• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* exif-tag.c
2  *
3  * Copyright (c) 2001 Lutz Mueller <lutz@users.sourceforge.net>
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this library; if not, write to the
17  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18  * Boston, MA  02110-1301  USA.
19  */
20 
21 #include <config.h>
22 
23 #include <libexif/exif-tag.h>
24 #include <libexif/i18n.h>
25 
26 #include <stdlib.h>
27 #include <string.h>
28 
29 #define ESL_NNNN { EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_NOT_RECORDED }
30 #define ESL_OOOO { EXIF_SUPPORT_LEVEL_OPTIONAL, EXIF_SUPPORT_LEVEL_OPTIONAL, EXIF_SUPPORT_LEVEL_OPTIONAL, EXIF_SUPPORT_LEVEL_OPTIONAL }
31 #define ESL_MMMN { EXIF_SUPPORT_LEVEL_MANDATORY, EXIF_SUPPORT_LEVEL_MANDATORY, EXIF_SUPPORT_LEVEL_MANDATORY, EXIF_SUPPORT_LEVEL_NOT_RECORDED }
32 #define ESL_MMMM { EXIF_SUPPORT_LEVEL_MANDATORY, EXIF_SUPPORT_LEVEL_MANDATORY, EXIF_SUPPORT_LEVEL_MANDATORY, EXIF_SUPPORT_LEVEL_MANDATORY }
33 #define ESL_OMON { EXIF_SUPPORT_LEVEL_OPTIONAL, EXIF_SUPPORT_LEVEL_MANDATORY, EXIF_SUPPORT_LEVEL_OPTIONAL, EXIF_SUPPORT_LEVEL_NOT_RECORDED }
34 #define ESL_NNOO { EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_OPTIONAL, EXIF_SUPPORT_LEVEL_OPTIONAL }
35 #define ESL_NNMN { EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_MANDATORY, EXIF_SUPPORT_LEVEL_NOT_RECORDED }
36 #define ESL_NNMM { EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_MANDATORY, EXIF_SUPPORT_LEVEL_MANDATORY }
37 #define ESL_NNNM { EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_MANDATORY }
38 #define ESL_NNNO { EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_NOT_RECORDED, EXIF_SUPPORT_LEVEL_OPTIONAL }
39 #define ESL_GPS { ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN }
40 
41 /*!
42  * Table giving information about each EXIF tag.
43  * There may be more than one entry with the same tag value because some tags
44  * have different meanings depending on the IFD in which they appear.
45  * When there are such duplicate entries, there must be no overlap in their
46  * support levels.
47  * The entries MUST be sorted in tag order.
48  * The name and title are mandatory, but the description may be an empty
49  * string. None of the entries may be NULL except the final array terminator.
50  */
51 static const struct TagEntry {
52 	/*! Tag ID. There may be duplicate tags when the same number is used for
53 	 * different meanings in different IFDs. */
54 	ExifTag tag;
55 	const char *name;
56 	const char *title;
57 	const char *description;
58 	/*! indexed by the types [ExifIfd][ExifDataType] */
59 	ExifSupportLevel esl[EXIF_IFD_COUNT][EXIF_DATA_TYPE_COUNT];
60 } ExifTagTable[] = {
61 #ifndef NO_VERBOSE_TAG_STRINGS
62 	{EXIF_TAG_GPS_VERSION_ID, "GPSVersionID", N_("GPS Tag Version"),
63 	 N_("Indicates the version of <GPSInfoIFD>. The version is given "
64 	    "as 2.0.0.0. This tag is mandatory when <GPSInfo> tag is "
65 	    "present. (Note: The <GPSVersionID> tag is given in bytes, "
66 	    "unlike the <ExifVersion> tag. When the version is "
67 	    "2.0.0.0, the tag value is 02000000.H)."), ESL_GPS},
68 	{EXIF_TAG_INTEROPERABILITY_INDEX, "InteroperabilityIndex",
69 	 N_("Interoperability Index"),
70 	 N_("Indicates the identification of the Interoperability rule. "
71 	    "Use \"R98\" for stating ExifR98 Rules. Four bytes used "
72 	    "including the termination code (NULL). see the separate "
73 	    "volume of Recommended Exif Interoperability Rules (ExifR98) "
74 	    "for other tags used for ExifR98."),
75 	 { ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_OOOO } },
76 	{EXIF_TAG_GPS_LATITUDE_REF, "GPSLatitudeRef", N_("North or South Latitude"),
77 	 N_("Indicates whether the latitude is north or south latitude. The "
78 	    "ASCII value 'N' indicates north latitude, and 'S' is south "
79 	    "latitude."), ESL_GPS},
80 	{EXIF_TAG_INTEROPERABILITY_VERSION, "InteroperabilityVersion",
81 	 N_("Interoperability Version"), "",
82 	 { ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_OOOO } },
83 	{EXIF_TAG_GPS_LATITUDE, "GPSLatitude", N_("Latitude"),
84 	 N_("Indicates the latitude. The latitude is expressed as three "
85 	    "RATIONAL values giving the degrees, minutes, and seconds, "
86 	    "respectively. When degrees, minutes and seconds are expressed, "
87 	    "the format is dd/1,mm/1,ss/1. When degrees and minutes are used "
88 	    "and, for example, fractions of minutes are given up to two "
89 	    "decimal places, the format is dd/1,mmmm/100,0/1."),
90 	 ESL_GPS},
91 	{EXIF_TAG_GPS_LONGITUDE_REF, "GPSLongitudeRef", N_("East or West Longitude"),
92 	 N_("Indicates whether the longitude is east or west longitude. "
93 	    "ASCII 'E' indicates east longitude, and 'W' is west "
94 	    "longitude."), ESL_GPS},
95 	{EXIF_TAG_GPS_LONGITUDE, "GPSLongitude", N_("Longitude"),
96 	 N_("Indicates the longitude. The longitude is expressed as three "
97 	    "RATIONAL values giving the degrees, minutes, and seconds, "
98 	    "respectively. When degrees, minutes and seconds are expressed, "
99 	    "the format is ddd/1,mm/1,ss/1. When degrees and minutes are "
100 	    "used and, for example, fractions of minutes are given up to "
101 	    "two decimal places, the format is ddd/1,mmmm/100,0/1."),
102 	 ESL_GPS},
103 	{EXIF_TAG_GPS_ALTITUDE_REF, "GPSAltitudeRef", N_("Altitude Reference"),
104 	 N_("Indicates the altitude used as the reference altitude. If the "
105 	    "reference is sea level and the altitude is above sea level, 0 "
106 	    "is given. If the altitude is below sea level, a value of 1 is given "
107 	    "and the altitude is indicated as an absolute value in the "
108 	    "GSPAltitude tag. The reference unit is meters. Note that this tag "
109 	    "is BYTE type, unlike other reference tags."), ESL_GPS},
110 	{EXIF_TAG_GPS_ALTITUDE, "GPSAltitude", N_("Altitude"),
111 	 N_("Indicates the altitude based on the reference in GPSAltitudeRef. "
112 	    "Altitude is expressed as one RATIONAL value. The reference unit "
113 	    "is meters."), ESL_GPS},
114 	{EXIF_TAG_GPS_TIME_STAMP, "GPSTimeStamp", N_("GPS Time (Atomic Clock)"),
115          N_("Indicates the time as UTC (Coordinated Universal Time). "
116 	    "TimeStamp is expressed as three RATIONAL values giving "
117             "the hour, minute, and second."), ESL_GPS},
118 	{EXIF_TAG_GPS_SATELLITES, "GPSSatellites", N_("GPS Satellites"),
119          N_("Indicates the GPS satellites used for measurements. This "
120             "tag can be used to describe the number of satellites, their ID "
121             "number, angle of elevation, azimuth, SNR and other information "
122             "in ASCII notation. The format is not specified. If the GPS "
123             "receiver is incapable of taking measurements, value of the tag "
124             "shall be set to NULL."), ESL_GPS},
125 	{EXIF_TAG_GPS_STATUS, "GPSStatus", N_("GPS Receiver Status"),
126          N_("Indicates the status of the GPS receiver when the image is "
127             "recorded. 'A' means measurement is in progress, and 'V' means "
128             "the measurement is Interoperability."), ESL_GPS},
129 	{EXIF_TAG_GPS_MEASURE_MODE, "GPSMeasureMode", N_("GPS Measurement Mode"),
130          N_("Indicates the GPS measurement mode. '2' means "
131             "two-dimensional measurement and '3' means three-dimensional "
132             "measurement is in progress."), ESL_GPS},
133 	{EXIF_TAG_GPS_DOP, "GPSDOP", N_("Measurement Precision"),
134          N_("Indicates the GPS DOP (data degree of precision). An HDOP "
135             "value is written during two-dimensional measurement, and PDOP "
136             "during three-dimensional measurement."), ESL_GPS},
137 	{EXIF_TAG_GPS_SPEED_REF, "GPSSpeedRef", N_("Speed Unit"),
138          N_("Indicates the unit used to express the GPS receiver speed "
139             "of movement. 'K', 'M' and 'N' represent kilometers per hour, "
140             "miles per hour, and knots."), ESL_GPS},
141 	{EXIF_TAG_GPS_SPEED, "GPSSpeed", N_("Speed of GPS Receiver"),
142 	 N_("Indicates the speed of GPS receiver movement."), ESL_GPS},
143 	{EXIF_TAG_GPS_TRACK_REF, "GPSTrackRef", N_("Reference for direction of movement"),
144          N_("Indicates the reference for giving the direction of GPS "
145             "receiver movement. 'T' denotes true direction and 'M' is "
146             "magnetic direction."), ESL_GPS},
147 	{EXIF_TAG_GPS_TRACK, "GPSTrack", N_("Direction of Movement"),
148          N_("Indicates the direction of GPS receiver movement. The range "
149             "of values is from 0.00 to 359.99."), ESL_GPS},
150 	{EXIF_TAG_GPS_IMG_DIRECTION_REF, "GPSImgDirectionRef", N_("GPS Image Direction Reference"),
151 	 N_("Indicates the reference for giving the direction of the image when it is captured. "
152 	    "'T' denotes true direction and 'M' is magnetic direction."), ESL_GPS},
153 	{EXIF_TAG_GPS_IMG_DIRECTION, "GPSImgDirection", N_("GPS Image Direction"),
154 	 N_("Indicates the direction of the image when it was captured. The range of values is "
155 	    "from 0.00 to 359.99."), ESL_GPS},
156 	{EXIF_TAG_GPS_MAP_DATUM, "GPSMapDatum", N_("Geodetic Survey Data Used"),
157          N_("Indicates the geodetic survey data used by the GPS "
158             "receiver. If the survey data is restricted to Japan, the value "
159             "of this tag is 'TOKYO' or 'WGS-84'. If a GPS Info tag is "
160             "recorded, it is strongly recommended that this tag be recorded."), ESL_GPS},
161 	{EXIF_TAG_GPS_DEST_LATITUDE_REF, "GPSDestLatitudeRef", N_("Reference For Latitude of Destination"),
162          N_("Indicates whether the latitude of the destination point is "
163             "north or south latitude. The ASCII value 'N' indicates north "
164             "latitude, and 'S' is south latitude."), ESL_GPS},
165 	{EXIF_TAG_GPS_DEST_LATITUDE, "GPSDestLatitude", N_("Latitude of Destination"),
166          N_("Indicates the latitude of the destination point. The "
167             "latitude is expressed as three RATIONAL values giving the "
168             "degrees, minutes, and seconds, respectively. If latitude is "
169             "expressed as degrees, minutes and seconds, a typical format "
170             "would be dd/1,mm/1,ss/1. When degrees and minutes are used and, "
171             "for example, fractions of minutes are given up to two decimal "
172             "places, the format would be dd/1,mmmm/100,0/1."), ESL_GPS},
173 	{EXIF_TAG_GPS_DEST_LONGITUDE_REF, "GPSDestLongitudeRef", N_("Reference for Longitude of Destination"),
174          N_("Indicates whether the longitude of the destination point is "
175             "east or west longitude. ASCII 'E' indicates east longitude, and "
176             "'W' is west longitude."), ESL_GPS},
177 	{EXIF_TAG_GPS_DEST_LONGITUDE, "GPSDestLongitude", N_("Longitude of Destination"),
178          N_("Indicates the longitude of the destination point. The "
179             "longitude is expressed as three RATIONAL values giving the "
180             "degrees, minutes, and seconds, respectively. If longitude is "
181             "expressed as degrees, minutes and seconds, a typical format "
182             "would be ddd/1,mm/1,ss/1. When degrees and minutes are used "
183             "and, for example, fractions of minutes are given up to two "
184             "decimal places, the format would be ddd/1,mmmm/100,0/1."),
185          ESL_GPS},
186 	{EXIF_TAG_GPS_DEST_BEARING_REF, "GPSDestBearingRef", N_("Reference for Bearing of Destination"),
187          N_("Indicates the reference used for giving the bearing to "
188             "the destination point. 'T' denotes true direction and 'M' is "
189             "magnetic direction."), ESL_GPS},
190 	{EXIF_TAG_GPS_DEST_BEARING, "GPSDestBearing", N_("Bearing of Destination"),
191          N_("Indicates the bearing to the destination point. The range "
192             "of values is from 0.00 to 359.99."), ESL_GPS},
193 	{EXIF_TAG_GPS_DEST_DISTANCE_REF, "GPSDestDistanceRef", N_("Reference for Distance to Destination"),
194          N_("Indicates the unit used to express the distance to the "
195             "destination point. 'K', 'M' and 'N' represent kilometers, miles "
196             "and nautical miles."), ESL_GPS},
197 	{EXIF_TAG_GPS_DEST_DISTANCE, "GPSDestDistance", N_("Distance to Destination"),
198 	 N_("Indicates the distance to the destination point."), ESL_GPS},
199 	{EXIF_TAG_GPS_PROCESSING_METHOD, "GPSProcessingMethod", N_("Name of GPS Processing Method"),
200          N_("A character string recording the name of the method used "
201             "for location finding. The first byte indicates the character "
202             "code used, and this is followed by the name "
203             "of the method. Since the Type is not ASCII, NULL termination is "
204             "not necessary."), ESL_GPS},
205 	{EXIF_TAG_GPS_AREA_INFORMATION, "GPSAreaInformation", N_("Name of GPS Area"),
206          N_("A character string recording the name of the GPS area. The "
207             "first byte indicates the character code used, "
208             "and this is followed by the name of the GPS area. Since "
209             "the Type is not ASCII, NULL termination is not necessary."), ESL_GPS},
210 	{EXIF_TAG_GPS_DATE_STAMP, "GPSDateStamp", N_("GPS Date"),
211          N_("A character string recording date and time information "
212             "relative to UTC (Coordinated Universal Time). The format is "
213             "\"YYYY:MM:DD\". The length of the string is 11 bytes including "
214             "NULL."), ESL_GPS},
215 	{EXIF_TAG_GPS_DIFFERENTIAL, "GPSDifferential", N_("GPS Differential Correction"),
216          N_("Indicates whether differential correction is applied to the "
217             "GPS receiver."), ESL_GPS},
218 	/* Not in EXIF 2.2 */
219 	{EXIF_TAG_NEW_SUBFILE_TYPE, "NewSubfileType",
220 	 N_("New Subfile Type"), N_("A general indication of the kind of data "
221 	    "contained in this subfile.")},
222 	{EXIF_TAG_IMAGE_WIDTH, "ImageWidth", N_("Image Width"),
223 	 N_("The number of columns of image data, equal to the number of "
224 	    "pixels per row. In JPEG compressed data a JPEG marker is "
225 	    "used instead of this tag."),
226 	 { ESL_MMMN, ESL_MMMN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
227 	{EXIF_TAG_IMAGE_LENGTH, "ImageLength", N_("Image Length"),
228 	 N_("The number of rows of image data. In JPEG compressed data a "
229 	    "JPEG marker is used instead of this tag."),
230 	 { ESL_MMMN, ESL_MMMN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
231 	{EXIF_TAG_BITS_PER_SAMPLE, "BitsPerSample", N_("Bits per Sample"),
232 	 N_("The number of bits per image component. In this standard each "
233 	    "component of the image is 8 bits, so the value for this "
234 	    "tag is 8. See also <SamplesPerPixel>. In JPEG compressed data "
235 	    "a JPEG marker is used instead of this tag."),
236 	 { ESL_MMMN, ESL_MMMN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
237 	{EXIF_TAG_COMPRESSION, "Compression", N_("Compression"),
238 	 N_("The compression scheme used for the image data. When a "
239 	    "primary image is JPEG compressed, this designation is "
240 	    "not necessary and is omitted. When thumbnails use JPEG "
241 	    "compression, this tag value is set to 6."),
242 	 { ESL_MMMN, ESL_MMMM, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
243 	{EXIF_TAG_PHOTOMETRIC_INTERPRETATION, "PhotometricInterpretation",
244 	 N_("Photometric Interpretation"),
245 	 N_("The pixel composition. In JPEG compressed data a JPEG "
246 	    "marker is used instead of this tag."),
247 	 { ESL_MMMN, ESL_MMMN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
248 	/* Not in EXIF 2.2 */
249 	{EXIF_TAG_FILL_ORDER, "FillOrder", N_("Fill Order"), ""},
250 	/* Not in EXIF 2.2 */
251 	{EXIF_TAG_DOCUMENT_NAME, "DocumentName", N_("Document Name"), ""},
252 	{EXIF_TAG_IMAGE_DESCRIPTION, "ImageDescription",
253 	 N_("Image Description"),
254 	 N_("A character string giving the title of the image. It may be "
255 	    "a comment such as \"1988 company picnic\" or "
256 	    "the like. Two-bytes character codes cannot be used. "
257 	    "When a 2-bytes code is necessary, the Exif Private tag "
258 	    "<UserComment> is to be used."),
259 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
260 	{EXIF_TAG_MAKE, "Make", N_("Manufacturer"),
261 	 N_("The manufacturer of the recording "
262 	    "equipment. This is the manufacturer of the DSC, scanner, "
263 	    "video digitizer or other equipment that generated the "
264 	    "image. When the field is left blank, it is treated as "
265 	    "unknown."),
266 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
267 	{EXIF_TAG_MODEL, "Model", N_("Model"),
268 	 N_("The model name or model number of the equipment. This is the "
269 	    "model name or number of the DSC, scanner, video digitizer "
270 	    "or other equipment that generated the image. When the field "
271 	    "is left blank, it is treated as unknown."),
272 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
273 	{EXIF_TAG_STRIP_OFFSETS, "StripOffsets", N_("Strip Offsets"),
274 	 N_("For each strip, the byte offset of that strip. It is "
275 	    "recommended that this be selected so the number of strip "
276 	    "bytes does not exceed 64 Kbytes. With JPEG compressed "
277 	    "data this designation is not needed and is omitted. See also "
278 	    "<RowsPerStrip> and <StripByteCounts>."),
279 	 { ESL_MMMN, ESL_MMMN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
280 	{EXIF_TAG_ORIENTATION, "Orientation", N_("Orientation"),
281 	 N_("The image orientation viewed in terms of rows and columns."),
282 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
283 	{EXIF_TAG_SAMPLES_PER_PIXEL, "SamplesPerPixel",
284 	 N_("Samples per Pixel"),
285 	 N_("The number of components per pixel. Since this standard applies "
286 	    "to RGB and YCbCr images, the value set for this tag is 3. "
287 	    "In JPEG compressed data a JPEG marker is used instead of this "
288 	    "tag."),
289 	 { ESL_MMMN, ESL_MMMN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
290 	{EXIF_TAG_ROWS_PER_STRIP, "RowsPerStrip", N_("Rows per Strip"),
291 	 N_("The number of rows per strip. This is the number of rows "
292 	    "in the image of one strip when an image is divided into "
293 	    "strips. With JPEG compressed data this designation is not "
294 	    "needed and is omitted. See also <StripOffsets> and "
295 	    "<StripByteCounts>."),
296 	 { ESL_MMMN, ESL_MMMN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
297 	{EXIF_TAG_STRIP_BYTE_COUNTS, "StripByteCounts", N_("Strip Byte Count"),
298 	 N_("The total number of bytes in each strip. With JPEG compressed "
299 	    "data this designation is not needed and is omitted."),
300 	 { ESL_MMMN, ESL_MMMN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
301 	{EXIF_TAG_X_RESOLUTION, "XResolution", N_("X-Resolution"),
302 	 N_("The number of pixels per <ResolutionUnit> in the <ImageWidth> "
303 	    "direction. When the image resolution is unknown, 72 [dpi] "
304 	    "is designated."),
305 	 { ESL_MMMM, ESL_MMMM, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
306 	{EXIF_TAG_Y_RESOLUTION, "YResolution", N_("Y-Resolution"),
307 	 N_("The number of pixels per <ResolutionUnit> in the <ImageLength> "
308 	    "direction. The same value as <XResolution> is designated."),
309 	 { ESL_MMMM, ESL_MMMM, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
310 	{EXIF_TAG_PLANAR_CONFIGURATION, "PlanarConfiguration",
311 	 N_("Planar Configuration"),
312 	 N_("Indicates whether pixel components are recorded in a chunky "
313 	    "or planar format. In JPEG compressed files a JPEG marker "
314 	    "is used instead of this tag. If this field does not exist, "
315 	    "the TIFF default of 1 (chunky) is assumed."),
316 	 { ESL_OMON, ESL_OMON, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
317 	{EXIF_TAG_RESOLUTION_UNIT, "ResolutionUnit", N_("Resolution Unit"),
318 	 N_("The unit for measuring <XResolution> and <YResolution>. The same "
319 	    "unit is used for both <XResolution> and <YResolution>. If "
320 	    "the image resolution is unknown, 2 (inches) is designated."),
321 	 { ESL_MMMM, ESL_MMMM, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
322 	{EXIF_TAG_TRANSFER_FUNCTION, "TransferFunction",
323 	 N_("Transfer Function"),
324 	 N_("A transfer function for the image, described in tabular style. "
325 	    "Normally this tag is not necessary, since color space is "
326 	    "specified in the color space information tag (<ColorSpace>)."),
327 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
328 	{EXIF_TAG_SOFTWARE, "Software", N_("Software"),
329 	 N_("This tag records the name and version of the software or "
330 	    "firmware of the camera or image input device used to "
331 	    "generate the image. The detailed format is not specified, but "
332 	    "it is recommended that the example shown below be "
333 	    "followed. When the field is left blank, it is treated as "
334 	    "unknown."),
335 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
336 	{EXIF_TAG_DATE_TIME, "DateTime", N_("Date and Time"),
337 	 N_("The date and time of image creation. In this standard "
338 	    "(EXIF-2.1) it is the date and time the file was changed."),
339 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
340 	{EXIF_TAG_ARTIST, "Artist", N_("Artist"),
341 	 N_("This tag records the name of the camera owner, photographer or "
342 	    "image creator. The detailed format is not specified, but it is "
343 	    "recommended that the information be written as in the example "
344 	    "below for ease of Interoperability. When the field is "
345 	    "left blank, it is treated as unknown."),
346 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
347 	{EXIF_TAG_WHITE_POINT, "WhitePoint", N_("White Point"),
348 	 N_("The chromaticity of the white point of the image. Normally "
349 	    "this tag is not necessary, since color space is specified "
350 	    "in the color space information tag (<ColorSpace>)."),
351 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
352 	{EXIF_TAG_PRIMARY_CHROMATICITIES, "PrimaryChromaticities",
353 	 N_("Primary Chromaticities"),
354 	 N_("The chromaticity of the three primary colors of the image. "
355 	    "Normally this tag is not necessary, since color space is "
356 	    "specified in the color space information tag (<ColorSpace>)."),
357 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
358 	/* Not in EXIF 2.2 */
359 	{EXIF_TAG_SUB_IFDS, "SubIFDs", "SubIFD Offsets", N_("Defined by Adobe Corporation "
360 	    "to enable TIFF Trees within a TIFF file.")},
361 	/* Not in EXIF 2.2 */
362 	{EXIF_TAG_TRANSFER_RANGE, "TransferRange", N_("Transfer Range"), ""},
363 	/* Not in EXIF 2.2 */
364 	{EXIF_TAG_JPEG_PROC, "JPEGProc", "JPEGProc", ""},
365 	{EXIF_TAG_JPEG_INTERCHANGE_FORMAT, "JPEGInterchangeFormat",
366 	 N_("JPEG Interchange Format"),
367 	 N_("The offset to the start byte (SOI) of JPEG compressed "
368 	    "thumbnail data. This is not used for primary image "
369 	    "JPEG data."),
370 	 { ESL_NNNN, ESL_NNNM, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
371 	{EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH,
372 	 "JPEGInterchangeFormatLength", N_("JPEG Interchange Format Length"),
373 	 N_("The number of bytes of JPEG compressed thumbnail data. This "
374 	    "is not used for primary image JPEG data. JPEG thumbnails "
375 	    "are not divided but are recorded as a continuous JPEG "
376 	    "bitstream from SOI to EOI. Appn and COM markers should "
377 	    "not be recorded. Compressed thumbnails must be recorded in no "
378 	    "more than 64 Kbytes, including all other data to be "
379 	    "recorded in APP1."),
380 	 { ESL_NNNN, ESL_NNNM, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
381 	{EXIF_TAG_YCBCR_COEFFICIENTS, "YCbCrCoefficients",
382 	 N_("YCbCr Coefficients"),
383 	 N_("The matrix coefficients for transformation from RGB to YCbCr "
384 	    "image data. No default is given in TIFF; but here the "
385 	    "value given in \"Color Space Guidelines\", is used "
386 	    "as the default. The color space is declared in a "
387 	    "color space information tag, with the default being the value "
388 	    "that gives the optimal image characteristics "
389 	    "Interoperability this condition."),
390 	 { ESL_NNOO, ESL_NNOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
391 	{EXIF_TAG_YCBCR_SUB_SAMPLING, "YCbCrSubSampling",
392 	 N_("YCbCr Sub-Sampling"),
393 	 N_("The sampling ratio of chrominance components in relation to the "
394 	    "luminance component. In JPEG compressed data a JPEG marker "
395 	    "is used instead of this tag."),
396 	 { ESL_NNMN, ESL_NNMN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
397 	{EXIF_TAG_YCBCR_POSITIONING, "YCbCrPositioning",
398 	 N_("YCbCr Positioning"),
399 	 N_("The position of chrominance components in relation to the "
400 	    "luminance component. This field is designated only for "
401 	    "JPEG compressed data or uncompressed YCbCr data. The TIFF "
402 	    "default is 1 (centered); but when Y:Cb:Cr = 4:2:2 it is "
403 	    "recommended in this standard that 2 (co-sited) be used to "
404 	    "record data, in order to improve the image quality when viewed "
405 	    "on TV systems. When this field does not exist, the reader shall "
406 	    "assume the TIFF default. In the case of Y:Cb:Cr = 4:2:0, the "
407 	    "TIFF default (centered) is recommended. If the reader "
408 	    "does not have the capability of supporting both kinds of "
409 	    "<YCbCrPositioning>, it shall follow the TIFF default regardless "
410 	    "of the value in this field. It is preferable that readers "
411 	    "be able to support both centered and co-sited positioning."),
412 	 { ESL_NNMM, ESL_NNOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
413 	{EXIF_TAG_REFERENCE_BLACK_WHITE, "ReferenceBlackWhite",
414 	 N_("Reference Black/White"),
415 	 N_("The reference black point value and reference white point "
416 	    "value. No defaults are given in TIFF, but the values "
417 	    "below are given as defaults here. The color space is declared "
418 	    "in a color space information tag, with the default "
419 	    "being the value that gives the optimal image characteristics "
420 	    "Interoperability these conditions."),
421 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
422 	/* Not in EXIF 2.2 */
423 	{EXIF_TAG_XML_PACKET, "XMLPacket", N_("XML Packet"), N_("XMP Metadata")},
424 	/* Not in EXIF 2.2 */
425 	{EXIF_TAG_RELATED_IMAGE_FILE_FORMAT, "RelatedImageFileFormat",
426 	 "RelatedImageFileFormat", ""},
427 	/* Not in EXIF 2.2 */
428 	{EXIF_TAG_RELATED_IMAGE_WIDTH, "RelatedImageWidth",
429 	 "RelatedImageWidth", ""},
430 	/* Not in EXIF 2.2 */
431 	{EXIF_TAG_RELATED_IMAGE_LENGTH, "RelatedImageLength",
432 	 "RelatedImageLength", ""},
433 	/* Not in EXIF 2.2 */
434 	{EXIF_TAG_CFA_REPEAT_PATTERN_DIM, "CFARepeatPatternDim",
435 	 "CFARepeatPatternDim", ""},
436 	/* Not in EXIF 2.2 */
437 	{EXIF_TAG_CFA_PATTERN, "CFAPattern",
438 	 N_("CFA Pattern"),
439 	 N_("Indicates the color filter array (CFA) geometric pattern of the "
440 	    "image sensor when a one-chip color area sensor is used. "
441 	    "It does not apply to all sensing methods.")},
442 	/* Not in EXIF 2.2 */
443 	{EXIF_TAG_BATTERY_LEVEL, "BatteryLevel", N_("Battery Level"), ""},
444 	{EXIF_TAG_COPYRIGHT, "Copyright", N_("Copyright"),
445 	 N_("Copyright information. In this standard the tag is used to "
446 	    "indicate both the photographer and editor copyrights. It is "
447 	    "the copyright notice of the person or organization claiming "
448 	    "rights to the image. The Interoperability copyright "
449 	    "statement including date and rights should be written in this "
450 	    "field; e.g., \"Copyright, John Smith, 19xx. All rights "
451 	    "reserved.\". In this standard the field records both the "
452 	    "photographer and editor copyrights, with each recorded in a "
453 	    "separate part of the statement. When there is a clear "
454 	    "distinction between the photographer and editor copyrights, "
455 	    "these are to be written in the order of photographer followed "
456 	    "by editor copyright, separated by NULL (in this case, "
457 	    "since the statement also ends with a NULL, there are two NULL "
458 	    "codes) (see example 1). When only the photographer is given, "
459 	    "it is terminated by one NULL code (see example 2). When only "
460 	    "the editor copyright is given, "
461 	    "the photographer copyright part consists of one space followed "
462 	    "by a terminating NULL code, then the editor copyright is given "
463 	    "(see example 3). When the field is left blank, it is treated "
464 	    "as unknown."),
465 	 { ESL_OOOO, ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
466 	{EXIF_TAG_EXPOSURE_TIME, "ExposureTime", N_("Exposure Time"),
467 	 N_("Exposure time, given in seconds (sec)."),
468 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
469 	{EXIF_TAG_FNUMBER, "FNumber", N_("F-Number"),
470 	 N_("The F number."),
471 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
472 	/* Not in EXIF 2.2 */
473 	{EXIF_TAG_IPTC_NAA, "IPTC/NAA", "IPTC/NAA", ""},
474 	/* Not in EXIF 2.2 */
475 	{EXIF_TAG_IMAGE_RESOURCES, "ImageResources", N_("Image Resources Block"), ""},
476 	{EXIF_TAG_EXIF_IFD_POINTER, "ExifIfdPointer", "ExifIFDPointer",
477 	 N_("A pointer to the Exif IFD. Interoperability, Exif IFD has the "
478 	    "same structure as that of the IFD specified in TIFF. "
479 	    "ordinarily, however, it does not contain image data as in "
480 	    "the case of TIFF."),
481 	 { ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
482 	/* Not in EXIF 2.2 */
483 	{EXIF_TAG_INTER_COLOR_PROFILE, "InterColorProfile",
484 	 "InterColorProfile", ""},
485 	{EXIF_TAG_EXPOSURE_PROGRAM, "ExposureProgram", N_("Exposure Program"),
486 	 N_("The class of the program used by the camera to set exposure "
487 	    "when the picture is taken."),
488 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
489 	{EXIF_TAG_SPECTRAL_SENSITIVITY, "SpectralSensitivity",
490 	 N_("Spectral Sensitivity"),
491 	 N_("Indicates the spectral sensitivity of each channel of the "
492 	    "camera used. The tag value is an ASCII string compatible "
493 	    "with the standard developed by the ASTM Technical Committee."),
494 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
495 	{EXIF_TAG_GPS_INFO_IFD_POINTER, "GPSInfoIFDPointer",
496 	 N_("GPS Info IFD Pointer"),
497 	 N_("A pointer to the GPS Info IFD. The "
498 	    "Interoperability structure of the GPS Info IFD, like that of "
499 	    "Exif IFD, has no image data."),
500 	 { ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
501 
502 	{EXIF_TAG_ISO_SPEED_RATINGS, "ISOSpeedRatings",
503 	 N_("ISO Speed Ratings"),
504 	 N_("Indicates the ISO Speed and ISO Latitude of the camera or "
505 	    "input device as specified in ISO 12232."),
506 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
507 	{EXIF_TAG_OECF, "OECF", N_("Opto-Electronic Conversion Function"),
508 	 N_("Indicates the Opto-Electronic Conversion Function (OECF) "
509 	    "specified in ISO 14524. <OECF> is the relationship between "
510 	    "the camera optical input and the image values."),
511 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
512 	/* Not in EXIF 2.2 */
513 	{EXIF_TAG_TIME_ZONE_OFFSET, "TimeZoneOffset", N_("Time Zone Offset"),
514 	 N_("Encodes time zone of camera clock relative to GMT.")},
515 	{EXIF_TAG_EXIF_VERSION, "ExifVersion", N_("Exif Version"),
516 	 N_("The version of this standard supported. Nonexistence of this "
517 	    "field is taken to mean nonconformance to the standard."),
518 	 { ESL_NNNN, ESL_NNNN, ESL_MMMM, ESL_NNNN, ESL_NNNN } },
519 	{EXIF_TAG_DATE_TIME_ORIGINAL, "DateTimeOriginal",
520 	 N_("Date and Time (Original)"),
521 	 N_("The date and time when the original image data was generated. "
522 	    "For a digital still camera "
523 	    "the date and time the picture was taken are recorded."),
524 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
525 	{EXIF_TAG_DATE_TIME_DIGITIZED, "DateTimeDigitized",
526 	 N_("Date and Time (Digitized)"),
527 	 N_("The date and time when the image was stored as digital data."),
528 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
529 	{EXIF_TAG_COMPONENTS_CONFIGURATION, "ComponentsConfiguration",
530 	 N_("Components Configuration"),
531 	 N_("Information specific to compressed data. The channels of "
532 	    "each component are arranged in order from the 1st "
533 	    "component to the 4th. For uncompressed data the data "
534 	    "arrangement is given in the <PhotometricInterpretation> tag. "
535 	    "However, since <PhotometricInterpretation> can only "
536 	    "express the order of Y, Cb and Cr, this tag is provided "
537 	    "for cases when compressed data uses components other than "
538 	    "Y, Cb, and Cr and to enable support of other sequences."),
539 	 { ESL_NNNN, ESL_NNNN, ESL_NNNM, ESL_NNNN, ESL_NNNN } },
540 	{EXIF_TAG_COMPRESSED_BITS_PER_PIXEL, "CompressedBitsPerPixel",
541 	 N_("Compressed Bits per Pixel"),
542 	 N_("Information specific to compressed data. The compression mode "
543 	    "used for a compressed image is indicated in unit bits "
544 	    "per pixel."),
545 	 { ESL_NNNN, ESL_NNNN, ESL_NNNO, ESL_NNNN, ESL_NNNN } },
546 	{EXIF_TAG_SHUTTER_SPEED_VALUE, "ShutterSpeedValue", N_("Shutter Speed"),
547 	 N_("Shutter speed. The unit is the APEX (Additive System of "
548 	    "Photographic Exposure) setting."),
549 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
550 	{EXIF_TAG_APERTURE_VALUE, "ApertureValue", N_("Aperture"),
551 	 N_("The lens aperture. The unit is the APEX value."),
552 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
553 	{EXIF_TAG_BRIGHTNESS_VALUE, "BrightnessValue", N_("Brightness"),
554 	 N_("The value of brightness. The unit is the APEX value. "
555 	    "Ordinarily it is given in the range of -99.99 to 99.99."),
556 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
557 	{EXIF_TAG_EXPOSURE_BIAS_VALUE, "ExposureBiasValue",
558 	 N_("Exposure Bias"),
559 	 N_("The exposure bias. The units is the APEX value. Ordinarily "
560 	    "it is given in the range of -99.99 to 99.99."),
561 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
562 	{EXIF_TAG_MAX_APERTURE_VALUE, "MaxApertureValue", N_("Maximum Aperture Value"),
563 	 N_("The smallest F number of the lens. The unit is the APEX value. "
564 	    "Ordinarily it is given in the range of 00.00 to 99.99, "
565 	    "but it is not limited to this range."),
566 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
567 	{EXIF_TAG_SUBJECT_DISTANCE, "SubjectDistance",
568 	 N_("Subject Distance"),
569 	 N_("The distance to the subject, given in meters."),
570 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
571 	{EXIF_TAG_METERING_MODE, "MeteringMode", N_("Metering Mode"),
572 	 N_("The metering mode."),
573 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
574 	{EXIF_TAG_LIGHT_SOURCE, "LightSource", N_("Light Source"),
575 	 N_("The kind of light source."),
576 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
577 	{EXIF_TAG_FLASH, "Flash", N_("Flash"),
578 	 N_("This tag is recorded when an image is taken using a strobe "
579 	    "light (flash)."),
580 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
581 	{EXIF_TAG_FOCAL_LENGTH, "FocalLength", N_("Focal Length"),
582 	 N_("The actual focal length of the lens, in mm. Conversion is not "
583 	    "made to the focal length of a 35 mm film camera."),
584 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
585 	{EXIF_TAG_SUBJECT_AREA, "SubjectArea", N_("Subject Area"),
586 	 N_("This tag indicates the location and area of the main subject "
587 	    "in the overall scene."),
588 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
589 	/* Not in EXIF 2.2 */
590 	{EXIF_TAG_TIFF_EP_STANDARD_ID, "TIFF/EPStandardID", N_("TIFF/EP Standard ID"), ""},
591 	{EXIF_TAG_MAKER_NOTE, "MakerNote", N_("Maker Note"),
592 	 N_("A tag for manufacturers of Exif writers to record any desired "
593 	    "information. The contents are up to the manufacturer."),
594 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
595 	{EXIF_TAG_USER_COMMENT, "UserComment", N_("User Comment"),
596 	 N_("A tag for Exif users to write keywords or comments on the image "
597 	    "besides those in <ImageDescription>, and without the "
598 	    "character code limitations of the <ImageDescription> tag. The "
599 	    "character code used in the <UserComment> tag is identified "
600 	    "based on an ID code in a fixed 8-byte area at the start of "
601 	    "the tag data area. The unused portion of the area is padded "
602 	    "with NULL (\"00.h\"). ID codes are assigned by means of "
603 	    "registration. The designation method and references for each "
604 	    "character code are defined in the specification. The value of "
605 	    "CountN is determined based on the 8 bytes in the character code "
606 	    "area and the number of bytes in the user comment part. Since "
607 	    "the TYPE is not ASCII, NULL termination is not necessary. "
608 	    "The ID code for the <UserComment> area may be a Defined code "
609 	    "such as JIS or ASCII, or may be Undefined. The Undefined name "
610 	    "is UndefinedText, and the ID code is filled with 8 bytes of all "
611 	    "\"NULL\" (\"00.H\"). An Exif reader that reads the "
612 	    "<UserComment> tag must have a function for determining the "
613 	    "ID code. This function is not required in Exif readers that "
614 	    "do not use the <UserComment> tag. "
615 	    "When a <UserComment> area is set aside, it is recommended that "
616 	    "the ID code be ASCII and that the following user comment "
617 	    "part be filled with blank characters [20.H]."),
618 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
619 	{EXIF_TAG_SUB_SEC_TIME, "SubsecTime", N_("Sub-second Time"),
620 	 N_("A tag used to record fractions of seconds for the "
621 	    "<DateTime> tag."),
622 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
623 	{EXIF_TAG_SUB_SEC_TIME_ORIGINAL, "SubSecTimeOriginal",
624 	 N_("Sub-second Time (Original)"),
625 	 N_("A tag used to record fractions of seconds for the "
626 	    "<DateTimeOriginal> tag."),
627 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
628 	{EXIF_TAG_SUB_SEC_TIME_DIGITIZED, "SubSecTimeDigitized",
629 	 N_("Sub-second Time (Digitized)"),
630 	 N_("A tag used to record fractions of seconds for the "
631 	    "<DateTimeDigitized> tag."),
632 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
633 	/* Not in EXIF 2.2 (Microsoft extension) */
634 	{EXIF_TAG_XP_TITLE, "XPTitle", N_("XP Title"),
635 	 N_("A character string giving the title of the image, encoded in "
636 	    "UTF-16LE."),
637 	 { ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
638 	/* Not in EXIF 2.2 (Microsoft extension) */
639 	{EXIF_TAG_XP_COMMENT, "XPComment", N_("XP Comment"),
640 	 N_("A character string containing a comment about the image, encoded "
641 	    "in UTF-16LE."),
642 	 { ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
643 	/* Not in EXIF 2.2 (Microsoft extension) */
644 	{EXIF_TAG_XP_AUTHOR, "XPAuthor", N_("XP Author"),
645 	 N_("A character string containing the name of the image creator, "
646 	    "encoded in UTF-16LE."),
647 	 { ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
648 	/* Not in EXIF 2.2 (Microsoft extension) */
649 	{EXIF_TAG_XP_KEYWORDS, "XPKeywords", N_("XP Keywords"),
650 	 N_("A character string containing key words describing the image, "
651 	    "encoded in UTF-16LE."),
652 	 { ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
653 	/* Not in EXIF 2.2 (Microsoft extension) */
654 	{EXIF_TAG_XP_SUBJECT, "XPSubject", N_("XP Subject"),
655 	 N_("A character string giving the image subject, encoded in "
656 	    "UTF-16LE."),
657 	 { ESL_OOOO, ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
658 	{EXIF_TAG_FLASH_PIX_VERSION, "FlashPixVersion", "FlashPixVersion",
659 	 N_("The FlashPix format version supported by a FPXR file."),
660 	 { ESL_NNNN, ESL_NNNN, ESL_MMMM, ESL_NNNN, ESL_NNNN } },
661 	{EXIF_TAG_COLOR_SPACE, "ColorSpace", N_("Color Space"),
662 	 N_("The color space information tag is always "
663 	    "recorded as the color space specifier. Normally sRGB (=1) "
664 	    "is used to define the color space based on the PC monitor "
665 	    "conditions and environment. If a color space other than "
666 	    "sRGB is used, Uncalibrated (=FFFF.H) is set. Image data "
667 	    "recorded as Uncalibrated can be treated as sRGB when it is "
668 	    "converted to FlashPix."),
669 	 { ESL_NNNN, ESL_NNNN, ESL_MMMM, ESL_NNNN, ESL_NNNN } },
670 	{EXIF_TAG_PIXEL_X_DIMENSION, "PixelXDimension", N_("Pixel X Dimension"),
671 	 N_("Information specific to compressed data. When a "
672 	    "compressed file is recorded, the valid width of the "
673 	    "meaningful image must be recorded in this tag, whether or "
674 	    "not there is padding data or a restart marker. This tag "
675 	    "should not exist in an uncompressed file."),
676 	 { ESL_NNNN, ESL_NNNN, ESL_NNNM, ESL_NNNN, ESL_NNNN } },
677 	{EXIF_TAG_PIXEL_Y_DIMENSION, "PixelYDimension", N_("Pixel Y Dimension"),
678 	 N_("Information specific to compressed data. When a compressed "
679 	    "file is recorded, the valid height of the meaningful image "
680 	    "must be recorded in this tag, whether or not there is padding "
681 	    "data or a restart marker. This tag should not exist in an "
682 	    "uncompressed file. "
683 	    "Since data padding is unnecessary in the vertical direction, "
684 	    "the number of lines recorded in this valid image height tag "
685 	    "will in fact be the same as that recorded in the SOF."),
686 	 { ESL_NNNN, ESL_NNNN, ESL_NNNM, ESL_NNNN, ESL_NNNN } },
687 	{EXIF_TAG_RELATED_SOUND_FILE, "RelatedSoundFile",
688 	 N_("Related Sound File"),
689 	 N_("This tag is used to record the name of an audio file related "
690 	    "to the image data. The only relational information "
691 	    "recorded here is the Exif audio file name and extension (an "
692 	    "ASCII string consisting of 8 characters + '.' + 3 "
693 	    "characters). The path is not recorded. Stipulations on audio "
694 	    "and file naming conventions are defined in the specification. "
695 	    "When using this tag, audio files must be recorded in "
696 	    "conformance to the Exif audio format. Writers are also allowed "
697 	    "to store the data such as Audio within APP2 as FlashPix "
698 	    "extension stream data. "
699 	    "The mapping of Exif image files and audio files is done "
700 	    "in any of three ways, [1], [2] and [3]. If multiple files "
701 	    "are mapped to one file as in [2] or [3], the above "
702 	    "format is used to record just one audio file name. If "
703 	    "there are multiple audio files, the first recorded file is "
704 	    "given. In the case of [3], for example, for the "
705 	    "Exif image file \"DSC00001.JPG\" only  \"SND00001.WAV\" is "
706 	    "given as the related Exif audio file. When there are three "
707 	    "Exif audio files \"SND00001.WAV\", \"SND00002.WAV\" and "
708 	    "\"SND00003.WAV\", the Exif image file name for each of them, "
709 	    "\"DSC00001.JPG\", is indicated. By combining multiple "
710 	    "relational information, a variety of playback possibilities "
711 	    "can be supported. The method of using relational information "
712 	    "is left to the implementation on the playback side. Since this "
713 	    "information is an ASCII character string, it is terminated by "
714 	    "NULL. When this tag is used to map audio files, the relation "
715 	    "of the audio file to image data must also be indicated on the "
716 	    "audio file end."),
717 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
718 	{EXIF_TAG_INTEROPERABILITY_IFD_POINTER, "InteroperabilityIFDPointer",
719 	 N_("Interoperability IFD Pointer"),
720 	 N_("Interoperability IFD is composed of tags which stores the "
721 	    "information to ensure the Interoperability and pointed "
722 	    "by the following tag located in Exif IFD. "
723 	    "The Interoperability structure of Interoperability IFD is "
724 	    "the same as TIFF defined IFD structure "
725 	    "but does not contain the "
726 	    "image data characteristically compared with normal TIFF "
727 	    "IFD."),
728 	 { ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN, ESL_NNNN } },
729 	{EXIF_TAG_FLASH_ENERGY, "FlashEnergy", N_("Flash Energy"),
730 	 N_("Indicates the strobe energy at the time the image is "
731 	    "captured, as measured in Beam Candle Power Seconds (BCPS)."),
732 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
733 	{EXIF_TAG_SPATIAL_FREQUENCY_RESPONSE, "SpatialFrequencyResponse",
734 	 N_("Spatial Frequency Response"),
735 	 N_("This tag records the camera or input device spatial frequency "
736 	    "table and SFR values in the direction of image width, "
737 	    "image height, and diagonal direction, as specified in ISO "
738 	    "12233."),
739 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
740 	{EXIF_TAG_FOCAL_PLANE_X_RESOLUTION, "FocalPlaneXResolution",
741 	 N_("Focal Plane X-Resolution"),
742 	 N_("Indicates the number of pixels in the image width (X) direction "
743 	    "per <FocalPlaneResolutionUnit> on the camera focal plane."),
744 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
745 	{EXIF_TAG_FOCAL_PLANE_Y_RESOLUTION, "FocalPlaneYResolution",
746 	 N_("Focal Plane Y-Resolution"),
747 	 N_("Indicates the number of pixels in the image height (V) direction "
748 	    "per <FocalPlaneResolutionUnit> on the camera focal plane."),
749 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
750 	{EXIF_TAG_FOCAL_PLANE_RESOLUTION_UNIT, "FocalPlaneResolutionUnit",
751 	 N_("Focal Plane Resolution Unit"),
752 	 N_("Indicates the unit for measuring <FocalPlaneXResolution> and "
753 	    "<FocalPlaneYResolution>. This value is the same as the "
754 	    "<ResolutionUnit>."),
755 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
756 	{EXIF_TAG_SUBJECT_LOCATION, "SubjectLocation",
757 	 N_("Subject Location"),
758 	 N_("Indicates the location of the main subject in the scene. The "
759 	    "value of this tag represents the pixel at the center of the "
760 	    "main subject relative to the left edge, prior to rotation "
761 	    "processing as per the <Rotation> tag. The first value "
762 	    "indicates the X column number and the second indicates "
763 	    "the Y row number."),
764 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
765 	{EXIF_TAG_EXPOSURE_INDEX, "ExposureIndex", N_("Exposure Index"),
766 	 N_("Indicates the exposure index selected on the camera or "
767 	    "input device at the time the image is captured."),
768 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
769 	{EXIF_TAG_SENSING_METHOD, "SensingMethod", N_("Sensing Method"),
770 	 N_("Indicates the image sensor type on the camera or input "
771 	    "device."),
772 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
773 	{EXIF_TAG_FILE_SOURCE, "FileSource", N_("File Source"),
774 	 N_("Indicates the image source. If a DSC recorded the image, "
775 	    "the tag value of this tag always be set to 3, indicating "
776 	    "that the image was recorded on a DSC."),
777 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
778 	{EXIF_TAG_SCENE_TYPE, "SceneType", N_("Scene Type"),
779 	 N_("Indicates the type of scene. If a DSC recorded the image, "
780 	    "this tag value must always be set to 1, indicating that the "
781 	    "image was directly photographed."),
782 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
783 	{EXIF_TAG_NEW_CFA_PATTERN, "CFAPattern",
784 	 N_("CFA Pattern"),
785 	 N_("Indicates the color filter array (CFA) geometric pattern of the "
786 	    "image sensor when a one-chip color area sensor is used. "
787 	    "It does not apply to all sensing methods."),
788 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
789 	{EXIF_TAG_CUSTOM_RENDERED, "CustomRendered", N_("Custom Rendered"),
790 	 N_("This tag indicates the use of special processing on image "
791 	    "data, such as rendering geared to output. When special "
792 	    "processing is performed, the reader is expected to disable "
793 	    "or minimize any further processing."),
794 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
795 	{EXIF_TAG_EXPOSURE_MODE, "ExposureMode", N_("Exposure Mode"),
796 	 N_("This tag indicates the exposure mode set when the image was "
797 	    "shot. In auto-bracketing mode, the camera shoots a series of "
798 	    "frames of the same scene at different exposure settings."),
799 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
800 	{EXIF_TAG_WHITE_BALANCE, "WhiteBalance", N_("White Balance"),
801 	 N_("This tag indicates the white balance mode set when the image "
802 	    "was shot."),
803 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
804 	{EXIF_TAG_DIGITAL_ZOOM_RATIO, "DigitalZoomRatio",
805 	 N_("Digital Zoom Ratio"),
806 	 N_("This tag indicates the digital zoom ratio when the image was "
807 	    "shot. If the numerator of the recorded value is 0, this "
808 	    "indicates that digital zoom was not used."),
809 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
810 	{EXIF_TAG_FOCAL_LENGTH_IN_35MM_FILM, "FocalLengthIn35mmFilm",
811 	 N_("Focal Length in 35mm Film"),
812 	 N_("This tag indicates the equivalent focal length assuming a "
813 	    "35mm film camera, in mm. A value of 0 means the focal "
814 	    "length is unknown. Note that this tag differs from the "
815 	    "FocalLength tag."),
816 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
817 	{EXIF_TAG_SCENE_CAPTURE_TYPE, "SceneCaptureType",
818 	 N_("Scene Capture Type"),
819 	 N_("This tag indicates the type of scene that was shot. It can "
820 	    "also be used to record the mode in which the image was "
821 	    "shot. Note that this differs from the scene type "
822 	    "<SceneType> tag."),
823 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
824 	{EXIF_TAG_GAIN_CONTROL, "GainControl", N_("Gain Control"),
825 	 N_("This tag indicates the degree of overall image gain "
826 	    "adjustment."),
827 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
828 	{EXIF_TAG_CONTRAST, "Contrast", N_("Contrast"),
829 	 N_("This tag indicates the direction of contrast processing "
830 	    "applied by the camera when the image was shot."),
831 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
832 	{EXIF_TAG_SATURATION, "Saturation", N_("Saturation"),
833 	 N_("This tag indicates the direction of saturation processing "
834 	    "applied by the camera when the image was shot."),
835 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
836 	{EXIF_TAG_SHARPNESS, "Sharpness", N_("Sharpness"),
837 	 N_("This tag indicates the direction of sharpness processing "
838 	    "applied by the camera when the image was shot."),
839 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
840 	{EXIF_TAG_DEVICE_SETTING_DESCRIPTION, "DeviceSettingDescription",
841 	 N_("Device Setting Description"),
842 	 N_("This tag indicates information on the picture-taking "
843 	    "conditions of a particular camera model. The tag is used "
844 	    "only to indicate the picture-taking conditions in the "
845 	    "reader."),
846 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
847 	{EXIF_TAG_SUBJECT_DISTANCE_RANGE, "SubjectDistanceRange",
848 	 N_("Subject Distance Range"),
849 	 N_("This tag indicates the distance to the subject."),
850 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
851 	{EXIF_TAG_IMAGE_UNIQUE_ID, "ImageUniqueID", N_("Image Unique ID"),
852 	 N_("This tag indicates an identifier assigned uniquely to "
853 	    "each image. It is recorded as an ASCII string equivalent "
854 	    "to hexadecimal notation and 128-bit fixed length."),
855 	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
856 	/* Not in EXIF 2.2 */
857 	{EXIF_TAG_GAMMA, "Gamma", N_("Gamma"),
858 	 N_("Indicates the value of coefficient gamma.")},
859 	/* Not in EXIF 2.2 */
860 	{EXIF_TAG_PRINT_IMAGE_MATCHING, "PrintImageMatching", N_("PRINT Image Matching"),
861 	 N_("Related to Epson's PRINT Image Matching technology")},
862 	/* Not in EXIF 2.2 (from the Microsoft HD Photo specification) */
863 	{EXIF_TAG_PADDING, "Padding", N_("Padding"),
864 	 N_("This tag reserves space that can be reclaimed later when "
865             "additional metadata are added. New metadata can be written "
866             "in place by replacing this tag with a smaller data element "
867             "and using the reclaimed space to store the new or expanded "
868             "metadata tags."),
869 	 { ESL_OOOO, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
870 #endif
871 	{0, NULL, NULL, NULL}
872 };
873 
874 /* For now, do not use these functions. */
875 
876 /*!
877  * Return the number of entries in the EXIF tag table, including the
878  * terminating NULL entry.
879  */
880 inline unsigned int
exif_tag_table_count(void)881 exif_tag_table_count (void)
882 {
883 	return sizeof (ExifTagTable) / sizeof (ExifTagTable[0]);
884 }
885 
886 
887 ExifTag
exif_tag_table_get_tag(unsigned int n)888 exif_tag_table_get_tag (unsigned int n)
889 {
890 	return (n < exif_tag_table_count ()) ? ExifTagTable[n].tag : 0;
891 }
892 
893 const char *
exif_tag_table_get_name(unsigned int n)894 exif_tag_table_get_name (unsigned int n)
895 {
896 	return (n < exif_tag_table_count ()) ? ExifTagTable[n].name : NULL;
897 }
898 
899 /*!
900  * Compares the tag with that in entry.
901  * \param[in] tag pointer to integer tag value
902  * \param[in] entry pointer to a struct TagEntry
903  * \return 0 if tags are equal, <0 if tag < entry, >0 if tag > entry
904  */
905 static int
match_tag(const void * tag,const void * entry)906 match_tag(const void *tag, const void *entry)
907 {
908 	return *(int*)tag - ((struct TagEntry *)entry)->tag;
909 }
910 
911 
912 /*!
913  * Finds the first entry in the EXIF tag table with the given tag number
914  * using a binary search.
915  * \param[in] tag to find
916  * \return index into table, or -1 if not found
917  */
918 static int
exif_tag_table_first(ExifTag tag)919 exif_tag_table_first(ExifTag tag)
920 {
921 	int i;
922 	struct TagEntry *entry = bsearch(&tag, ExifTagTable,
923 		exif_tag_table_count()-1, sizeof(struct TagEntry), match_tag);
924 	if (!entry)
925 		return -1;	/* Not found */
926 
927 	/* Calculate index of found entry */
928 	i = entry - ExifTagTable;
929 
930 	/* There may be other entries with the same tag number, so search
931 	 * backwards to find the first
932 	 */
933 	while ((i > 0) && (ExifTagTable[i-1].tag == tag)) {
934 		--i;
935 	}
936 	return i;
937 }
938 
939 #define RECORDED \
940 ((ExifTagTable[i].esl[ifd][EXIF_DATA_TYPE_UNCOMPRESSED_CHUNKY] != EXIF_SUPPORT_LEVEL_NOT_RECORDED) || \
941  (ExifTagTable[i].esl[ifd][EXIF_DATA_TYPE_UNCOMPRESSED_PLANAR] != EXIF_SUPPORT_LEVEL_NOT_RECORDED) || \
942  (ExifTagTable[i].esl[ifd][EXIF_DATA_TYPE_UNCOMPRESSED_YCC] != EXIF_SUPPORT_LEVEL_NOT_RECORDED) || \
943  (ExifTagTable[i].esl[ifd][EXIF_DATA_TYPE_COMPRESSED] != EXIF_SUPPORT_LEVEL_NOT_RECORDED))
944 
945 const char *
exif_tag_get_name_in_ifd(ExifTag tag,ExifIfd ifd)946 exif_tag_get_name_in_ifd (ExifTag tag, ExifIfd ifd)
947 {
948 	unsigned int i;
949 	int first;
950 
951 	if (ifd >= EXIF_IFD_COUNT)
952 		return NULL;
953 	first = exif_tag_table_first(tag);
954 	if (first < 0)
955 		return NULL;
956 
957 	for (i = first; ExifTagTable[i].name; i++) {
958 		if (ExifTagTable[i].tag == tag) {
959 		   if (RECORDED)
960 			   break;
961 		} else
962 			return NULL; /* Recorded tag not found in the table */
963 	}
964 	return ExifTagTable[i].name;
965 }
966 
967 const char *
exif_tag_get_title_in_ifd(ExifTag tag,ExifIfd ifd)968 exif_tag_get_title_in_ifd (ExifTag tag, ExifIfd ifd)
969 {
970 	unsigned int i;
971 	int first;
972 
973 	if (ifd >= EXIF_IFD_COUNT)
974 		return NULL;
975 	first = exif_tag_table_first(tag);
976 	if (first < 0)
977 		return NULL;
978 
979 	for (i = first; ExifTagTable[i].name; i++) {
980 		if (ExifTagTable[i].tag == tag) {
981 		   if (RECORDED)
982 			   break;
983 		} else
984 			return NULL; /* Recorded tag not found in the table */
985 	}
986 	/* FIXME: This belongs to somewhere else. */
987 	/* libexif should use the default system locale.
988 	 * If an application specifically requires UTF-8, then we
989 	 * must give the application a way to tell libexif that.
990 	 *
991 	 * bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
992 	 */
993 	bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR);
994 	return _(ExifTagTable[i].title);
995 }
996 
997 const char *
exif_tag_get_description_in_ifd(ExifTag tag,ExifIfd ifd)998 exif_tag_get_description_in_ifd (ExifTag tag, ExifIfd ifd)
999 {
1000 	unsigned int i;
1001 	int first;
1002 
1003 	if (ifd >= EXIF_IFD_COUNT)
1004 		return NULL;
1005 	first = exif_tag_table_first(tag);
1006 	if (first < 0)
1007 		return NULL;
1008 
1009 	for (i = first; ExifTagTable[i].name; i++) {
1010 		if (ExifTagTable[i].tag == tag) {
1011 			if (RECORDED)
1012 				break;
1013 		} else
1014 			return NULL; /* Recorded tag not found in the table */
1015 	}
1016 
1017 	/* GNU gettext acts strangely when given an empty string */
1018 	if (!ExifTagTable[i].description || !*ExifTagTable[i].description)
1019 		return "";
1020 
1021 	/* libexif should use the default system locale.
1022 	 * If an application specifically requires UTF-8, then we
1023 	 * must give the application a way to tell libexif that.
1024 	 *
1025 	 * bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
1026 	 */
1027 	bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR);
1028 	return _(ExifTagTable[i].description);
1029 }
1030 
1031 
1032 /**********************************************************************
1033  * convenience functions
1034  **********************************************************************/
1035 
1036 /* generic part: iterate through IFD list and return first result */
1037 typedef const char * (*get_stuff_func) (ExifTag tag, ExifIfd ifd);
1038 
1039 static const char *
exif_tag_get_stuff(ExifTag tag,get_stuff_func func)1040 exif_tag_get_stuff (ExifTag tag, get_stuff_func func)
1041 {
1042 	/* Search IFDs in this order, in decreasing order of number of valid tags */
1043 	static const ExifIfd ifds[EXIF_IFD_COUNT] = {
1044 		EXIF_IFD_EXIF,
1045 		EXIF_IFD_0,
1046 		EXIF_IFD_1,
1047 		EXIF_IFD_INTEROPERABILITY,
1048 		EXIF_IFD_GPS
1049 	};
1050 	int i;
1051 	for (i=0; i<EXIF_IFD_COUNT; i++) {
1052 		const char *result = func(tag, ifds[i]);
1053 		if (result != NULL) {
1054 			return result;
1055 		}
1056 	}
1057 	return (const char *) NULL;
1058 }
1059 
1060 /* explicit functions */
1061 const char *
exif_tag_get_name(ExifTag tag)1062 exif_tag_get_name (ExifTag tag)
1063 {
1064 	return exif_tag_get_stuff(tag, exif_tag_get_name_in_ifd);
1065 }
1066 
1067 const char *
exif_tag_get_title(ExifTag tag)1068 exif_tag_get_title (ExifTag tag)
1069 {
1070 	return exif_tag_get_stuff(tag, exif_tag_get_title_in_ifd);
1071 }
1072 
1073 const char *
exif_tag_get_description(ExifTag tag)1074 exif_tag_get_description (ExifTag tag)
1075 {
1076 	return exif_tag_get_stuff(tag, exif_tag_get_description_in_ifd);
1077 }
1078 
1079 
1080 
1081 ExifTag
exif_tag_from_name(const char * name)1082 exif_tag_from_name (const char *name)
1083 {
1084 	unsigned int i;
1085 	unsigned int result=0;
1086 
1087 	if (!name) return 0;
1088 
1089 	for (i = 0; ExifTagTable[i].name; i++)
1090 		if (!strcmp (ExifTagTable[i].name, name))  {
1091 		  	result = ExifTagTable[i].tag;
1092 		  	break;
1093 		}
1094 	return result;
1095 }
1096 
1097 /*! Return the support level of a tag in the given IFD with the given data
1098  * type. If the tag is not specified in the EXIF standard, this function
1099  * returns EXIF_SUPPORT_LEVEL_NOT_RECORDED.
1100  *
1101  * \param[in] tag EXIF tag
1102  * \param[in] ifd a valid IFD (not EXIF_IFD_COUNT)
1103  * \param[in] t a valid data type (not EXIF_DATA_TYPE_UNKNOWN)
1104  * \return the level of support for this tag
1105  */
1106 static inline ExifSupportLevel
get_support_level_in_ifd(ExifTag tag,ExifIfd ifd,ExifDataType t)1107 get_support_level_in_ifd (ExifTag tag, ExifIfd ifd, ExifDataType t)
1108 {
1109 	unsigned int i;
1110 	int first = exif_tag_table_first(tag);
1111 	if (first < 0)
1112 		return EXIF_SUPPORT_LEVEL_NOT_RECORDED;
1113 
1114 	for (i = first; ExifTagTable[i].name; i++) {
1115 		if (ExifTagTable[i].tag == tag) {
1116 			const ExifSupportLevel supp = ExifTagTable[i].esl[ifd][t];
1117 			if (supp != EXIF_SUPPORT_LEVEL_NOT_RECORDED)
1118 				return supp;
1119 			/* Try looking for another entry */
1120 		} else {
1121 			break; /* We've reached the end of the matching tags */
1122 		}
1123 	}
1124 	return EXIF_SUPPORT_LEVEL_NOT_RECORDED;
1125 }
1126 
1127 /*! Return the support level of a tag in the given IFD, regardless of the
1128  * data type. If the support level varies depending on the data type, this
1129  * function returns EXIF_SUPPORT_LEVEL_UNKNOWN. If the tag is not specified
1130  * in the EXIF standard, this function returns EXIF_SUPPORT_LEVEL_UNKNOWN.
1131  *
1132  * \param[in] tag EXIF tag
1133  * \param[in] ifd a valid IFD (not EXIF_IFD_COUNT)
1134  * \return the level of support for this tag
1135  */
1136 static inline ExifSupportLevel
get_support_level_any_type(ExifTag tag,ExifIfd ifd)1137 get_support_level_any_type (ExifTag tag, ExifIfd ifd)
1138 {
1139 	unsigned int i;
1140 	int first = exif_tag_table_first(tag);
1141 	if (first < 0)
1142 		return EXIF_SUPPORT_LEVEL_UNKNOWN;
1143 
1144 	for (i = first; ExifTagTable[i].name; i++) {
1145 		if (ExifTagTable[i].tag == tag) {
1146 			/*
1147 			 * Check whether the support level is the same for all possible
1148 			 * data types and isn't marked not recorded.
1149 			 */
1150 			const ExifSupportLevel supp = ExifTagTable[i].esl[ifd][0];
1151 			/* If level is not recorded, keep searching for another */
1152 			if (supp != EXIF_SUPPORT_LEVEL_NOT_RECORDED) {
1153 				unsigned int dt;
1154 				for (dt = 0; dt < EXIF_DATA_TYPE_COUNT; ++dt) {
1155 					if (ExifTagTable[i].esl[ifd][dt] != supp)
1156 						break;
1157 				}
1158 				if (dt == EXIF_DATA_TYPE_COUNT)
1159 					/* Support level is always the same, so return it */
1160 					return supp;
1161 			}
1162 			/* Keep searching the table for another tag for our IFD */
1163 		} else {
1164 			break; /* We've reached the end of the matching tags */
1165 		}
1166 	}
1167 	return EXIF_SUPPORT_LEVEL_UNKNOWN;
1168 }
1169 
1170 ExifSupportLevel
exif_tag_get_support_level_in_ifd(ExifTag tag,ExifIfd ifd,ExifDataType t)1171 exif_tag_get_support_level_in_ifd (ExifTag tag, ExifIfd ifd, ExifDataType t)
1172 {
1173 	if (ifd >= EXIF_IFD_COUNT)
1174 		return EXIF_SUPPORT_LEVEL_UNKNOWN;
1175 
1176 	if (t >= EXIF_DATA_TYPE_COUNT)
1177 		return get_support_level_any_type (tag, ifd);
1178 
1179 	return get_support_level_in_ifd (tag, ifd, t);
1180 }
1181