811            if ((ch1 | ch2 | ch3 | ch4) < 0) {
3812                throw new EOFException();
3813            }
3814            if (mByteOrder == LITTLE_ENDIAN) {
3815                return ((ch4 << 24) + (ch3 << 16) + (ch2 << 8) + ch1);
3816            } else if (mByteOrder == BIG_ENDIAN) {
3817                return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + ch4);
3818            }
3819            throw new IOException("Invalid byte order: " + mByteOrder);
3820        }
3821
3822        @Override
3823        public int skipBytes(int byteCount) throws IOException {
3824            int totalSkip = Math.min(byteCount, mLength - mPosition);
3825            int skipped = 0;
3826            while (skipped < totalSkip) {
3827                skipped += mDataInputStream.skipBytes(totalSkip - skipped);
3828            }
3829            mPosition += skipped;
3830            return skipped;
3831        }
3832
3833        public int readUnsignedShort() throws IOException {
3834            mPosition += 2;
3835            if (mPosition > mLength) {
3836                throw new EOFException();
3837            }
3838            int ch1 = mDataInputStream.read();
3839            int ch2 = mDataInputStream.read();
3840            if ((ch1 | ch2) < 0) {
3841                throw new EOFException();
3842            }
3843            if (mByteOrder == LITTLE_ENDIAN) {
3844                return ((ch2 << 8) + (ch1));
3845            } else if (mByteOrder == BIG_ENDIAN) {
3846                return ((ch1 << 8) + (ch2));
3847            }
3848            throw new IOException("Invalid byte order: " + mByteOrder);
3849        }
3850
3851        public long readUnsignedInt() throws IOException {
3852            return readInt() & 0xffffffffL;
3853        }
3854
3855        @Override
3856        public long readLong() throws IOException {
3857            mPosition += 8;
3858            if (mPosition > mLength) {
3859                throw new EOFException();
3860            }
3861            int ch1 = mDataInputStream.read();
3862            int ch2 = mDataInputStream.read();
3863            int ch3 = mDataInputStream.read();
3864            int ch4 = mDataInputStream.read();
3865            int ch5 = mDataInputStream.read();
3866            int ch6 = mDataInputStream.read();
3867            int ch7 = mDataInputStream.read();
3868            int ch8 = mDataInputStream.read();
3869            if ((ch1 | ch2 | ch3 | ch4 | ch5 | ch6 | ch7 | ch8) < 0) {
3870                throw new EOFException();
3871            }
3872            if (mByteOrder == LITTLE_ENDIAN) {
3873                return (((long) ch8 << 56) + ((long) ch7 << 48) + ((long) ch6 << 40)
3874                        + ((long) ch5 << 32) + ((long) ch4 << 24) + ((long) ch3 << 16)
3875                        + ((long) ch2 << 8) + (long) ch1);
3876            } else if (mByteOrder == BIG_ENDIAN) {
3877                return (((long) ch1 << 56) + ((long) ch2 << 48) + ((long) ch3 << 40)
3878                        + ((long) ch4 << 32) + ((long) ch5 << 24) + ((long) ch6 << 16)
3879                        + ((long) ch7 << 8) + (long) ch8);
3880            }
3881            throw new IOException("Invalid byte order: " + mByteOrder);
3882        }
3883
3884        @Override
3885        public float readFloat() throws IOException {
3886            return Float.intBitsToFloat(readInt());
3887        }
3888
3889        @Override
3890        public double readDouble() throws IOException {
3891            return Double.longBitsToDouble(readLong());
3892        }
3893    }
3894
3895    // An output stream to write EXIF data area, which can be written in either little or big endian
3896    // order.
3897    private static class ByteOrderedDataOutputStream extends FilterOutputStream {
3898        private final OutputStream mOutputStream;
3899        private ByteOrder mByteOrder;
3900
3901        public ByteOrderedDataOutputStream(OutputStream out, ByteOrder byteOrder) {
3902            super(out);
3903            mOutputStream = out;
3904            mByteOrder = byteOrder;
3905        }
3906
3907        public void setByteOrder(ByteOrder byteOrder) {
3908            mByteOrder = byteOrder;
3909        }
3910
3911        public void write(byte[] bytes) throws IOException {
3912            mOutputStream.write(bytes);
3913        }
3914
3915        public void write(byte[] bytes, int offset, int length) throws IOException {
3916            mOutputStream.write(bytes, offset, length);
3917        }
3918
3919        public void writeByte(int val) throws IOException {
3920            mOutputStream.write(val);
3921        }
3922
3923        public void writeShort(short val) throws IOException {
3924            if (mByteOrder == ByteOrder.LITTLE_ENDIAN) {
3925                mOutputStream.write((val >>> 0) & 0xFF);
3926                mOutputStream.write((val >>> 8) & 0xFF);
3927            } else if (mByteOrder == ByteOrder.BIG_ENDIAN) {
3928                mOutputStream.write((val >>> 8) & 0xFF);
3929                mOutputStream.write((val >>> 0) & 0xFF);
3930            }
3931        }
3932
3933        public void writeInt(int val) throws IOException {
3934            if (mByteOrder == ByteOrder.LITTLE_ENDIAN) {
3935                mOutputStream.write((val >>> 0) & 0xFF);
3936                mOutputStream.write((val >>> 8) & 0xFF);
3937                mOutputStream.write((val >>> 16) & 0xFF);
3938                mOutputStream.write((val >>> 24) & 0xFF);
3939            } else if (mByteOrder == ByteOrder.BIG_ENDIAN) {
3940                mOutputStream.write((val >>> 24) & 0xFF);
3941                mOutputStream.write((val >>> 16) & 0xFF);
3942                mOutputStream.write((val >>> 8) & 0xFF);
3943                mOutputStream.write((val >>> 0) & 0xFF);
3944            }
3945        }
3946
3947        public void writeUnsignedShort(int val) throws IOException {
3948            writeShort((short) val);
3949        }
3950
3951        public void writeUnsignedInt(long val) throws IOException {
3952            writeInt((int) val);
3953        }
3954    }
3955
3956    // Swaps image data based on image size
3957    private void swapBasedOnImageSize(@IfdType int firstIfdType, @IfdType int secondIfdType)
3958            throws IOException {
3959        if (mAttributes[firstIfdType].isEmpty() || mAttributes[secondIfdType].isEmpty()) {
3960            if (DEBUG) {
3961                Log.d(TAG, "Cannot perform swap since only one image data exists");
3962            }
3963            return;
3964        }
3965
3966        ExifAttribute firstImageLengthAttribute =
3967                (ExifAttribute) mAttributes[firstIfdType].get(TAG_IMAGE_LENGTH);
3968        ExifAttribute firstImageWidthAttribute =
3969                (ExifAttribute) mAttributes[firstIfdType].get(TAG_IMAGE_WIDTH);
3970        ExifAttribute secondImageLengthAttribute =
3971                (ExifAttribute) mAttributes[secondIfdType].get(TAG_IMAGE_LENGTH);
3972        ExifAttribute secondImageWidthAttribute =
3973                (ExifAttribute) mAttributes[secondIfdType].get(TAG_IMAGE_WIDTH);
3974
3975        if (firstImageLengthAttribute == null || firstImageWidthAttribute == null) {
3976            if (DEBUG) {
3977                Log.d(TAG, "First image does not contain valid size information");
3978            }
3979        } else if (secondImageLengthAttribute == null || secondImageWidthAttribute == null) {
3980            if (DEBUG) {
3981                Log.d(TAG, "Second image does not contain valid size information");
3982            }
3983        } else {
3984            int firstImageLengthValue = firstImageLengthAttribute.getIntValue(mExifByteOrder);
3985            int firstImageWidthValue = firstImageWidthAttribute.getIntValue(mExifByteOrder);
3986            int secondImageLengthValue = secondImageLengthAttribute.getIntValue(mExifByteOrder);
3987            int secondImageWidthValue = secondImageWidthAttribute.getIntValue(mExifByteOrder);
3988
3989            if (firstImageLengthValue < secondImageLengthValue &&
3990                    firstImageWidthValue < secondImageWidthValue) {
3991                HashMap tempMap = mAttributes[firstIfdType];
3992                mAttributes[firstIfdType] = mAttributes[secondIfdType];
3993                mAttributes[secondIfdType] = tempMap;
3994            }
3995        }
3996    }
3997
3998    // Checks if there is a match
3999    private boolean containsMatch(byte[] mainBytes, byte[] findBytes) {
4000        for (int i = 0; i < mainBytes.length - findBytes.length; i++) {
4001            for (int j = 0; j < findBytes.length; j++) {
4002                if (mainBytes[i + j] != findBytes[j]) {
4003                    break;
4004                }
4005                if (j == findBytes.length - 1) {
4006                    return true;
4007                }
4008            }
4009        }
4010        return false;
4011    }
4012}
4013