ExifInterface.java revision 36a20cdde3176f24279e2382f878cecdbecafa9d
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;
27
28import java.io.BufferedInputStream;
29import java.io.ByteArrayInputStream;
30import java.io.DataInputStream;
31import java.io.DataOutputStream;
32import java.io.EOFException;
33import java.io.File;
34import java.io.FileDescriptor;
35import java.io.FileInputStream;
36import java.io.FileNotFoundException;
37import java.io.FileOutputStream;
38import java.io.IOException;
39import java.io.InputStream;
40import java.io.OutputStream;
41import java.nio.ByteOrder;
42import java.nio.charset.Charset;
43import java.text.ParsePosition;
44import java.text.SimpleDateFormat;
45import java.util.Arrays;
46import java.util.Date;
47import java.util.HashMap;
48import java.util.Map;
49import java.util.Set;
50import java.util.TimeZone;
51import java.util.regex.Pattern;
52
53import libcore.io.IoUtils;
54import libcore.io.Streams;
55
56/**
57 * This is a class for reading and writing Exif tags in a JPEG file or a RAW image file.
58 * <p>
59 * Supported formats are: JPEG, DNG, CR2, NEF, NRW, ARW, RW2, ORF and RAF.
60 * <p>
61 * Attribute mutation is supported for JPEG image files.
62 */
63public class ExifInterface {
64    private static final String TAG = "ExifInterface";
65    private static final boolean DEBUG = false;
66
67    // The Exif tag names
68    /** Type is String. */
69    public static final String TAG_ARTIST = "Artist";
70    /** Type is int. */
71    public static final String TAG_BITS_PER_SAMPLE = "BitsPerSample";
72    /** Type is int. */
73    public static final String TAG_COMPRESSION = "Compression";
74    /** Type is String. */
75    public static final String TAG_COPYRIGHT = "Copyright";
76    /** Type is String. */
77    public static final String TAG_DATETIME = "DateTime";
78    /** Type is String. */
79    public static final String TAG_IMAGE_DESCRIPTION = "ImageDescription";
80    /** Type is int. */
81    public static final String TAG_IMAGE_LENGTH = "ImageLength";
82    /** Type is int. */
83    public static final String TAG_IMAGE_WIDTH = "ImageWidth";
84    /** Type is int. */
85    public static final String TAG_JPEG_INTERCHANGE_FORMAT = "JPEGInterchangeFormat";
86    /** Type is int. */
87    public static final String TAG_JPEG_INTERCHANGE_FORMAT_LENGTH = "JPEGInterchangeFormatLength";
88    /** Type is String. */
89    public static final String TAG_MAKE = "Make";
90    /** Type is String. */
91    public static final String TAG_MODEL = "Model";
92    /** Type is int. */
93    public static final String TAG_ORIENTATION = "Orientation";
94    /** Type is int. */
95    public static final String TAG_PHOTOMETRIC_INTERPRETATION = "PhotometricInterpretation";
96    /** Type is int. */
97    public static final String TAG_PLANAR_CONFIGURATION = "PlanarConfiguration";
98    /** Type is rational. */
99    public static final String TAG_PRIMARY_CHROMATICITIES = "PrimaryChromaticities";
100    /** Type is rational. */
101    public static final String TAG_REFERENCE_BLACK_WHITE = "ReferenceBlackWhite";
102    /** Type is int. */
103    public static final String TAG_RESOLUTION_UNIT = "ResolutionUnit";
104    /** Type is int. */
105    public static final String TAG_ROWS_PER_STRIP = "RowsPerStrip";
106    /** Type is int. */
107    public static final String TAG_SAMPLES_PER_PIXEL = "SamplesPerPixel";
108    /** Type is String. */
109    public static final String TAG_SOFTWARE = "Software";
110    /** Type is int. */
111    public static final String TAG_STRIP_BYTE_COUNTS = "StripByteCounts";
112    /** Type is int. */
113    public static final String TAG_STRIP_OFFSETS = "StripOffsets";
114    /** Type is int. */
115    public static final String TAG_TRANSFER_FUNCTION = "TransferFunction";
116    /** Type is rational. */
117    public static final String TAG_WHITE_POINT = "WhitePoint";
118    /** Type is rational. */
119    public static final String TAG_X_RESOLUTION = "XResolution";
120    /** Type is rational. */
121    public static final String TAG_Y_CB_CR_COEFFICIENTS = "YCbCrCoefficients";
122    /** Type is int. */
123    public static final String TAG_Y_CB_CR_POSITIONING = "YCbCrPositioning";
124    /** Type is int. */
125    public static final String TAG_Y_CB_CR_SUB_SAMPLING = "YCbCrSubSampling";
126    /** Type is rational. */
127    public static final String TAG_Y_RESOLUTION = "YResolution";
128    /** Type is rational. */
129    public static final String TAG_APERTURE_VALUE = "ApertureValue";
130    /** Type is rational. */
131    public static final String TAG_BRIGHTNESS_VALUE = "BrightnessValue";
132    /** Type is String. */
133    public static final String TAG_CFA_PATTERN = "CFAPattern";
134    /** Type is int. */
135    public static final String TAG_COLOR_SPACE = "ColorSpace";
136    /** Type is String. */
137    public static final String TAG_COMPONENTS_CONFIGURATION = "ComponentsConfiguration";
138    /** Type is rational. */
139    public static final String TAG_COMPRESSED_BITS_PER_PIXEL = "CompressedBitsPerPixel";
140    /** Type is int. */
141    public static final String TAG_CONTRAST = "Contrast";
142    /** Type is int. */
143    public static final String TAG_CUSTOM_RENDERED = "CustomRendered";
144    /** Type is String. */
145    public static final String TAG_DATETIME_DIGITIZED = "DateTimeDigitized";
146    /** Type is String. */
147    public static final String TAG_DATETIME_ORIGINAL = "DateTimeOriginal";
148    /** Type is String. */
149    public static final String TAG_DEVICE_SETTING_DESCRIPTION = "DeviceSettingDescription";
150    /** Type is double. */
151    public static final String TAG_DIGITAL_ZOOM_RATIO = "DigitalZoomRatio";
152    /** Type is String. */
153    public static final String TAG_EXIF_VERSION = "ExifVersion";
154    /** Type is double. */
155    public static final String TAG_EXPOSURE_BIAS_VALUE = "ExposureBiasValue";
156    /** Type is rational. */
157    public static final String TAG_EXPOSURE_INDEX = "ExposureIndex";
158    /** Type is int. */
159    public static final String TAG_EXPOSURE_MODE = "ExposureMode";
160    /** Type is int. */
161    public static final String TAG_EXPOSURE_PROGRAM = "ExposureProgram";
162    /** Type is double. */
163    public static final String TAG_EXPOSURE_TIME = "ExposureTime";
164    /** Type is String. */
165    public static final String TAG_F_NUMBER = "FNumber";
166    /** Type is String. */
167    public static final String TAG_APERTURE = "FNumber";
168    /** Type is String. */
169    public static final String TAG_FILE_SOURCE = "FileSource";
170    /** Type is int. */
171    public static final String TAG_FLASH = "Flash";
172    /** Type is rational. */
173    public static final String TAG_FLASH_ENERGY = "FlashEnergy";
174    /** Type is String. */
175    public static final String TAG_FLASHPIX_VERSION = "FlashpixVersion";
176    /** Type is rational. */
177    public static final String TAG_FOCAL_LENGTH = "FocalLength";
178    /** Type is int. */
179    public static final String TAG_FOCAL_LENGTH_IN_35MM_FILM = "FocalLengthIn35mmFilm";
180    /** Type is int. */
181    public static final String TAG_FOCAL_PLANE_RESOLUTION_UNIT = "FocalPlaneResolutionUnit";
182    /** Type is rational. */
183    public static final String TAG_FOCAL_PLANE_X_RESOLUTION = "FocalPlaneXResolution";
184    /** Type is rational. */
185    public static final String TAG_FOCAL_PLANE_Y_RESOLUTION = "FocalPlaneYResolution";
186    /** Type is rational. */
187    public static final String TAG_GAIN_CONTROL = "GainControl";
188    /** Type is String. */
189    public static final String TAG_ISO_SPEED_RATINGS = "ISOSpeedRatings";
190    /** Type is String. */
191    public static final String TAG_ISO = "ISOSpeedRatings";
192    /** Type is String. */
193    public static final String TAG_IMAGE_UNIQUE_ID = "ImageUniqueID";
194    /** Type is int. */
195    public static final String TAG_LIGHT_SOURCE = "LightSource";
196    /** Type is String. */
197    public static final String TAG_MAKER_NOTE = "MakerNote";
198    /** Type is rational. */
199    public static final String TAG_MAX_APERTURE_VALUE = "MaxApertureValue";
200    /** Type is int. */
201    public static final String TAG_METERING_MODE = "MeteringMode";
202    /** Type is String. */
203    public static final String TAG_OECF = "OECF";
204    /** Type is int. */
205    public static final String TAG_PIXEL_X_DIMENSION = "PixelXDimension";
206    /** Type is int. */
207    public static final String TAG_PIXEL_Y_DIMENSION = "PixelYDimension";
208    /** Type is String. */
209    public static final String TAG_RELATED_SOUND_FILE = "RelatedSoundFile";
210    /** Type is int. */
211    public static final String TAG_SATURATION = "Saturation";
212    /** Type is int. */
213    public static final String TAG_SCENE_CAPTURE_TYPE = "SceneCaptureType";
214    /** Type is String. */
215    public static final String TAG_SCENE_TYPE = "SceneType";
216    /** Type is int. */
217    public static final String TAG_SENSING_METHOD = "SensingMethod";
218    /** Type is int. */
219    public static final String TAG_SHARPNESS = "Sharpness";
220    /** Type is rational. */
221    public static final String TAG_SHUTTER_SPEED_VALUE = "ShutterSpeedValue";
222    /** Type is String. */
223    public static final String TAG_SPATIAL_FREQUENCY_RESPONSE = "SpatialFrequencyResponse";
224    /** Type is String. */
225    public static final String TAG_SPECTRAL_SENSITIVITY = "SpectralSensitivity";
226    /** Type is int. */
227    public static final String TAG_SUBSEC_TIME = "SubSecTime";
228    /** Type is int. @hide */
229    public static final String TAG_SUBSECTIME = "SubSecTime";
230    /** Type is int. */
231    public static final String TAG_SUBSEC_TIME_DIGITIZED = "SubSecTimeDigitized";
232    /** Type is int. */
233    public static final String TAG_SUBSEC_TIME_DIG = "SubSecTimeDigitized";
234    /** Type is int. */
235    public static final String TAG_SUBSEC_TIME_ORIG = "SubSecTimeOriginal";
236    /** Type is int. */
237    public static final String TAG_SUBSEC_TIME_ORIGINAL = "SubSecTimeOriginal";
238    /** Type is int. */
239    public static final String TAG_SUBJECT_AREA = "SubjectArea";
240    /** Type is double. */
241    public static final String TAG_SUBJECT_DISTANCE = "SubjectDistance";
242    /** Type is int. */
243    public static final String TAG_SUBJECT_DISTANCE_RANGE = "SubjectDistanceRange";
244    /** Type is int. */
245    public static final String TAG_SUBJECT_LOCATION = "SubjectLocation";
246    /** Type is String. */
247    public static final String TAG_USER_COMMENT = "UserComment";
248    /** Type is int. */
249    public static final String TAG_WHITE_BALANCE = "WhiteBalance";
250    /**
251     * The altitude (in meters) based on the reference in TAG_GPS_ALTITUDE_REF.
252     * Type is rational.
253     */
254    public static final String TAG_GPS_ALTITUDE = "GPSAltitude";
255    /**
256     * 0 if the altitude is above sea level. 1 if the altitude is below sea
257     * level. Type is int.
258     */
259    public static final String TAG_GPS_ALTITUDE_REF = "GPSAltitudeRef";
260    /** Type is String. */
261    public static final String TAG_GPS_AREA_INFORMATION = "GPSAreaInformation";
262    /** Type is rational. */
263    public static final String TAG_GPS_DOP = "GPSDOP";
264    /** Type is String. */
265    public static final String TAG_GPS_DATESTAMP = "GPSDateStamp";
266    /** Type is rational. */
267    public static final String TAG_GPS_DEST_BEARING = "GPSDestBearing";
268    /** Type is String. */
269    public static final String TAG_GPS_DEST_BEARING_REF = "GPSDestBearingRef";
270    /** Type is rational. */
271    public static final String TAG_GPS_DEST_DISTANCE = "GPSDestDistance";
272    /** Type is String. */
273    public static final String TAG_GPS_DEST_DISTANCE_REF = "GPSDestDistanceRef";
274    /** Type is rational. */
275    public static final String TAG_GPS_DEST_LATITUDE = "GPSDestLatitude";
276    /** Type is String. */
277    public static final String TAG_GPS_DEST_LATITUDE_REF = "GPSDestLatitudeRef";
278    /** Type is rational. */
279    public static final String TAG_GPS_DEST_LONGITUDE = "GPSDestLongitude";
280    /** Type is String. */
281    public static final String TAG_GPS_DEST_LONGITUDE_REF = "GPSDestLongitudeRef";
282    /** Type is int. */
283    public static final String TAG_GPS_DIFFERENTIAL = "GPSDifferential";
284    /** Type is rational. */
285    public static final String TAG_GPS_IMG_DIRECTION = "GPSImgDirection";
286    /** Type is String. */
287    public static final String TAG_GPS_IMG_DIRECTION_REF = "GPSImgDirectionRef";
288    /** String. Format is "num1/denom1,num2/denom2,num3/denom3". */
289    public static final String TAG_GPS_LATITUDE = "GPSLatitude";
290    /** Type is String. */
291    public static final String TAG_GPS_LATITUDE_REF = "GPSLatitudeRef";
292    /** String. Format is "num1/denom1,num2/denom2,num3/denom3". */
293    public static final String TAG_GPS_LONGITUDE = "GPSLongitude";
294    /** Type is String. */
295    public static final String TAG_GPS_LONGITUDE_REF = "GPSLongitudeRef";
296    /** Type is String. */
297    public static final String TAG_GPS_MAP_DATUM = "GPSMapDatum";
298    /** Type is String. */
299    public static final String TAG_GPS_MEASURE_MODE = "GPSMeasureMode";
300    /** Type is String. Name of GPS processing method used for location finding. */
301    public static final String TAG_GPS_PROCESSING_METHOD = "GPSProcessingMethod";
302    /** Type is String. */
303    public static final String TAG_GPS_SATELLITES = "GPSSatellites";
304    /** Type is rational. */
305    public static final String TAG_GPS_SPEED = "GPSSpeed";
306    /** Type is String. */
307    public static final String TAG_GPS_SPEED_REF = "GPSSpeedRef";
308    /** Type is String. */
309    public static final String TAG_GPS_STATUS = "GPSStatus";
310    /** Type is String. */
311    public static final String TAG_GPS_TIMESTAMP = "GPSTimeStamp";
312    /** Type is rational. */
313    public static final String TAG_GPS_TRACK = "GPSTrack";
314    /** Type is String. */
315    public static final String TAG_GPS_TRACK_REF = "GPSTrackRef";
316    /** Type is String. */
317    public static final String TAG_GPS_VERSION_ID = "GPSVersionID";
318    /** Type is String. */
319    public static final String TAG_INTEROPERABILITY_INDEX = "InteroperabilityIndex";
320    /** Type is int. */
321    public static final String TAG_THUMBNAIL_IMAGE_LENGTH = "ThumbnailImageLength";
322    /** Type is int. */
323    public static final String TAG_THUMBNAIL_IMAGE_WIDTH = "ThumbnailImageWidth";
324
325    // Private tags used for pointing the other IFD offset. The types of the following tags are int.
326    private static final String TAG_EXIF_IFD_POINTER = "ExifIFDPointer";
327    private static final String TAG_GPS_INFO_IFD_POINTER = "GPSInfoIFDPointer";
328    private static final String TAG_INTEROPERABILITY_IFD_POINTER = "InteroperabilityIFDPointer";
329
330    // Private tags used for thumbnail information.
331    private static final String TAG_HAS_THUMBNAIL = "hasThumbnail";
332    private static final String TAG_THUMBNAIL_OFFSET = "thumbnailOffset";
333    private static final String TAG_THUMBNAIL_LENGTH = "thumbnailLength";
334    private static final String TAG_THUMBNAIL_DATA = "thumbnailData";
335
336    // Constants used for the Orientation Exif tag.
337    public static final int ORIENTATION_UNDEFINED = 0;
338    public static final int ORIENTATION_NORMAL = 1;
339    public static final int ORIENTATION_FLIP_HORIZONTAL = 2;  // left right reversed mirror
340    public static final int ORIENTATION_ROTATE_180 = 3;
341    public static final int ORIENTATION_FLIP_VERTICAL = 4;  // upside down mirror
342    // flipped about top-left <--> bottom-right axis
343    public static final int ORIENTATION_TRANSPOSE = 5;
344    public static final int ORIENTATION_ROTATE_90 = 6;  // rotate 90 cw to right it
345    // flipped about top-right <--> bottom-left axis
346    public static final int ORIENTATION_TRANSVERSE = 7;
347    public static final int ORIENTATION_ROTATE_270 = 8;  // rotate 270 to right it
348
349    // Constants used for white balance
350    public static final int WHITEBALANCE_AUTO = 0;
351    public static final int WHITEBALANCE_MANUAL = 1;
352
353    private static final byte[] JPEG_SIGNATURE = new byte[] {(byte) 0xff, (byte) 0xd8, (byte) 0xff};
354    private static final int JPEG_SIGNATURE_SIZE = 3;
355
356    private static SimpleDateFormat sFormatter;
357
358    // See Exchangeable image file format for digital still cameras: Exif version 2.2.
359    // The following values are for parsing EXIF data area. There are tag groups in EXIF data area.
360    // They are called "Image File Directory". They have multiple data formats to cover various
361    // image metadata from GPS longitude to camera model name.
362
363    // Types of Exif byte alignments (see JEITA CP-3451 page 10)
364    private static final short BYTE_ALIGN_II = 0x4949;  // II: Intel order
365    private static final short BYTE_ALIGN_MM = 0x4d4d;  // MM: Motorola order
366
367    // Formats for the value in IFD entry (See TIFF 6.0 spec Types page 15).
368    private static final int IFD_FORMAT_BYTE = 1;
369    private static final int IFD_FORMAT_STRING = 2;
370    private static final int IFD_FORMAT_USHORT = 3;
371    private static final int IFD_FORMAT_ULONG = 4;
372    private static final int IFD_FORMAT_URATIONAL = 5;
373    private static final int IFD_FORMAT_SBYTE = 6;
374    private static final int IFD_FORMAT_UNDEFINED = 7;
375    private static final int IFD_FORMAT_SSHORT = 8;
376    private static final int IFD_FORMAT_SLONG = 9;
377    private static final int IFD_FORMAT_SRATIONAL = 10;
378    private static final int IFD_FORMAT_SINGLE = 11;
379    private static final int IFD_FORMAT_DOUBLE = 12;
380    // Sizes of the components of each IFD value format
381    private static final int[] IFD_FORMAT_BYTES_PER_FORMAT = new int[] {
382            0, 1, 1, 2, 4, 8, 1, 1, 2, 4, 8, 4, 8
383    };
384    private static final byte[] EXIF_ASCII_PREFIX = new byte[] {
385            0x41, 0x53, 0x43, 0x49, 0x49, 0x0, 0x0, 0x0
386    };
387
388    // A class for indicating EXIF tag.
389    private static class ExifTag {
390        public final int number;
391        public final String name;
392
393        private ExifTag(String name, int number) {
394            this.name = name;
395            this.number = number;
396        }
397    }
398
399    // Primary image IFD TIFF tags (See JEITA CP-3451 Table 14. page 54).
400    private static final ExifTag[] IFD_TIFF_TAGS = new ExifTag[] {
401            new ExifTag(TAG_IMAGE_WIDTH, 256),
402            new ExifTag(TAG_IMAGE_LENGTH, 257),
403            new ExifTag(TAG_BITS_PER_SAMPLE, 258),
404            new ExifTag(TAG_COMPRESSION, 259),
405            new ExifTag(TAG_PHOTOMETRIC_INTERPRETATION, 262),
406            new ExifTag(TAG_IMAGE_DESCRIPTION, 270),
407            new ExifTag(TAG_MAKE, 271),
408            new ExifTag(TAG_MODEL, 272),
409            new ExifTag(TAG_STRIP_OFFSETS, 273),
410            new ExifTag(TAG_ORIENTATION, 274),
411            new ExifTag(TAG_SAMPLES_PER_PIXEL, 277),
412            new ExifTag(TAG_ROWS_PER_STRIP, 278),
413            new ExifTag(TAG_STRIP_BYTE_COUNTS, 279),
414            new ExifTag(TAG_X_RESOLUTION, 282),
415            new ExifTag(TAG_Y_RESOLUTION, 283),
416            new ExifTag(TAG_PLANAR_CONFIGURATION, 284),
417            new ExifTag(TAG_RESOLUTION_UNIT, 296),
418            new ExifTag(TAG_TRANSFER_FUNCTION, 301),
419            new ExifTag(TAG_SOFTWARE, 305),
420            new ExifTag(TAG_DATETIME, 306),
421            new ExifTag(TAG_ARTIST, 315),
422            new ExifTag(TAG_WHITE_POINT, 318),
423            new ExifTag(TAG_PRIMARY_CHROMATICITIES, 319),
424            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT, 513),
425            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH, 514),
426            new ExifTag(TAG_Y_CB_CR_COEFFICIENTS, 529),
427            new ExifTag(TAG_Y_CB_CR_SUB_SAMPLING, 530),
428            new ExifTag(TAG_Y_CB_CR_POSITIONING, 531),
429            new ExifTag(TAG_REFERENCE_BLACK_WHITE, 532),
430            new ExifTag(TAG_COPYRIGHT, 33432),
431            new ExifTag(TAG_EXIF_IFD_POINTER, 34665),
432            new ExifTag(TAG_GPS_INFO_IFD_POINTER, 34853),
433    };
434    // Primary image IFD Exif Private tags (See JEITA CP-3451 Table 15. page 55).
435    private static final ExifTag[] IFD_EXIF_TAGS = new ExifTag[] {
436            new ExifTag(TAG_EXPOSURE_TIME, 33434),
437            new ExifTag(TAG_F_NUMBER, 33437),
438            new ExifTag(TAG_EXPOSURE_PROGRAM, 34850),
439            new ExifTag(TAG_SPECTRAL_SENSITIVITY, 34852),
440            new ExifTag(TAG_ISO, 34855),
441            new ExifTag(TAG_OECF, 34856),
442            new ExifTag(TAG_EXIF_VERSION, 36864),
443            new ExifTag(TAG_DATETIME_ORIGINAL, 36867),
444            new ExifTag(TAG_DATETIME_DIGITIZED, 36868),
445            new ExifTag(TAG_COMPONENTS_CONFIGURATION, 37121),
446            new ExifTag(TAG_COMPRESSED_BITS_PER_PIXEL, 37122),
447            new ExifTag(TAG_SHUTTER_SPEED_VALUE, 37377),
448            new ExifTag(TAG_APERTURE_VALUE, 37378),
449            new ExifTag(TAG_BRIGHTNESS_VALUE, 37379),
450            new ExifTag(TAG_EXPOSURE_BIAS_VALUE, 37380),
451            new ExifTag(TAG_MAX_APERTURE_VALUE, 37381),
452            new ExifTag(TAG_SUBJECT_DISTANCE, 37382),
453            new ExifTag(TAG_METERING_MODE, 37383),
454            new ExifTag(TAG_LIGHT_SOURCE, 37384),
455            new ExifTag(TAG_FLASH, 37385),
456            new ExifTag(TAG_FOCAL_LENGTH, 37386),
457            new ExifTag(TAG_SUBJECT_AREA, 37396),
458            new ExifTag(TAG_MAKER_NOTE, 37500),
459            new ExifTag(TAG_USER_COMMENT, 37510),
460            new ExifTag(TAG_SUBSEC_TIME, 37520),
461            new ExifTag(TAG_SUBSEC_TIME_ORIG, 37521),
462            new ExifTag(TAG_SUBSEC_TIME_DIG, 37522),
463            new ExifTag(TAG_FLASHPIX_VERSION, 40960),
464            new ExifTag(TAG_COLOR_SPACE, 40961),
465            new ExifTag(TAG_PIXEL_X_DIMENSION, 40962),
466            new ExifTag(TAG_PIXEL_Y_DIMENSION, 40963),
467            new ExifTag(TAG_RELATED_SOUND_FILE, 40964),
468            new ExifTag(TAG_INTEROPERABILITY_IFD_POINTER, 40965),
469            new ExifTag(TAG_FLASH_ENERGY, 41483),
470            new ExifTag(TAG_SPATIAL_FREQUENCY_RESPONSE, 41484),
471            new ExifTag(TAG_FOCAL_PLANE_X_RESOLUTION, 41486),
472            new ExifTag(TAG_FOCAL_PLANE_Y_RESOLUTION, 41487),
473            new ExifTag(TAG_FOCAL_PLANE_RESOLUTION_UNIT, 41488),
474            new ExifTag(TAG_SUBJECT_LOCATION, 41492),
475            new ExifTag(TAG_EXPOSURE_INDEX, 41493),
476            new ExifTag(TAG_SENSING_METHOD, 41495),
477            new ExifTag(TAG_FILE_SOURCE, 41728),
478            new ExifTag(TAG_SCENE_TYPE, 41729),
479            new ExifTag(TAG_CFA_PATTERN, 41730),
480            new ExifTag(TAG_CUSTOM_RENDERED, 41985),
481            new ExifTag(TAG_EXPOSURE_MODE, 41986),
482            new ExifTag(TAG_WHITE_BALANCE, 41987),
483            new ExifTag(TAG_DIGITAL_ZOOM_RATIO, 41988),
484            new ExifTag(TAG_FOCAL_LENGTH_IN_35MM_FILM, 41989),
485            new ExifTag(TAG_SCENE_CAPTURE_TYPE, 41990),
486            new ExifTag(TAG_GAIN_CONTROL, 41991),
487            new ExifTag(TAG_CONTRAST, 41992),
488            new ExifTag(TAG_SATURATION, 41993),
489            new ExifTag(TAG_SHARPNESS, 41994),
490            new ExifTag(TAG_DEVICE_SETTING_DESCRIPTION, 41995),
491            new ExifTag(TAG_SUBJECT_DISTANCE_RANGE, 41996),
492            new ExifTag(TAG_IMAGE_UNIQUE_ID, 42016),
493    };
494    // Primary image IFD GPS Info tags (See JEITA CP-3451 Table 16. page 56).
495    private static final ExifTag[] IFD_GPS_TAGS = new ExifTag[] {
496            new ExifTag(TAG_GPS_VERSION_ID, 0),
497            new ExifTag(TAG_GPS_LATITUDE_REF, 1),
498            new ExifTag(TAG_GPS_LATITUDE, 2),
499            new ExifTag(TAG_GPS_LONGITUDE_REF, 3),
500            new ExifTag(TAG_GPS_LONGITUDE, 4),
501            new ExifTag(TAG_GPS_ALTITUDE_REF, 5),
502            new ExifTag(TAG_GPS_ALTITUDE, 6),
503            new ExifTag(TAG_GPS_TIMESTAMP, 7),
504            new ExifTag(TAG_GPS_SATELLITES, 8),
505            new ExifTag(TAG_GPS_STATUS, 9),
506            new ExifTag(TAG_GPS_MEASURE_MODE, 10),
507            new ExifTag(TAG_GPS_DOP, 11),
508            new ExifTag(TAG_GPS_SPEED_REF, 12),
509            new ExifTag(TAG_GPS_SPEED, 13),
510            new ExifTag(TAG_GPS_TRACK_REF, 14),
511            new ExifTag(TAG_GPS_TRACK, 15),
512            new ExifTag(TAG_GPS_IMG_DIRECTION_REF, 16),
513            new ExifTag(TAG_GPS_IMG_DIRECTION, 17),
514            new ExifTag(TAG_GPS_MAP_DATUM, 18),
515            new ExifTag(TAG_GPS_DEST_LATITUDE_REF, 19),
516            new ExifTag(TAG_GPS_DEST_LATITUDE, 20),
517            new ExifTag(TAG_GPS_DEST_LONGITUDE_REF, 21),
518            new ExifTag(TAG_GPS_DEST_LONGITUDE, 22),
519            new ExifTag(TAG_GPS_DEST_BEARING_REF, 23),
520            new ExifTag(TAG_GPS_DEST_BEARING, 24),
521            new ExifTag(TAG_GPS_DEST_DISTANCE_REF, 25),
522            new ExifTag(TAG_GPS_DEST_DISTANCE, 26),
523            new ExifTag(TAG_GPS_PROCESSING_METHOD, 27),
524            new ExifTag(TAG_GPS_AREA_INFORMATION, 28),
525            new ExifTag(TAG_GPS_DATESTAMP, 29),
526            new ExifTag(TAG_GPS_DIFFERENTIAL, 30),
527    };
528    // Primary image IFD Interoperability tag (See JEITA CP-3451 Table 17. page 56).
529    private static final ExifTag[] IFD_INTEROPERABILITY_TAGS = new ExifTag[] {
530            new ExifTag(TAG_INTEROPERABILITY_INDEX, 1),
531    };
532    // IFD Thumbnail tags (See JEITA CP-3451 Table 18. page 57).
533    private static final ExifTag[] IFD_THUMBNAIL_TAGS = new ExifTag[] {
534            new ExifTag(TAG_THUMBNAIL_IMAGE_WIDTH, 256),
535            new ExifTag(TAG_THUMBNAIL_IMAGE_LENGTH, 257),
536            new ExifTag(TAG_BITS_PER_SAMPLE, 258),
537            new ExifTag(TAG_COMPRESSION, 259),
538            new ExifTag(TAG_PHOTOMETRIC_INTERPRETATION, 262),
539            new ExifTag(TAG_IMAGE_DESCRIPTION, 270),
540            new ExifTag(TAG_MAKE, 271),
541            new ExifTag(TAG_MODEL, 272),
542            new ExifTag(TAG_STRIP_OFFSETS, 273),
543            new ExifTag(TAG_ORIENTATION, 274),
544            new ExifTag(TAG_SAMPLES_PER_PIXEL, 277),
545            new ExifTag(TAG_ROWS_PER_STRIP, 278),
546            new ExifTag(TAG_STRIP_BYTE_COUNTS, 279),
547            new ExifTag(TAG_X_RESOLUTION, 282),
548            new ExifTag(TAG_Y_RESOLUTION, 283),
549            new ExifTag(TAG_PLANAR_CONFIGURATION, 284),
550            new ExifTag(TAG_RESOLUTION_UNIT, 296),
551            new ExifTag(TAG_TRANSFER_FUNCTION, 301),
552            new ExifTag(TAG_SOFTWARE, 305),
553            new ExifTag(TAG_DATETIME, 306),
554            new ExifTag(TAG_ARTIST, 315),
555            new ExifTag(TAG_WHITE_POINT, 318),
556            new ExifTag(TAG_PRIMARY_CHROMATICITIES, 319),
557            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT, 513),
558            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH, 514),
559            new ExifTag(TAG_Y_CB_CR_COEFFICIENTS, 529),
560            new ExifTag(TAG_Y_CB_CR_SUB_SAMPLING, 530),
561            new ExifTag(TAG_Y_CB_CR_POSITIONING, 531),
562            new ExifTag(TAG_REFERENCE_BLACK_WHITE, 532),
563            new ExifTag(TAG_COPYRIGHT, 33432),
564            new ExifTag(TAG_EXIF_IFD_POINTER, 34665),
565            new ExifTag(TAG_GPS_INFO_IFD_POINTER, 34853),
566    };
567
568    // See JEITA CP-3451 Figure 5. page 9.
569    // The following values are used for indicating pointers to the other Image File Directorys.
570
571    // Indices of Exif Ifd tag groups
572    private static final int IFD_TIFF_HINT = 0;
573    private static final int IFD_EXIF_HINT = 1;
574    private static final int IFD_GPS_HINT = 2;
575    private static final int IFD_INTEROPERABILITY_HINT = 3;
576    private static final int IFD_THUMBNAIL_HINT = 4;
577    // List of Exif tag groups
578    private static final ExifTag[][] EXIF_TAGS = new ExifTag[][] {
579            IFD_TIFF_TAGS, IFD_EXIF_TAGS, IFD_GPS_TAGS, IFD_INTEROPERABILITY_TAGS,
580            IFD_THUMBNAIL_TAGS
581    };
582    // List of tags for pointing to the other image file directory offset.
583    private static final ExifTag[] IFD_POINTER_TAGS = new ExifTag[] {
584            new ExifTag(TAG_EXIF_IFD_POINTER, 34665),
585            new ExifTag(TAG_GPS_INFO_IFD_POINTER, 34853),
586            new ExifTag(TAG_INTEROPERABILITY_IFD_POINTER, 40965),
587    };
588    // List of indices of the indicated tag groups according to the IFD_POINTER_TAGS
589    private static final int[] IFD_POINTER_TAG_HINTS = new int[] {
590            IFD_EXIF_HINT, IFD_GPS_HINT, IFD_INTEROPERABILITY_HINT
591    };
592    // Tags for indicating the thumbnail offset and length
593    private static final ExifTag JPEG_INTERCHANGE_FORMAT_TAG =
594            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT, 513);
595    private static final ExifTag JPEG_INTERCHANGE_FORMAT_LENGTH_TAG =
596            new ExifTag(TAG_JPEG_INTERCHANGE_FORMAT_LENGTH, 514);
597
598    // Mappings from tag number to tag name and each item represents one IFD tag group.
599    private static final HashMap[] sExifTagMapsForReading = new HashMap[EXIF_TAGS.length];
600    // Mappings from tag name to tag number and each item represents one IFD tag group.
601    private static final HashMap[] sExifTagMapsForWriting = new HashMap[EXIF_TAGS.length];
602
603    // See JPEG File Interchange Format Version 1.02.
604    // The following values are defined for handling JPEG streams. In this implementation, we are
605    // not only getting information from EXIF but also from some JPEG special segments such as
606    // MARKER_COM for user comment and MARKER_SOFx for image width and height.
607
608    // Identifier for APP1 segment in JPEG
609    private static final byte[] IDENTIFIER_APP1 = "Exif\0\0".getBytes(Charset.forName("US-ASCII"));
610    // JPEG segment markers, that each marker consumes two bytes beginning with 0xff and ending with
611    // the indicator. There is no SOF4, SOF8, SOF16 markers in JPEG and SOFx markers indicates start
612    // of frame(baseline DCT) and the image size info exists in its beginning part.
613    private static final byte MARKER = (byte) 0xff;
614    private static final byte MARKER_SOI = (byte) 0xd8;
615    private static final byte MARKER_SOF0 = (byte) 0xc0;
616    private static final byte MARKER_SOF1 = (byte) 0xc1;
617    private static final byte MARKER_SOF2 = (byte) 0xc2;
618    private static final byte MARKER_SOF3 = (byte) 0xc3;
619    private static final byte MARKER_SOF5 = (byte) 0xc5;
620    private static final byte MARKER_SOF6 = (byte) 0xc6;
621    private static final byte MARKER_SOF7 = (byte) 0xc7;
622    private static final byte MARKER_SOF9 = (byte) 0xc9;
623    private static final byte MARKER_SOF10 = (byte) 0xca;
624    private static final byte MARKER_SOF11 = (byte) 0xcb;
625    private static final byte MARKER_SOF13 = (byte) 0xcd;
626    private static final byte MARKER_SOF14 = (byte) 0xce;
627    private static final byte MARKER_SOF15 = (byte) 0xcf;
628    private static final byte MARKER_SOS = (byte) 0xda;
629    private static final byte MARKER_APP1 = (byte) 0xe1;
630    private static final byte MARKER_COM = (byte) 0xfe;
631    private static final byte MARKER_EOI = (byte) 0xd9;
632
633    static {
634        System.loadLibrary("media_jni");
635        nativeInitRaw();
636        sFormatter = new SimpleDateFormat("yyyy:MM:dd HH:mm:ss");
637        sFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));
638
639        // Build up the hash tables to look up Exif tags for reading Exif tags.
640        for (int hint = 0; hint < EXIF_TAGS.length; ++hint) {
641            sExifTagMapsForReading[hint] = new HashMap();
642            sExifTagMapsForWriting[hint] = new HashMap();
643            for (ExifTag tag : EXIF_TAGS[hint]) {
644                sExifTagMapsForReading[hint].put(tag.number, tag.name);
645                sExifTagMapsForWriting[hint].put(tag.name, tag.number);
646            }
647        }
648    }
649
650    private final String mFilename;
651    private final FileDescriptor mSeekableFileDescriptor;
652    private final AssetManager.AssetInputStream mAssetInputStream;
653    private boolean mIsRaw;
654    private final HashMap[] mAttributes = new HashMap[EXIF_TAGS.length];
655    private boolean mHasThumbnail;
656    // The following values used for indicating a thumbnail position.
657    private int mThumbnailOffset;
658    private int mThumbnailLength;
659    private byte[] mThumbnailBytes;
660
661    // Pattern to check non zero timestamp
662    private static final Pattern sNonZeroTimePattern = Pattern.compile(".*[1-9].*");
663
664    /**
665     * Reads Exif tags from the specified image file.
666     */
667    public ExifInterface(String filename) throws IOException {
668        if (filename == null) {
669            throw new IllegalArgumentException("filename cannot be null");
670        }
671        FileInputStream in = new FileInputStream(filename);
672        mAssetInputStream = null;
673        mFilename = filename;
674        if (isSeekableFD(in.getFD())) {
675            mSeekableFileDescriptor = in.getFD();
676        } else {
677            mSeekableFileDescriptor = null;
678        }
679        loadAttributes(in);
680    }
681
682    /**
683     * Reads Exif tags from the specified image file descriptor. Attribute mutation is supported
684     * for seekable file descriptors only.
685     */
686    public ExifInterface(FileDescriptor fileDescriptor) throws IOException {
687        if (fileDescriptor == null) {
688            throw new IllegalArgumentException("parcelFileDescriptor cannot be null");
689        }
690        mAssetInputStream = null;
691        mFilename = null;
692        if (isSeekableFD(fileDescriptor)) {
693            mSeekableFileDescriptor = fileDescriptor;
694        } else {
695            mSeekableFileDescriptor = null;
696        }
697        loadAttributes(new FileInputStream(fileDescriptor));
698    }
699
700    /**
701     * Reads Exif tags from the specified image input stream. Attribute mutation is not supported
702     * for input streams.
703     */
704    public ExifInterface(InputStream inputStream) throws IOException {
705        if (inputStream == null) {
706            throw new IllegalArgumentException("inputStream cannot be null");
707        }
708        mFilename = null;
709        if (inputStream instanceof AssetManager.AssetInputStream) {
710            mAssetInputStream = (AssetManager.AssetInputStream) inputStream;
711            mSeekableFileDescriptor = null;
712        } else if (inputStream instanceof FileInputStream
713                && isSeekableFD(((FileInputStream) inputStream).getFD())) {
714            mAssetInputStream = null;
715            mSeekableFileDescriptor = ((FileInputStream) inputStream).getFD();
716        } else {
717            mAssetInputStream = null;
718            mSeekableFileDescriptor = null;
719        }
720        loadAttributes(inputStream);
721    }
722
723    /**
724     * Returns the value of the specified tag or {@code null} if there
725     * is no such tag in the image file.
726     *
727     * @param tag the name of the tag.
728     */
729    public String getAttribute(String tag) {
730        // Retrieves all tag groups. The value from primary image tag group has a higher priority
731        // than the value from the thumbnail tag group if there are more than one candidates.
732        for (int i = 0; i < EXIF_TAGS.length; ++i) {
733            Object value = mAttributes[i].get(tag);
734            if (value != null) {
735                return (String) value;
736            }
737        }
738        return null;
739    }
740
741    /**
742     * Returns the integer value of the specified tag. If there is no such tag
743     * in the image file or the value cannot be parsed as integer, return
744     * <var>defaultValue</var>.
745     *
746     * @param tag the name of the tag.
747     * @param defaultValue the value to return if the tag is not available.
748     */
749    public int getAttributeInt(String tag, int defaultValue) {
750        String value = getAttribute(tag);
751        if (value == null) return defaultValue;
752        try {
753            return Integer.valueOf(value);
754        } catch (NumberFormatException e) {
755            return defaultValue;
756        }
757    }
758
759    /**
760     * Returns the double value of the tag that is specified as rational or contains a
761     * double-formatted value. If there is no such tag in the image file or the value cannot be
762     * parsed as double, return <var>defaultValue</var>.
763     *
764     * @param tag the name of the tag.
765     * @param defaultValue the value to return if the tag is not available.
766     */
767    public double getAttributeDouble(String tag, double defaultValue) {
768        String value = getAttribute(tag);
769        if (value == null) return defaultValue;
770        try {
771            int index = value.indexOf("/");
772            if (index == -1) return Double.parseDouble(value);
773            double denom = Double.parseDouble(value.substring(index + 1));
774            if (denom == 0) return defaultValue;
775            double num = Double.parseDouble(value.substring(0, index));
776            return num / denom;
777        } catch (NumberFormatException e) {
778            return defaultValue;
779        }
780    }
781
782    /**
783     * Set the value of the specified tag.
784     *
785     * @param tag the name of the tag.
786     * @param value the value of the tag.
787     */
788    public void setAttribute(String tag, String value) {
789        for (int i = 0 ; i < EXIF_TAGS.length; ++i) {
790            if (sExifTagMapsForWriting[i].containsKey(tag)) {
791                mAttributes[i].put(tag, value);
792            }
793        }
794    }
795
796    /**
797     * This function decides which parser to read the image data according to the given input stream
798     * type and the content of the input stream. In each case, it reads the first three bytes to
799     * determine whether the image data format is JPEG or not.
800     */
801    private void loadAttributes(@NonNull InputStream in) throws IOException {
802        // Initialize mAttributes.
803        for (int i = 0; i < EXIF_TAGS.length; ++i) {
804            mAttributes[i] = new HashMap();
805        }
806
807        // Process RAW input stream
808        if (mAssetInputStream != null) {
809            long asset = mAssetInputStream.getNativeAsset();
810            if (handleRawResult(nativeGetRawAttributesFromAsset(asset))) {
811                return;
812            }
813        } else if (mSeekableFileDescriptor != null) {
814            if (handleRawResult(nativeGetRawAttributesFromFileDescriptor(
815                    mSeekableFileDescriptor))) {
816                return;
817            }
818        } else {
819            in = new BufferedInputStream(in, JPEG_SIGNATURE_SIZE);
820            if (!isJpegInputStream((BufferedInputStream) in) && handleRawResult(
821                    nativeGetRawAttributesFromInputStream(in))) {
822                return;
823            }
824        }
825
826        // Process JPEG input stream
827        try {
828            getJpegAttributes(in);
829        } catch (IOException e) {
830            // Ignore exceptions in order to keep the compatibility with the old versions of
831            // ExifInterface.
832            Log.w(TAG, "Invalid JPEG", e);
833        }
834
835        if (DEBUG) {
836            printAttributes();
837        }
838    }
839
840    private static boolean isJpegInputStream(BufferedInputStream in) throws IOException {
841        in.mark(JPEG_SIGNATURE_SIZE);
842        byte[] signatureBytes = new byte[JPEG_SIGNATURE_SIZE];
843        if (in.read(signatureBytes) != JPEG_SIGNATURE_SIZE) {
844            throw new EOFException();
845        }
846        boolean isJpeg = Arrays.equals(JPEG_SIGNATURE, signatureBytes);
847        in.reset();
848        return isJpeg;
849    }
850
851    private boolean handleRawResult(HashMap map) {
852        if (map == null) {
853            return false;
854        }
855
856        // Mark for disabling the save feature.
857        mIsRaw = true;
858
859        for (Map.Entry entry : (Set<Map.Entry>) map.entrySet()) {
860            String attrName = (String) entry.getKey();
861
862            switch (attrName) {
863                case TAG_HAS_THUMBNAIL:
864                    mHasThumbnail = ((String) entry.getValue()).equalsIgnoreCase("true");
865                    break;
866                case TAG_THUMBNAIL_OFFSET:
867                    mThumbnailOffset = Integer.parseInt((String) entry.getValue());
868                    break;
869                case TAG_THUMBNAIL_LENGTH:
870                    mThumbnailLength = Integer.parseInt((String) entry.getValue());
871                    break;
872                case TAG_THUMBNAIL_DATA:
873                    mThumbnailBytes = (byte[]) entry.getValue();
874                    break;
875                default:
876                    setAttribute(attrName, (String) entry.getValue());
877                    break;
878            }
879        }
880
881        if (DEBUG) {
882            printAttributes();
883        }
884        return true;
885    }
886
887    private static boolean isSeekableFD(FileDescriptor fd) throws IOException {
888        try {
889            Os.lseek(fd, 0, OsConstants.SEEK_CUR);
890            return true;
891        } catch (ErrnoException e) {
892            return false;
893        }
894    }
895
896    // Prints out attributes for debugging.
897    private void printAttributes() {
898        for (int i = 0; i < mAttributes.length; ++i) {
899            Log.d(TAG, "The size of tag group[" + i + "]: " + mAttributes[i].size());
900            for (Map.Entry entry : (Set<Map.Entry>) mAttributes[i].entrySet()) {
901                Log.d(TAG, "tagName: " + entry.getKey() + ", tagValue: " + entry.getValue());
902            }
903        }
904    }
905
906    /**
907     * Save the tag data into the original image file. This is expensive because it involves
908     * copying all the data from one file to another and deleting the old file and renaming the
909     * other. It's best to use{@link #setAttribute(String,String)} to set all attributes to write
910     * and make a single call rather than multiple calls for each attribute.
911     */
912    public void saveAttributes() throws IOException {
913        if (mIsRaw) {
914            throw new UnsupportedOperationException(
915                    "ExifInterface does not support saving attributes on RAW formats.");
916        }
917        if (mSeekableFileDescriptor == null && mFilename == null) {
918            throw new UnsupportedOperationException(
919                    "ExifInterface does not support saving attributes for the current input.");
920        }
921
922        // Keep the thumbnail in memory
923        mThumbnailBytes = getThumbnail();
924
925        FileInputStream in = null;
926        FileOutputStream out = null;
927        File tempFile = null;
928        try {
929            // Move the original file to temporary file.
930            if (mFilename != null) {
931                tempFile = new File(mFilename + ".tmp");
932                File originalFile = new File(mFilename);
933                if (!originalFile.renameTo(tempFile)) {
934                    throw new IOException("Could'nt rename to " + tempFile.getAbsolutePath());
935                }
936            } else if (mSeekableFileDescriptor != null) {
937                tempFile = File.createTempFile("temp", "jpg");
938                Os.lseek(mSeekableFileDescriptor, 0, OsConstants.SEEK_SET);
939                in = new FileInputStream(mSeekableFileDescriptor);
940                out = new FileOutputStream(tempFile);
941                Streams.copy(in, out);
942            }
943        } catch (ErrnoException e) {
944            e.rethrowAsIOException();
945        } finally {
946            IoUtils.closeQuietly(in);
947            IoUtils.closeQuietly(out);
948        }
949
950        in = null;
951        out = null;
952        try {
953            // Save the new file.
954            in = new FileInputStream(tempFile);
955            if (mFilename != null) {
956                out = new FileOutputStream(mFilename);
957            } else if (mSeekableFileDescriptor != null) {
958                Os.lseek(mSeekableFileDescriptor, 0, OsConstants.SEEK_SET);
959                out = new FileOutputStream(mSeekableFileDescriptor);
960            }
961            saveJpegAttributes(in, out);
962        } catch (ErrnoException e) {
963            e.rethrowAsIOException();
964        } finally {
965            IoUtils.closeQuietly(in);
966            IoUtils.closeQuietly(out);
967            tempFile.delete();
968        }
969
970        // Discard the thumbnail in memory
971        mThumbnailBytes = null;
972    }
973
974    /**
975     * Returns true if the image file has a thumbnail.
976     */
977    public boolean hasThumbnail() {
978        return mHasThumbnail;
979    }
980
981    /**
982     * Returns the thumbnail inside the image file, or {@code null} if there is no thumbnail.
983     * The returned data is in JPEG format and can be decoded using
984     * {@link android.graphics.BitmapFactory#decodeByteArray(byte[],int,int)}
985     */
986    public byte[] getThumbnail() {
987        if (!mHasThumbnail) {
988            return null;
989        }
990        if (mThumbnailBytes != null) {
991            return mThumbnailBytes;
992        }
993
994        // Read the thumbnail.
995        FileInputStream in = null;
996        try {
997            if (mAssetInputStream != null) {
998                return nativeGetThumbnailFromAsset(
999                        mAssetInputStream.getNativeAsset(), mThumbnailOffset, mThumbnailLength);
1000            } else if (mFilename != null) {
1001                in = new FileInputStream(mFilename);
1002            } else if (mSeekableFileDescriptor != null) {
1003                Os.lseek(mSeekableFileDescriptor, 0, OsConstants.SEEK_SET);
1004                in = new FileInputStream(mSeekableFileDescriptor);
1005            }
1006            if (in == null) {
1007                // Should not be reached this.
1008                throw new FileNotFoundException();
1009            }
1010            if (in.skip(mThumbnailOffset) != mThumbnailOffset) {
1011                throw new IOException("Corrupted image");
1012            }
1013            byte[] buffer = new byte[mThumbnailLength];
1014            if (in.read(buffer) != mThumbnailLength) {
1015                throw new IOException("Corrupted image");
1016            }
1017            return buffer;
1018        } catch (IOException | ErrnoException e) {
1019            // Couldn't get a thumbnail image.
1020        } finally {
1021            IoUtils.closeQuietly(in);
1022        }
1023        return null;
1024    }
1025
1026    /**
1027     * Returns the offset and length of thumbnail inside the image file, or
1028     * {@code null} if there is no thumbnail.
1029     *
1030     * @return two-element array, the offset in the first value, and length in
1031     *         the second, or {@code null} if no thumbnail was found.
1032     * @hide
1033     */
1034    public long[] getThumbnailRange() {
1035        long[] range = new long[2];
1036        range[0] = mThumbnailOffset;
1037        range[1] = mThumbnailLength;
1038        return range;
1039    }
1040
1041    /**
1042     * Stores the latitude and longitude value in a float array. The first element is
1043     * the latitude, and the second element is the longitude. Returns false if the
1044     * Exif tags are not available.
1045     */
1046    public boolean getLatLong(float output[]) {
1047        String latValue = getAttribute(TAG_GPS_LATITUDE);
1048        String latRef = getAttribute(TAG_GPS_LATITUDE_REF);
1049        String lngValue = getAttribute(TAG_GPS_LONGITUDE);
1050        String lngRef = getAttribute(TAG_GPS_LONGITUDE_REF);
1051
1052        if (latValue != null && latRef != null && lngValue != null && lngRef != null) {
1053            try {
1054                output[0] = convertRationalLatLonToFloat(latValue, latRef);
1055                output[1] = convertRationalLatLonToFloat(lngValue, lngRef);
1056                return true;
1057            } catch (IllegalArgumentException e) {
1058                // if values are not parseable
1059            }
1060        }
1061
1062        return false;
1063    }
1064
1065    /**
1066     * Return the altitude in meters. If the exif tag does not exist, return
1067     * <var>defaultValue</var>.
1068     *
1069     * @param defaultValue the value to return if the tag is not available.
1070     */
1071    public double getAltitude(double defaultValue) {
1072        double altitude = getAttributeDouble(TAG_GPS_ALTITUDE, -1);
1073        int ref = getAttributeInt(TAG_GPS_ALTITUDE_REF, -1);
1074
1075        if (altitude >= 0 && ref >= 0) {
1076            return (altitude * ((ref == 1) ? -1 : 1));
1077        } else {
1078            return defaultValue;
1079        }
1080    }
1081
1082    /**
1083     * Returns number of milliseconds since Jan. 1, 1970, midnight local time.
1084     * Returns -1 if the date time information if not available.
1085     * @hide
1086     */
1087    public long getDateTime() {
1088        String dateTimeString = getAttribute(TAG_DATETIME);
1089        if (dateTimeString == null
1090                || !sNonZeroTimePattern.matcher(dateTimeString).matches()) return -1;
1091
1092        ParsePosition pos = new ParsePosition(0);
1093        try {
1094            // The exif field is in local time. Parsing it as if it is UTC will yield time
1095            // since 1/1/1970 local time
1096            Date datetime = sFormatter.parse(dateTimeString, pos);
1097            if (datetime == null) return -1;
1098            long msecs = datetime.getTime();
1099
1100            String subSecs = getAttribute(TAG_SUBSECTIME);
1101            if (subSecs != null) {
1102                try {
1103                    long sub = Long.valueOf(subSecs);
1104                    while (sub > 1000) {
1105                        sub /= 10;
1106                    }
1107                    msecs += sub;
1108                } catch (NumberFormatException e) {
1109                    // Ignored
1110                }
1111            }
1112            return msecs;
1113        } catch (IllegalArgumentException e) {
1114            return -1;
1115        }
1116    }
1117
1118    /**
1119     * Returns number of milliseconds since Jan. 1, 1970, midnight UTC.
1120     * Returns -1 if the date time information if not available.
1121     * @hide
1122     */
1123    public long getGpsDateTime() {
1124        String date = getAttribute(TAG_GPS_DATESTAMP);
1125        String time = getAttribute(TAG_GPS_TIMESTAMP);
1126        if (date == null || time == null
1127                || (!sNonZeroTimePattern.matcher(date).matches()
1128                && !sNonZeroTimePattern.matcher(time).matches())) return -1;
1129
1130        String dateTimeString = date + ' ' + time;
1131
1132        ParsePosition pos = new ParsePosition(0);
1133        try {
1134            Date datetime = sFormatter.parse(dateTimeString, pos);
1135            if (datetime == null) return -1;
1136            return datetime.getTime();
1137        } catch (IllegalArgumentException e) {
1138            return -1;
1139        }
1140    }
1141
1142    private static float convertRationalLatLonToFloat(String rationalString, String ref) {
1143        try {
1144            String [] parts = rationalString.split(",");
1145
1146            String [] pair;
1147            pair = parts[0].split("/");
1148            double degrees = Double.parseDouble(pair[0].trim())
1149                    / Double.parseDouble(pair[1].trim());
1150
1151            pair = parts[1].split("/");
1152            double minutes = Double.parseDouble(pair[0].trim())
1153                    / Double.parseDouble(pair[1].trim());
1154
1155            pair = parts[2].split("/");
1156            double seconds = Double.parseDouble(pair[0].trim())
1157                    / Double.parseDouble(pair[1].trim());
1158
1159            double result = degrees + (minutes / 60.0) + (seconds / 3600.0);
1160            if ((ref.equals("S") || ref.equals("W"))) {
1161                return (float) -result;
1162            }
1163            return (float) result;
1164        } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
1165            // Not valid
1166            throw new IllegalArgumentException();
1167        }
1168    }
1169
1170    // Loads EXIF attributes from a JPEG input stream.
1171    private void getJpegAttributes(InputStream inputStream) throws IOException {
1172        // See JPEG File Interchange Format Specification page 5.
1173        if (DEBUG) {
1174            Log.d(TAG, "getJpegAttributes starting with: " + inputStream);
1175        }
1176        DataInputStream dataInputStream = new DataInputStream(inputStream);
1177        byte marker;
1178        int bytesRead = 0;
1179        ++bytesRead;
1180        if ((marker = dataInputStream.readByte()) != MARKER) {
1181            throw new IOException("Invalid marker: " + Integer.toHexString(marker & 0xff));
1182        }
1183        ++bytesRead;
1184        if (dataInputStream.readByte() != MARKER_SOI) {
1185            throw new IOException("Invalid marker: " + Integer.toHexString(marker & 0xff));
1186        }
1187        while (true) {
1188            ++bytesRead;
1189            marker = dataInputStream.readByte();
1190            if (marker != MARKER) {
1191                throw new IOException("Invalid marker:" + Integer.toHexString(marker & 0xff));
1192            }
1193            ++bytesRead;
1194            marker = dataInputStream.readByte();
1195            if (DEBUG) {
1196                Log.d(TAG, "Found JPEG segment indicator: " + Integer.toHexString(marker & 0xff));
1197            }
1198
1199            // EOI indicates the end of an image and in case of SOS, JPEG image stream starts and
1200            // the image data will terminate right after.
1201            if (marker == MARKER_EOI || marker == MARKER_SOS) {
1202                break;
1203            }
1204            bytesRead += 2;
1205            int length = dataInputStream.readUnsignedShort() - 2;
1206            if (length < 0) {
1207                throw new IOException("Invalid length");
1208            }
1209            bytesRead += length;
1210            switch (marker) {
1211                case MARKER_APP1: {
1212                    if (DEBUG) {
1213                        Log.d(TAG, "MARKER_APP1");
1214                    }
1215                    bytesRead -= length;
1216                    if (length < 6) {
1217                        throw new IOException("Invalid exif");
1218                    }
1219                    byte[] identifier = new byte[6];
1220                    if (inputStream.read(identifier) != 6) {
1221                        throw new IOException("Invalid exif");
1222                    }
1223                    if (!Arrays.equals(identifier, IDENTIFIER_APP1)) {
1224                        throw new IOException("Invalid app1 identifier");
1225                    }
1226                    bytesRead += 6;
1227                    length -= 6;
1228                    if (length <= 0) {
1229                        throw new IOException("Invalid exif");
1230                    }
1231                    if (DEBUG) {
1232                        Log.d(TAG, "readExifSegment with a byte array (length: " + length + ")");
1233                    }
1234                    byte[] bytes = new byte[length];
1235                    if (dataInputStream.read(bytes) != length) {
1236                        throw new IOException("Invalid exif");
1237                    }
1238                    readExifSegment(bytes, bytesRead);
1239                    bytesRead += length;
1240                    length = 0;
1241                    break;
1242                }
1243
1244                case MARKER_COM: {
1245                    byte[] bytes = new byte[length];
1246                    if (dataInputStream.read(bytes) != length) {
1247                        throw new IOException("Invalid exif");
1248                    }
1249                    setAttribute("UserComment", new String(bytes, Charset.forName("US-ASCII")));
1250                    break;
1251                }
1252
1253                case MARKER_SOF0:
1254                case MARKER_SOF1:
1255                case MARKER_SOF2:
1256                case MARKER_SOF3:
1257                case MARKER_SOF5:
1258                case MARKER_SOF6:
1259                case MARKER_SOF7:
1260                case MARKER_SOF9:
1261                case MARKER_SOF10:
1262                case MARKER_SOF11:
1263                case MARKER_SOF13:
1264                case MARKER_SOF14:
1265                case MARKER_SOF15: {
1266                    dataInputStream.skipBytes(1);
1267                    setAttribute("ImageLength",
1268                            String.valueOf(dataInputStream.readUnsignedShort()));
1269                    setAttribute("ImageWidth", String.valueOf(dataInputStream.readUnsignedShort()));
1270                    length -= 5;
1271                    break;
1272                }
1273
1274                default: {
1275                    break;
1276                }
1277            }
1278            if (length < 0) {
1279                throw new IOException("Invalid length");
1280            }
1281            dataInputStream.skipBytes(length);
1282        }
1283    }
1284
1285    // Stores a new JPEG image with EXIF attributes into a given output stream.
1286    private void saveJpegAttributes(InputStream inputStream, OutputStream outputStream)
1287            throws IOException {
1288        // See JPEG File Interchange Format Specification page 5.
1289        if (DEBUG) {
1290            Log.d(TAG, "saveJpegAttributes starting with (inputStream: " + inputStream
1291                    + ", outputStream: " + outputStream + ")");
1292        }
1293        DataInputStream dataInputStream = new DataInputStream(inputStream);
1294        ExifDataOutputStream dataOutputStream = new ExifDataOutputStream(outputStream);
1295        int bytesRead = 0;
1296        ++bytesRead;
1297        if (dataInputStream.readByte() != MARKER) {
1298            throw new IOException("Invalid marker");
1299        }
1300        dataOutputStream.writeByte(MARKER);
1301        ++bytesRead;
1302        if (dataInputStream.readByte() != MARKER_SOI) {
1303            throw new IOException("Invalid marker");
1304        }
1305        dataOutputStream.writeByte(MARKER_SOI);
1306
1307        byte[] bytes = new byte[4096];
1308
1309        while (true) {
1310            ++bytesRead;
1311            if (dataInputStream.readByte() != MARKER) {
1312                throw new IOException("Invalid marker");
1313            }
1314            dataOutputStream.writeByte(MARKER);
1315            ++bytesRead;
1316            byte marker = dataInputStream.readByte();
1317            dataOutputStream.writeByte(marker);
1318            switch (marker) {
1319                case MARKER_APP1: {
1320                    // Rewrite EXIF segment
1321                    int length = dataInputStream.readUnsignedShort() - 2;
1322                    if (length < 0) {
1323                        throw new IOException("Invalid length");
1324                    }
1325                    bytesRead += 2;
1326                    int read;
1327                    while ((read = dataInputStream.read(
1328                            bytes, 0, Math.min(length, bytes.length))) > 0) {
1329                        length -= read;
1330                    }
1331                    bytesRead += length;
1332                    writeExifSegment(dataOutputStream, bytesRead);
1333                    break;
1334                }
1335                case MARKER_EOI:
1336                case MARKER_SOS: {
1337                    // Copy all the remaining data
1338                    Streams.copy(dataInputStream, dataOutputStream);
1339                    return;
1340                }
1341                default: {
1342                    // Copy JPEG segment
1343                    int length = dataInputStream.readUnsignedShort();
1344                    dataOutputStream.writeUnsignedShort(length);
1345                    if (length < 0) {
1346                        throw new IOException("Invalid length");
1347                    }
1348                    length -= 2;
1349                    bytesRead += 2;
1350                    int read;
1351                    while ((read = dataInputStream.read(
1352                            bytes, 0, Math.min(length, bytes.length))) > 0) {
1353                        dataOutputStream.write(bytes, 0, read);
1354                        length -= read;
1355                    }
1356                    bytesRead += length;
1357                    break;
1358                }
1359            }
1360        }
1361    }
1362
1363    // Reads the given EXIF byte area and save its tag data into attributes.
1364    private void readExifSegment(byte[] exifBytes, int exifOffsetFromBeginning) throws IOException {
1365        // Parse TIFF Headers. See JEITA CP-3451C Table 1. page 10.
1366        ByteOrderAwarenessDataInputStream dataInputStream =
1367                new ByteOrderAwarenessDataInputStream(exifBytes);
1368
1369        // Read byte align
1370        short byteOrder = dataInputStream.readShort();
1371        switch (byteOrder) {
1372            case BYTE_ALIGN_II:
1373                if (DEBUG) {
1374                    Log.d(TAG, "readExifSegment: Byte Align II");
1375                }
1376                dataInputStream.setByteOrder(ByteOrder.LITTLE_ENDIAN);
1377                break;
1378            case BYTE_ALIGN_MM:
1379                if (DEBUG) {
1380                    Log.d(TAG, "readExifSegment: Byte Align MM");
1381                }
1382                dataInputStream.setByteOrder(ByteOrder.BIG_ENDIAN);
1383                break;
1384            default:
1385                throw new IOException("Invalid byte order: " + Integer.toHexString(byteOrder));
1386        }
1387
1388        int startCode = dataInputStream.readUnsignedShort();
1389        if (startCode != 0x2a) {
1390            throw new IOException("Invalid exif start: " + Integer.toHexString(startCode));
1391        }
1392
1393        // Read first ifd offset
1394        long firstIfdOffset = dataInputStream.readUnsignedInt();
1395        if (firstIfdOffset < 8 || firstIfdOffset >= exifBytes.length) {
1396            throw new IOException("Invalid first Ifd offset: " + firstIfdOffset);
1397        }
1398        firstIfdOffset -= 8;
1399        if (firstIfdOffset > 0) {
1400            if (dataInputStream.skip(firstIfdOffset) != firstIfdOffset) {
1401                throw new IOException("Couldn't jump to first Ifd: " + firstIfdOffset);
1402            }
1403        }
1404
1405        // Read primary image TIFF image file directory.
1406        readImageFileDirectory(dataInputStream, IFD_TIFF_HINT);
1407
1408        // Process thumbnail.
1409        String jpegInterchangeFormatString = getAttribute(JPEG_INTERCHANGE_FORMAT_TAG.name);
1410        String jpegInterchangeFormatLengthString =
1411                getAttribute(JPEG_INTERCHANGE_FORMAT_LENGTH_TAG.name);
1412        if (jpegInterchangeFormatString != null && jpegInterchangeFormatLengthString != null) {
1413            try {
1414                int jpegInterchangeFormat = Integer.parseInt(jpegInterchangeFormatString);
1415                int jpegInterchangeFormatLength = Integer
1416                        .parseInt(jpegInterchangeFormatLengthString);
1417                // The following code limits the size of thumbnail size not to overflow EXIF data area.
1418                jpegInterchangeFormatLength = Math.min(jpegInterchangeFormat
1419                        + jpegInterchangeFormatLength, exifOffsetFromBeginning + exifBytes.length)
1420                        - jpegInterchangeFormat;
1421                if (jpegInterchangeFormat > 0 && jpegInterchangeFormatLength > 0) {
1422                    mHasThumbnail = true;
1423                    mThumbnailOffset = exifOffsetFromBeginning + jpegInterchangeFormat;
1424                    mThumbnailLength = jpegInterchangeFormatLength;
1425
1426                    if (mFilename == null && mAssetInputStream == null
1427                            && mSeekableFileDescriptor == null) {
1428                        // Save the thumbnail in memory if the input doesn't support reading again.
1429                        byte[] thumbnailBytes = new byte[jpegInterchangeFormatLength];
1430                        dataInputStream.seek(jpegInterchangeFormat);
1431                        dataInputStream.readFully(thumbnailBytes);
1432                        mThumbnailBytes = thumbnailBytes;
1433
1434                        if (DEBUG) {
1435                            Bitmap bitmap = BitmapFactory.decodeByteArray(
1436                                    thumbnailBytes, 0, thumbnailBytes.length);
1437                            Log.d(TAG, "Thumbnail offset: " + mThumbnailOffset + ", length: "
1438                                    + mThumbnailLength + ", width: " + bitmap.getWidth()
1439                                    + ", height: "
1440                                    + bitmap.getHeight());
1441                        }
1442                    }
1443                }
1444            } catch (NumberFormatException e) {
1445                // Ignored the corrupted image.
1446            }
1447        }
1448
1449        // For compatibility, keep data formats as follows.
1450        convertToInt(TAG_IMAGE_WIDTH);
1451        convertToInt(TAG_IMAGE_LENGTH);
1452        convertToInt(TAG_ORIENTATION);
1453        convertToInt(TAG_FLASH);
1454        convertToRational(TAG_FOCAL_LENGTH);
1455        convertToDouble(TAG_DIGITAL_ZOOM_RATIO);
1456        convertToDouble(TAG_EXPOSURE_TIME);
1457        convertToDouble(TAG_F_NUMBER);
1458        convertToDouble(TAG_SUBJECT_DISTANCE);
1459        convertToInt(TAG_ISO);
1460        convertToDouble(TAG_EXPOSURE_BIAS_VALUE);
1461        convertToInt(TAG_WHITE_BALANCE);
1462        convertToInt(TAG_LIGHT_SOURCE);
1463        convertToInt(TAG_METERING_MODE);
1464        convertToInt(TAG_EXPOSURE_PROGRAM);
1465        convertToInt(TAG_EXPOSURE_MODE);
1466        convertToRational(TAG_GPS_ALTITUDE);
1467        convertToInt(TAG_GPS_ALTITUDE_REF);
1468        convertToRational(TAG_GPS_LONGITUDE);
1469        convertToRational(TAG_GPS_LATITUDE);
1470        convertToTimetamp(TAG_GPS_TIMESTAMP);
1471
1472        // The value of DATETIME tag has the same value of DATETIME_ORIGINAL tag.
1473        String valueOfDateTimeOriginal = getAttribute("DateTimeOriginal");
1474        if (valueOfDateTimeOriginal != null) {
1475            setAttribute(TAG_DATETIME, valueOfDateTimeOriginal);
1476        }
1477
1478        // Add the default value.
1479        if (getAttribute(TAG_IMAGE_WIDTH) == null) {
1480            setAttribute(TAG_IMAGE_WIDTH, "0");
1481        }
1482        if (getAttribute(TAG_IMAGE_LENGTH) == null) {
1483            setAttribute(TAG_IMAGE_LENGTH, "0");
1484        }
1485        if (getAttribute(TAG_ORIENTATION) == null) {
1486            setAttribute(TAG_ORIENTATION, "0");
1487        }
1488        if (getAttribute(TAG_LIGHT_SOURCE) == null) {
1489            setAttribute(TAG_LIGHT_SOURCE, "0");
1490        }
1491    }
1492
1493    // Converts the tag value to timestamp; Otherwise deletes the given tag.
1494    private void convertToTimetamp(String tagName) {
1495        String entryValue = getAttribute(tagName);
1496        if (entryValue == null) return;
1497        int dataFormat = getDataFormatOfExifEntryValue(entryValue);
1498        String[] components = entryValue.split(",");
1499        if (dataFormat == IFD_FORMAT_SRATIONAL && components.length == 3) {
1500            StringBuilder stringBuilder = new StringBuilder();
1501            for (String component : components) {
1502                if (stringBuilder.length() > 0) {
1503                    stringBuilder.append(":");
1504                }
1505                String[] rationalNumber = component.split("/");
1506                int numerator = Integer.parseInt(rationalNumber[0]);
1507                int denominator = Integer.parseInt(rationalNumber[1]);
1508                if (denominator == 0) {
1509                    numerator = 0;
1510                    denominator = 1;
1511                }
1512                int value = numerator / denominator;
1513                stringBuilder.append(String.format("%02d", value));
1514            }
1515            setAttribute(tagName, stringBuilder.toString());
1516        } else if (dataFormat != IFD_FORMAT_STRING) {
1517            setAttribute(tagName, null);
1518        }
1519    }
1520
1521    // Checks the tag value of a given tag formatted in double type; Otherwise try to convert it to
1522    // double type or delete it.
1523    private void convertToDouble(String tagName) {
1524        String entryValue = getAttribute(tagName);
1525        if (entryValue == null) return;
1526        int dataFormat = getDataFormatOfExifEntryValue(entryValue);
1527        switch (dataFormat) {
1528            case IFD_FORMAT_SRATIONAL: {
1529                StringBuilder stringBuilder = new StringBuilder();
1530                String[] components = entryValue.split(",");
1531                for (String component : components) {
1532                    if (stringBuilder.length() > 0) {
1533                        stringBuilder.append(",");
1534                    }
1535                    String[] rationalNumber = component.split("/");
1536                    int numerator = Integer.parseInt(rationalNumber[0]);
1537                    int denominator = Integer.parseInt(rationalNumber[1]);
1538                    if (denominator == 0) {
1539                        numerator = 0;
1540                        denominator = 1;
1541                    }
1542                    stringBuilder.append((double) numerator / denominator);
1543                }
1544                setAttribute(tagName, stringBuilder.toString());
1545                break;
1546            }
1547            case IFD_FORMAT_DOUBLE:
1548                // Keep it as is.
1549                break;
1550            default:
1551                setAttribute(tagName, null);
1552                break;
1553        }
1554    }
1555
1556    // Checks the tag value of a given tag formatted in int type; Otherwise deletes the tag value.
1557    private void convertToRational(String tagName) {
1558        String entryValue = getAttribute(tagName);
1559        if (entryValue == null) return;
1560        int dataFormat = getDataFormatOfExifEntryValue(entryValue);
1561        switch (dataFormat) {
1562            case IFD_FORMAT_SLONG:
1563            case IFD_FORMAT_DOUBLE: {
1564                StringBuilder stringBuilder = new StringBuilder();
1565                String[] components = entryValue.split(",");
1566                for (String component : components) {
1567                    if (stringBuilder.length() > 0) {
1568                        stringBuilder.append(",");
1569                    }
1570                    double doubleValue = Double.parseDouble(component);
1571                    stringBuilder.append((int) (doubleValue * 10000.0)).append("/").append(10000);
1572                }
1573                setAttribute(tagName, stringBuilder.toString());
1574                break;
1575            }
1576            case IFD_FORMAT_SRATIONAL:
1577                // Keep it as is.
1578                break;
1579            default:
1580                setAttribute(tagName, null);
1581                break;
1582        }
1583    }
1584
1585    // Checks the tag value of a given tag formatted in int type; Otherwise deletes the tag value.
1586    private void convertToInt(String tagName) {
1587        String entryValue = getAttribute(tagName);
1588        if (entryValue == null) return;
1589        int dataFormat = getDataFormatOfExifEntryValue(entryValue);
1590        if (dataFormat != IFD_FORMAT_SLONG) {
1591            setAttribute(tagName, null);
1592        }
1593    }
1594
1595    // Reads image file directory, which is a tag group in EXIF.
1596    private void readImageFileDirectory(ByteOrderAwarenessDataInputStream dataInputStream, int hint)
1597            throws IOException {
1598        if (dataInputStream.peek() + 2 > dataInputStream.mLength) {
1599            // Return if there is no data from the offset.
1600            return;
1601        }
1602        // See JEITA CP-3451 Figure 5. page 9.
1603        short numberOfDirectoryEntry = dataInputStream.readShort();
1604        if (dataInputStream.peek() + 12 * numberOfDirectoryEntry > dataInputStream.mLength) {
1605            // Return if the size of entries is too big.
1606            return;
1607        }
1608
1609        if (DEBUG) {
1610            Log.d(TAG, "numberOfDirectoryEntry: " + numberOfDirectoryEntry);
1611        }
1612
1613        for (short i = 0; i < numberOfDirectoryEntry; ++i) {
1614            int tagNumber = dataInputStream.readUnsignedShort();
1615            int dataFormat = dataInputStream.readUnsignedShort();
1616            int numberOfComponents = dataInputStream.readInt();
1617            long nextEntryOffset = dataInputStream.peek() + 4;  // next four bytes is for data
1618                                                                // offset or value.
1619            // Look up a corresponding tag from tag number
1620            String tagName = (String) sExifTagMapsForReading[hint].get(tagNumber);
1621
1622            if (DEBUG) {
1623                Log.d(TAG, String.format("hint: %d, tagNumber: %d, tagName: %s, dataFormat: %d," +
1624                        "numberOfComponents: %d", hint, tagNumber, tagName, dataFormat,
1625                        numberOfComponents));
1626            }
1627
1628            if (tagName == null || dataFormat <= 0 ||
1629                    dataFormat >= IFD_FORMAT_BYTES_PER_FORMAT.length) {
1630                // Skip if the parsed tag number is not defined or invalid data format.
1631                if (tagName == null) {
1632                    Log.w(TAG, "Skip the tag entry since tag number is not defined: " + tagNumber);
1633                } else {
1634                    Log.w(TAG, "Skip the tag entry since data format is invalid: " + dataFormat);
1635                }
1636                dataInputStream.seek(nextEntryOffset);
1637                continue;
1638            }
1639
1640            // Read a value from data field or seek to the value offset which is stored in data
1641            // field if the size of the entry value is bigger than 4.
1642            int byteCount = numberOfComponents * IFD_FORMAT_BYTES_PER_FORMAT[dataFormat];
1643            if (byteCount > 4) {
1644                long offset = dataInputStream.readUnsignedInt();
1645                if (DEBUG) {
1646                    Log.d(TAG, "seek to data offset: " + offset);
1647                }
1648                if (offset + byteCount <= dataInputStream.mLength) {
1649                    dataInputStream.seek(offset);
1650                } else {
1651                     // Skip if invalid data offset.
1652                    Log.w(TAG, "Skip the tag entry since data offset is invalid: " + offset);
1653                    dataInputStream.seek(nextEntryOffset);
1654                    continue;
1655                }
1656            }
1657
1658            // Recursively parse IFD when a IFD pointer tag appears.
1659            int innerIfdHint = getIfdHintFromTagNumber(tagNumber);
1660            if (DEBUG) {
1661                Log.d(TAG, "innerIfdHint: " + innerIfdHint + " byteCount: " + byteCount);
1662            }
1663            if (innerIfdHint >= 0) {
1664                long offset = -1L;
1665                // Get offset from data field
1666                switch (dataFormat) {
1667                    case IFD_FORMAT_USHORT: {
1668                        offset = dataInputStream.readUnsignedShort();
1669                        break;
1670                    }
1671                    case IFD_FORMAT_SSHORT: {
1672                        offset = dataInputStream.readShort();
1673                        break;
1674                    }
1675                    case IFD_FORMAT_ULONG: {
1676                        offset = dataInputStream.readUnsignedInt();
1677                        break;
1678                    }
1679                    case IFD_FORMAT_SLONG: {
1680                        offset = dataInputStream.readInt();
1681                        break;
1682                    }
1683                    default: {
1684                        // Nothing to do
1685                        break;
1686                    }
1687                }
1688                if (DEBUG) {
1689                    Log.d(TAG, String.format("Offset: %d, tagName: %s", offset, tagName));
1690                }
1691                if (offset > 0L && offset < dataInputStream.mLength) {
1692                    dataInputStream.seek(offset);
1693                    readImageFileDirectory(dataInputStream, innerIfdHint);
1694                } else {
1695                    Log.w(TAG, "Skip jump into the IFD since its offset is invalid: " + offset);
1696                }
1697
1698                dataInputStream.seek(nextEntryOffset);
1699                continue;
1700            }
1701
1702            if (numberOfComponents == 1 || dataFormat == IFD_FORMAT_STRING
1703                    || dataFormat == IFD_FORMAT_UNDEFINED) {
1704                String entryValue = readExifEntryValue(
1705                        dataInputStream, dataFormat, numberOfComponents);
1706                if (entryValue != null) {
1707                    setAttribute(tagName, entryValue);
1708                }
1709            } else {
1710                StringBuilder entryValueBuilder = new StringBuilder();
1711                for (int c = 0; c < numberOfComponents; ++c) {
1712                    if (entryValueBuilder.length() > 0) {
1713                        entryValueBuilder.append(",");
1714                    }
1715                    entryValueBuilder.append(readExifEntryValue(
1716                            dataInputStream, dataFormat, numberOfComponents));
1717                }
1718                setAttribute(tagName, entryValueBuilder.toString());
1719            }
1720
1721            if (dataInputStream.peek() != nextEntryOffset) {
1722                dataInputStream.seek(nextEntryOffset);
1723            }
1724        }
1725
1726        if (dataInputStream.peek() + 4 <= dataInputStream.mLength) {
1727            long nextIfdOffset = dataInputStream.readUnsignedInt();
1728            if (DEBUG) {
1729                Log.d(TAG, String.format("nextIfdOffset: %d", nextIfdOffset));
1730            }
1731            // The next IFD offset needs to be bigger than 8
1732            // since the first IFD offset is at least 8.
1733            if (nextIfdOffset > 8 && nextIfdOffset < dataInputStream.mLength) {
1734                dataInputStream.seek(nextIfdOffset);
1735                readImageFileDirectory(dataInputStream, IFD_THUMBNAIL_HINT);
1736            }
1737        }
1738    }
1739
1740    // Reads a value from where the entry value are stored.
1741    private String readExifEntryValue(ByteOrderAwarenessDataInputStream dataInputStream,
1742            int dataFormat, int numberOfComponents) throws IOException {
1743        // See TIFF 6.0 spec Types. page 15.
1744        switch (dataFormat) {
1745            case IFD_FORMAT_BYTE: {
1746                return String.valueOf(dataInputStream.readByte());
1747            }
1748            case IFD_FORMAT_SBYTE: {
1749                return String.valueOf(dataInputStream.readByte() & 0xff);
1750            }
1751            case IFD_FORMAT_USHORT: {
1752                return String.valueOf(dataInputStream.readUnsignedShort());
1753            }
1754            case IFD_FORMAT_SSHORT: {
1755                return String.valueOf(dataInputStream.readUnsignedInt());
1756            }
1757            case IFD_FORMAT_ULONG: {
1758                return String.valueOf(dataInputStream.readInt());
1759            }
1760            case IFD_FORMAT_SLONG: {
1761                return String.valueOf(dataInputStream.readInt());
1762            }
1763            case IFD_FORMAT_URATIONAL:
1764            case IFD_FORMAT_SRATIONAL: {
1765                int numerator = dataInputStream.readInt();
1766                int denominator = dataInputStream.readInt();
1767                return numerator + "/" + denominator;
1768            }
1769            case IFD_FORMAT_SINGLE: {
1770                return String.valueOf(dataInputStream.readFloat());
1771            }
1772            case IFD_FORMAT_DOUBLE: {
1773                return String.valueOf(dataInputStream.readDouble());
1774            }
1775            case IFD_FORMAT_UNDEFINED:  // Usually UNDEFINED format is ASCII.
1776            case IFD_FORMAT_STRING: {
1777                byte[] bytes = new byte[numberOfComponents];
1778                dataInputStream.readFully(bytes);
1779                int index = 0;
1780                if (numberOfComponents >= EXIF_ASCII_PREFIX.length) {
1781                    boolean same = true;
1782                    for (int i = 0; i < EXIF_ASCII_PREFIX.length; ++i) {
1783                        if (bytes[i] != EXIF_ASCII_PREFIX[i]) {
1784                            same = false;
1785                            break;
1786                        }
1787                    }
1788                    if (same) {
1789                        index = EXIF_ASCII_PREFIX.length;
1790                    }
1791                }
1792
1793                StringBuilder stringBuilder = new StringBuilder();
1794                while (index < numberOfComponents) {
1795                    int ch = bytes[index];
1796                    if (ch == 0) {
1797                        break;
1798                    }
1799                    if (ch >= 32) {
1800                        stringBuilder.append((char) ch);
1801                    }
1802                    else {
1803                        stringBuilder.append('?');
1804                    }
1805                    ++index;
1806                }
1807                return stringBuilder.toString();
1808            }
1809            default: {
1810                // Nothing to do
1811                return null;
1812            }
1813        }
1814    }
1815
1816    // Gets the corresponding IFD group index of the given tag number for writing Exif Tags.
1817    private static int getIfdHintFromTagNumber(int tagNumber) {
1818        for (int i = 0; i < IFD_POINTER_TAG_HINTS.length; ++i) {
1819            if (IFD_POINTER_TAGS[i].number == tagNumber) {
1820                return IFD_POINTER_TAG_HINTS[i];
1821            }
1822        }
1823        return -1;
1824    }
1825
1826    // Writes an Exif segment into the given output stream.
1827    private int writeExifSegment(ExifDataOutputStream dataOutputStream, int exifOffsetFromBeginning)
1828            throws IOException {
1829        // The following variables are for calculating each IFD tag group size in bytes.
1830        int[] ifdOffsets = new int[EXIF_TAGS.length];
1831        int[] ifdDataSizes = new int[EXIF_TAGS.length];
1832
1833        // Remove IFD pointer tags (we'll re-add it later.)
1834        for (ExifTag tag : IFD_POINTER_TAGS) {
1835            setAttribute(tag.name, null);
1836        }
1837
1838        // Add IFD pointer tags. The next offset of primary image TIFF IFD will have thumbnail IFD
1839        // offset when there is one or more tags in the thumbnail IFD.
1840        if (!mAttributes[IFD_INTEROPERABILITY_HINT].isEmpty()) {
1841            mAttributes[IFD_EXIF_HINT].put(IFD_POINTER_TAGS[2].name, "0");
1842        }
1843        if (!mAttributes[IFD_EXIF_HINT].isEmpty()) {
1844            mAttributes[IFD_TIFF_HINT].put(IFD_POINTER_TAGS[0].name, "0");
1845        }
1846        if (!mAttributes[IFD_GPS_HINT].isEmpty()) {
1847            mAttributes[IFD_TIFF_HINT].put(IFD_POINTER_TAGS[1].name, "0");
1848        }
1849        // Remove old thumbnail data
1850        setAttribute(JPEG_INTERCHANGE_FORMAT_TAG.name, null);
1851        setAttribute(JPEG_INTERCHANGE_FORMAT_LENGTH_TAG.name, null);
1852        if (mHasThumbnail) {
1853            mAttributes[IFD_TIFF_HINT].put(JPEG_INTERCHANGE_FORMAT_TAG.name, "0");
1854            mAttributes[IFD_TIFF_HINT].put(JPEG_INTERCHANGE_FORMAT_LENGTH_TAG.name,
1855                    String.valueOf(mThumbnailLength));
1856        }
1857
1858        // Remove null value tags.
1859        for (int hint = 0; hint < EXIF_TAGS.length; ++hint) {
1860            for (Object obj : mAttributes[hint].entrySet().toArray()) {
1861                Map.Entry entry = (Map.Entry) obj;
1862                if (entry.getValue() == null) {
1863                    mAttributes[hint].remove(entry.getKey());
1864                }
1865            }
1866        }
1867
1868        // Calculate IFD group data area sizes. IFD group data area is assigned to save the entry
1869        // value which has a bigger size than 4 bytes.
1870        for (int i = 0; i < 5; ++i) {
1871            int sum = 0;
1872            for (Map.Entry entry : (Set<Map.Entry>) mAttributes[i].entrySet()) {
1873                String entryValue = (String) ((Map.Entry) entry).getValue();
1874                int dataFormat = getDataFormatOfExifEntryValue(entryValue);
1875                int size = getSizeOfExifEntryValue(dataFormat, entryValue);
1876                if (size > 4) {
1877                    sum += size;
1878                }
1879            }
1880            ifdDataSizes[i] += sum;
1881        }
1882
1883        // Calculate IFD offsets.
1884        int position = 8;
1885        for (int hint = 0; hint < EXIF_TAGS.length; ++hint) {
1886            if (!mAttributes[hint].isEmpty()) {
1887                ifdOffsets[hint] = position;
1888                position += 2 + mAttributes[hint].size() * 12 + 4 + ifdDataSizes[hint];
1889            }
1890        }
1891        if (mHasThumbnail) {
1892            int thumbnailOffset = position;
1893            mAttributes[IFD_TIFF_HINT].put(JPEG_INTERCHANGE_FORMAT_TAG.name,
1894                    String.valueOf(thumbnailOffset));
1895            mAttributes[IFD_TIFF_HINT].put(JPEG_INTERCHANGE_FORMAT_LENGTH_TAG.name,
1896                    String.valueOf(mThumbnailLength));
1897            mThumbnailOffset = exifOffsetFromBeginning + thumbnailOffset;
1898            position += mThumbnailLength;
1899        }
1900
1901        // Calculate the total size
1902        int totalSize = position + 8;  // eight bytes is for header part.
1903        if (DEBUG) {
1904            Log.d(TAG, "totalSize length: " + totalSize);
1905            for (int i = 0; i < 5; ++i) {
1906                Log.d(TAG, String.format("index: %d, offsets: %d, tag count: %d, data sizes: %d",
1907                        i, ifdOffsets[i], mAttributes[i].size(), ifdDataSizes[i]));
1908            }
1909        }
1910
1911        // Update IFD pointer tags with the calculated offsets.
1912        if (!mAttributes[IFD_EXIF_HINT].isEmpty()) {
1913            mAttributes[IFD_TIFF_HINT].put(IFD_POINTER_TAGS[0].name,
1914                    String.valueOf(ifdOffsets[IFD_EXIF_HINT]));
1915        }
1916        if (!mAttributes[IFD_GPS_HINT].isEmpty()) {
1917            mAttributes[IFD_TIFF_HINT].put(IFD_POINTER_TAGS[1].name,
1918                    String.valueOf(ifdOffsets[IFD_GPS_HINT]));
1919        }
1920        if (!mAttributes[IFD_INTEROPERABILITY_HINT].isEmpty()) {
1921            mAttributes[IFD_EXIF_HINT].put(IFD_POINTER_TAGS[2].name,
1922                    String.valueOf(ifdOffsets[IFD_INTEROPERABILITY_HINT]));
1923        }
1924
1925        // Write TIFF Headers. See JEITA CP-3451C Table 1. page 10.
1926        dataOutputStream.writeUnsignedShort(totalSize);
1927        dataOutputStream.write(IDENTIFIER_APP1);
1928        dataOutputStream.writeShort(BYTE_ALIGN_MM);
1929        dataOutputStream.writeUnsignedShort(0x2a);
1930        dataOutputStream.writeUnsignedInt(8);
1931
1932        // Write IFD groups. See JEITA CP-3451C Figure 7. page 12.
1933        for (int hint = 0; hint < EXIF_TAGS.length; ++hint) {
1934            if (!mAttributes[hint].isEmpty()) {
1935                // See JEITA CP-3451C 4.6.2 IFD structure. page 13.
1936                // Write entry count
1937                dataOutputStream.writeUnsignedShort(mAttributes[hint].size());
1938
1939                // Write entry info
1940                int dataOffset = ifdOffsets[hint] + 2 + mAttributes[hint].size() * 12 + 4;
1941                for (Map.Entry entry : (Set<Map.Entry>) mAttributes[hint].entrySet()) {
1942                    // Convert tag name to tag number.
1943                    int tagNumber = (int) sExifTagMapsForWriting[hint].get(entry.getKey());
1944                    String entryValue = (String) entry.getValue();
1945
1946                    int dataFormat = getDataFormatOfExifEntryValue(entryValue);
1947                    int numberOfComponents = getNumberOfComponentsInExifEntryValue(dataFormat,
1948                            entryValue);
1949                    int byteCount = getSizeOfExifEntryValue(dataFormat, entryValue);
1950
1951                    dataOutputStream.writeUnsignedShort(tagNumber);
1952                    dataOutputStream.writeUnsignedShort(dataFormat);
1953                    dataOutputStream.writeInt(numberOfComponents);
1954                    if (byteCount > 4) {
1955                        dataOutputStream.writeUnsignedInt(dataOffset);
1956                        dataOffset += byteCount;
1957                    } else {
1958                        int bytesWritten = writeExifEntryValue(dataOutputStream, entryValue);
1959                        // Fill zero up to 4 bytes
1960                        if (bytesWritten < 4) {
1961                            for (int i = bytesWritten; i < 4; ++i) {
1962                                dataOutputStream.write(0);
1963                            }
1964                        }
1965                    }
1966                }
1967
1968                // Write the next offset. It writes the offset of thumbnail IFD if there is one or
1969                // more tags in the thumbnail IFD when the current IFD is the primary image TIFF
1970                // IFD; Otherwise 0.
1971                if (hint == 0 && !mAttributes[IFD_THUMBNAIL_HINT].isEmpty()) {
1972                    dataOutputStream.writeUnsignedInt(ifdOffsets[IFD_THUMBNAIL_HINT]);
1973                } else {
1974                    dataOutputStream.writeUnsignedInt(0);
1975                }
1976
1977                // Write values of data field exceeding 4 bytes after the next offset.
1978                for (Map.Entry entry : (Set<Map.Entry>) mAttributes[hint].entrySet()) {
1979                    String entryValue = (String) entry.getValue();
1980
1981                    int dataFormat = getDataFormatOfExifEntryValue(entryValue);
1982                    int byteCount = getSizeOfExifEntryValue(dataFormat, entryValue);
1983                    if (byteCount > 4) {
1984                        writeExifEntryValue(dataOutputStream, entryValue);
1985                    }
1986                }
1987            }
1988        }
1989
1990        // Write thumbnail
1991        if (mHasThumbnail) {
1992            dataOutputStream.write(getThumbnail());
1993        }
1994
1995        return totalSize;
1996    }
1997
1998    // Writes EXIF entry value and its entry value type will be automatically determined.
1999    private static int writeExifEntryValue(ExifDataOutputStream dataOutputStream, String entryValue)
2000            throws IOException {
2001        int bytesWritten = 0;
2002        int dataFormat = getDataFormatOfExifEntryValue(entryValue);
2003
2004        // Values can be composed of several components. Each component is separated by char ','.
2005        String[] components = entryValue.split(",");
2006        for (String component : components) {
2007            switch (dataFormat) {
2008                case IFD_FORMAT_SLONG:
2009                    dataOutputStream.writeInt(Integer.parseInt(component));
2010                    bytesWritten += 4;
2011                    break;
2012                case IFD_FORMAT_DOUBLE:
2013                    dataOutputStream.writeDouble(Double.parseDouble(component));
2014                    bytesWritten += 8;
2015                    break;
2016                case IFD_FORMAT_STRING:
2017                    byte[] asciiArray = (component + '\0').getBytes(Charset.forName("US-ASCII"));
2018                    dataOutputStream.write(asciiArray);
2019                    bytesWritten += asciiArray.length;
2020                    break;
2021                case IFD_FORMAT_SRATIONAL:
2022                    String[] rationalNumber = component.split("/");
2023                    dataOutputStream.writeInt(Integer.parseInt(rationalNumber[0]));
2024                    dataOutputStream.writeInt(Integer.parseInt(rationalNumber[1]));
2025                    bytesWritten += 8;
2026                    break;
2027                default:
2028                    throw new IllegalArgumentException();
2029            }
2030        }
2031        return bytesWritten;
2032    }
2033
2034    // Determines the data format of EXIF entry value.
2035    private static int getDataFormatOfExifEntryValue(String entryValue) {
2036        // See TIFF 6.0 spec Types. page 15.
2037        // Take the first component if there are more than one component.
2038        if (entryValue.contains(",")) {
2039            entryValue = entryValue.split(",")[0];
2040        }
2041
2042        if (entryValue.contains("/")) {
2043            return IFD_FORMAT_SRATIONAL;
2044        }
2045        try {
2046            Integer.parseInt(entryValue);
2047            return IFD_FORMAT_SLONG;
2048        } catch (NumberFormatException e) {
2049            // Ignored
2050        }
2051        try {
2052            Double.parseDouble(entryValue);
2053            return IFD_FORMAT_DOUBLE;
2054        } catch (NumberFormatException e) {
2055            // Ignored
2056        }
2057        return IFD_FORMAT_STRING;
2058    }
2059
2060    // Determines the size of EXIF entry value.
2061    private static int getSizeOfExifEntryValue(int dataFormat, String entryValue) {
2062        // See TIFF 6.0 spec Types page 15.
2063        int bytesEstimated = 0;
2064        String[] components = entryValue.split(",");
2065        for (String component : components) {
2066            switch (dataFormat) {
2067                case IFD_FORMAT_SLONG:
2068                    bytesEstimated += 4;
2069                    break;
2070                case IFD_FORMAT_DOUBLE:
2071                    bytesEstimated += 8;
2072                    break;
2073                case IFD_FORMAT_STRING:
2074                    bytesEstimated
2075                            += (component + '\0').getBytes(Charset.forName("US-ASCII")).length;
2076                    break;
2077                case IFD_FORMAT_SRATIONAL:
2078                    bytesEstimated += 8;
2079                    break;
2080                default:
2081                    throw new IllegalArgumentException();
2082            }
2083        }
2084        return bytesEstimated;
2085    }
2086
2087    // Determines the number of components of EXIF entry value.
2088    private static int getNumberOfComponentsInExifEntryValue(int dataFormat, String entryValue) {
2089        if (dataFormat == IFD_FORMAT_STRING) {
2090            return (entryValue + '\0').getBytes(Charset.forName("US-ASCII")).length;
2091        }
2092        int count = 1;
2093        for (int i = 0; i < entryValue.length(); ++i) {
2094            if (entryValue.charAt(i) == ',') {
2095                ++count;
2096            }
2097        }
2098        return count;
2099    }
2100
2101    // An input stream to parse EXIF data area, which can be written in either little or big endian
2102    // order.
2103    private static class ByteOrderAwarenessDataInputStream extends ByteArrayInputStream {
2104        private static final ByteOrder LITTLE_ENDIAN = ByteOrder.LITTLE_ENDIAN;
2105        private static final ByteOrder BIG_ENDIAN = ByteOrder.BIG_ENDIAN;
2106
2107        private ByteOrder mByteOrder = ByteOrder.BIG_ENDIAN;
2108        private final long mLength;
2109        private long mPosition;
2110
2111        public ByteOrderAwarenessDataInputStream(byte[] bytes) {
2112            super(bytes);
2113            mLength = bytes.length;
2114            mPosition = 0L;
2115        }
2116
2117        public void setByteOrder(ByteOrder byteOrder) {
2118            mByteOrder = byteOrder;
2119        }
2120
2121        public void seek(long byteCount) throws IOException {
2122            mPosition = 0L;
2123            reset();
2124            if (skip(byteCount) != byteCount) {
2125                throw new IOException("Couldn't seek up to the byteCount");
2126            }
2127        }
2128
2129        public long peek() {
2130            return mPosition;
2131        }
2132
2133        public void readFully(byte[] buffer) throws IOException {
2134            mPosition += buffer.length;
2135            if (mPosition > mLength) {
2136                throw new EOFException();
2137            }
2138            if (super.read(buffer, 0, buffer.length) != buffer.length) {
2139                throw new IOException("Couldn't read up to the length of buffer");
2140            }
2141        }
2142
2143        public byte readByte() throws IOException {
2144            ++mPosition;
2145            if (mPosition > mLength) {
2146                throw new EOFException();
2147            }
2148            int ch = super.read();
2149            if (ch < 0) {
2150                throw new EOFException();
2151            }
2152            return (byte) ch;
2153        }
2154
2155        public short readShort() throws IOException {
2156            mPosition += 2;
2157            if (mPosition > mLength) {
2158                throw new EOFException();
2159            }
2160            int ch1 = super.read();
2161            int ch2 = super.read();
2162            if ((ch1 | ch2) < 0) {
2163                throw new EOFException();
2164            }
2165            if (mByteOrder == LITTLE_ENDIAN) {
2166                return (short) ((ch2 << 8) + (ch1));
2167            } else if (mByteOrder == BIG_ENDIAN) {
2168                return (short) ((ch1 << 8) + (ch2));
2169            }
2170            throw new IOException("Invalid byte order: " + mByteOrder);
2171        }
2172
2173        public int readInt() throws IOException {
2174            mPosition += 4;
2175            if (mPosition > mLength) {
2176                throw new EOFException();
2177            }
2178            int ch1 = super.read();
2179            int ch2 = super.read();
2180            int ch3 = super.read();
2181            int ch4 = super.read();
2182            if ((ch1 | ch2 | ch3 | ch4) < 0) {
2183                throw new EOFException();
2184            }
2185            if (mByteOrder == LITTLE_ENDIAN) {
2186                return ((ch4 << 24) + (ch3 << 16) + (ch2 << 8) + ch1);
2187            } else if (mByteOrder == BIG_ENDIAN) {
2188                return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + ch4);
2189            }
2190            throw new IOException("Invalid byte order: " + mByteOrder);
2191        }
2192
2193        @Override
2194        public long skip(long byteCount) {
2195            long skipped = super.skip(Math.min(byteCount, mLength - mPosition));
2196            mPosition += skipped;
2197            return skipped;
2198        }
2199
2200        public int readUnsignedShort() throws IOException {
2201            mPosition += 2;
2202            if (mPosition > mLength) {
2203                throw new EOFException();
2204            }
2205            int ch1 = super.read();
2206            int ch2 = super.read();
2207            if ((ch1 | ch2) < 0) {
2208                throw new EOFException();
2209            }
2210            if (mByteOrder == LITTLE_ENDIAN) {
2211                return ((ch2 << 8) + (ch1));
2212            } else if (mByteOrder == BIG_ENDIAN) {
2213                return ((ch1 << 8) + (ch2));
2214            }
2215            throw new IOException("Invalid byte order: " + mByteOrder);
2216        }
2217
2218        public long readUnsignedInt() throws IOException {
2219            return readInt() & 0xffffffffL;
2220        }
2221
2222        public long readLong() throws IOException {
2223            mPosition += 8;
2224            if (mPosition > mLength) {
2225                throw new EOFException();
2226            }
2227            int ch1 = super.read();
2228            int ch2 = super.read();
2229            int ch3 = super.read();
2230            int ch4 = super.read();
2231            int ch5 = super.read();
2232            int ch6 = super.read();
2233            int ch7 = super.read();
2234            int ch8 = super.read();
2235            if ((ch1 | ch2 | ch3 | ch4 | ch5 | ch6 | ch7 | ch8) < 0) {
2236                throw new EOFException();
2237            }
2238            if (mByteOrder == LITTLE_ENDIAN) {
2239                return (((long) ch8 << 56) + ((long) ch7 << 48) + ((long) ch6 << 40)
2240                        + ((long) ch5 << 32) + ((long) ch4 << 24) + ((long) ch3 << 16)
2241                        + ((long) ch2 << 8) + (long) ch1);
2242            } else if (mByteOrder == BIG_ENDIAN) {
2243                return (((long) ch1 << 56) + ((long) ch2 << 48) + ((long) ch3 << 40)
2244                        + ((long) ch4 << 32) + ((long) ch5 << 24) + ((long) ch6 << 16)
2245                        + ((long) ch7 << 8) + (long) ch8);
2246            }
2247            throw new IOException("Invalid byte order: " + mByteOrder);
2248        }
2249
2250        public float readFloat() throws IOException {
2251            return Float.intBitsToFloat(readInt());
2252        }
2253
2254        public double readDouble() throws IOException {
2255            return Double.longBitsToDouble(readLong());
2256        }
2257    }
2258
2259    // An output stream to write EXIF data area, that will be written in big endian byte order.
2260    private static class ExifDataOutputStream extends DataOutputStream {
2261        public ExifDataOutputStream(OutputStream out) {
2262            super(out);
2263        }
2264
2265        public void writeUnsignedShort(int val) throws IOException {
2266            writeShort((short) val);
2267        }
2268
2269        public void writeUnsignedInt(long val) throws IOException {
2270            writeInt((int) val);
2271        }
2272    }
2273
2274    // JNI methods for RAW formats.
2275    private static native void nativeInitRaw();
2276    private static native byte[] nativeGetThumbnailFromAsset(
2277            long asset, int thumbnailOffset, int thumbnailLength);
2278    private static native HashMap nativeGetRawAttributesFromAsset(long asset);
2279    private static native HashMap nativeGetRawAttributesFromFileDescriptor(FileDescriptor fd);
2280    private static native HashMap nativeGetRawAttributesFromInputStream(InputStream in);
2281}
2282