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1 /* exif-content.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-content.h>
24 #include <libexif/exif-system.h>
25 
26 #include <stdlib.h>
27 #include <stdio.h>
28 #include <string.h>
29 
30 /* unused constant
31  * static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
32  */
33 
34 const static unsigned char FOCUS_MODE_AUTO[] = {'A', 'u', 't', 'o'};
35 const static unsigned char FOCUS_MODE_AF_MF[] = {'A', 'F', '_', 'M', 'F'};
36 const static unsigned char FOCUS_MODE_AF_C[] = {'A', 'F', '_', 'C'};
37 const static unsigned char FOCUS_MODE_AF_S[] = {'A', 'F', '_', 'S'};
38 
39 struct _ExifContentPrivate
40 {
41 	unsigned int ref_count;
42 
43 	ExifMem *mem;
44 	ExifLog *log;
45 };
46 
47 ExifContent *
exif_content_new(void)48 exif_content_new (void)
49 {
50 	ExifMem *mem = exif_mem_new_default ();
51 	ExifContent *content = exif_content_new_mem (mem);
52 
53 	exif_mem_unref (mem);
54 
55 	return content;
56 }
57 
58 ExifContent *
exif_content_new_mem(ExifMem * mem)59 exif_content_new_mem (ExifMem *mem)
60 {
61 	ExifContent *content;
62 
63 	if (!mem) return NULL;
64 
65 	content = exif_mem_alloc (mem, (ExifLong) sizeof (ExifContent));
66 	if (!content)
67 		return NULL;
68 	content->priv = exif_mem_alloc (mem,
69 				(ExifLong) sizeof (ExifContentPrivate));
70 	if (!content->priv) {
71 		exif_mem_free (mem, content);
72 		return NULL;
73 	}
74 
75 	content->priv->ref_count = 1;
76 
77 	content->priv->mem = mem;
78 	exif_mem_ref (mem);
79 
80 	return content;
81 }
82 
83 void
exif_content_ref(ExifContent * content)84 exif_content_ref (ExifContent *content)
85 {
86 	if (!content)
87 		return;
88 
89 	content->priv->ref_count++;
90 }
91 
92 void
exif_content_unref(ExifContent * content)93 exif_content_unref (ExifContent *content)
94 {
95 	if (!content || !content->priv)
96 		return;
97 
98 	content->priv->ref_count--;
99 	if (!content->priv->ref_count)
100 		exif_content_free (content);
101 }
102 
103 void
exif_content_free(ExifContent * content)104 exif_content_free (ExifContent *content)
105 {
106 	ExifMem *mem = (content && content->priv) ? content->priv->mem : NULL;
107 	unsigned int i;
108 
109 	if (!content) return;
110 
111 	for (i = 0; i < content->count; i++)
112 		exif_entry_unref (content->entries[i]);
113 	exif_mem_free (mem, content->entries);
114 
115 	if (content->priv) {
116 		exif_log_unref (content->priv->log);
117 	}
118 
119 	exif_mem_free (mem, content->priv);
120 	exif_mem_free (mem, content);
121 	exif_mem_unref (mem);
122 }
123 
124 void
exif_content_dump(ExifContent * content,unsigned int indent)125 exif_content_dump (ExifContent *content, unsigned int indent)
126 {
127 	char buf[1024];
128 	unsigned int i, l;
129 
130 	if (!content)
131 		return;
132 
133 	l = MIN(sizeof(buf)-1, 2*indent);
134 	memset(buf, ' ', l);
135 	buf[l] = '\0';
136 
137 	printf ("%sDumping exif content (%u entries)...\n", buf,
138 		content->count);
139 	for (i = 0; i < content->count; i++)
140 		exif_entry_dump (content->entries[i], indent + 1);
141 }
142 
143 void
exif_content_add_entry(ExifContent * c,ExifEntry * entry)144 exif_content_add_entry (ExifContent *c, ExifEntry *entry)
145 {
146 	ExifEntry **entries;
147 	if (!c || !c->priv || !entry || entry->parent) return;
148 
149 	/* One tag can only be added once to an IFD. */
150 	if (exif_content_get_entry (c, entry->tag) && entry->tag != EXIF_TAG_MAKER_NOTE) {
151 		exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "ExifContent",
152 			"An attempt has been made to add "
153 			"the tag '%s' twice to an IFD. This is against "
154 			"specification.", exif_tag_get_name (entry->tag));
155 		return;
156 	}
157 
158 	/* Add the entry */
159 	if (c->entries) {
160 		entries = exif_mem_realloc (c->priv->mem,
161 			c->entries, sizeof (ExifEntry*) * (c->count + 1));
162 	} else {
163 		entries = exif_mem_alloc (c->priv->mem,
164 			sizeof (ExifEntry*) * (c->count + 1));
165 	}
166 
167 	if (!entries) return;
168 	entry->parent = c;
169 	entries[c->count++] = entry;
170 	c->entries = entries;
171 	exif_entry_ref (entry);
172 }
173 
174 void
exif_content_remove_entry(ExifContent * c,ExifEntry * e)175 exif_content_remove_entry (ExifContent *c, ExifEntry *e)
176 {
177 	unsigned int i;
178 	ExifEntry **t, *temp;
179 
180 	if (!c || !c->priv || !e || (e->parent != c)) return;
181 
182 	/* Search the entry */
183 	for (i = 0; i < c->count; i++)
184 			if (c->entries[i] == e)
185 					break;
186 
187 	if (i == c->count)
188 			return;
189 
190 	/* Remove the entry */
191 	temp = c->entries[c->count-1];
192 	if (c->count > 1) {
193 		t = exif_mem_realloc (c->priv->mem, c->entries,
194 					sizeof(ExifEntry*) * (c->count - 1));
195 		if (!t) {
196 			return;
197 		}
198 		c->entries = t;
199 		c->count--;
200 		if (i != c->count) { /* we deallocated the last slot already */
201 			memmove (&t[i], &t[i + 1], sizeof (ExifEntry*) * (c->count - i - 1));
202 			t[c->count-1] = temp;
203 		}
204 	} else {
205 		exif_mem_free (c->priv->mem, c->entries);
206 		c->entries = NULL;
207 		c->count = 0;
208 	}
209 	e->parent = NULL;
210 	exif_entry_unref (e);
211 }
212 
213 ExifEntry *
exif_content_get_entry(ExifContent * content,ExifTag tag)214 exif_content_get_entry (ExifContent *content, ExifTag tag)
215 {
216 	unsigned int i;
217 
218 	if (!content)
219 		return (NULL);
220 
221 	for (i = 0; i < content->count; i++)
222 		if (content->entries[i]->tag == tag)
223 			return (content->entries[i]);
224 	return (NULL);
225 }
226 
227 ExifEntry *
exif_content_get_entry_ext(ExifContent * content,ExifTag tag)228 exif_content_get_entry_ext (ExifContent *content, ExifTag tag)
229 {
230     if (!content) {
231         return (NULL);
232     }
233     for (unsigned int i = 0; i < content->count; i++) {
234         if (content->entries[i]->tag == tag) {
235             unsigned char* data = content->entries[i]->data;
236             if (tag == EXIF_TAG_MAKER_NOTE && data &&
237                 (!memcmp(data, FOCUS_MODE_AUTO, sizeof(FOCUS_MODE_AUTO) / sizeof(FOCUS_MODE_AUTO[0])) ||
238                 !memcmp(data, FOCUS_MODE_AF_C, sizeof(FOCUS_MODE_AF_C) / sizeof(FOCUS_MODE_AF_C[0])) ||
239                 !memcmp(data, FOCUS_MODE_AF_MF, sizeof(FOCUS_MODE_AF_MF) / sizeof(FOCUS_MODE_AF_MF[0])) ||
240                 !memcmp(data, FOCUS_MODE_AF_S, sizeof(FOCUS_MODE_AF_S) / sizeof(FOCUS_MODE_AF_S[0])))) {
241                 return (content->entries[i]);
242             }
243             continue;
244         }
245     }
246     return (NULL);
247 }
248 
249 ExifEntry *
exif_content_get_huawei_makenote_entry(ExifContent * content)250 exif_content_get_huawei_makenote_entry (ExifContent *content)
251 {
252 	if (!content)
253 		return (NULL);
254 
255 	ExifEntry *entry = NULL;
256 	for (unsigned int i = 0; i < content->count; i++) {
257 		entry = content->entries[i];
258 		if (entry->tag == EXIF_TAG_MAKER_NOTE) {
259 			if (entry->data && (entry->size >= 8) &&
260 				(!memcmp(entry->data, "HUAWEI\0\0", 8))) {
261 				return entry;
262 			}
263 		}
264 	}
265 
266 	return (NULL);
267 }
268 
269 void
exif_content_foreach_entry(ExifContent * content,ExifContentForeachEntryFunc func,void * data)270 exif_content_foreach_entry (ExifContent *content,
271 			    ExifContentForeachEntryFunc func, void *data)
272 {
273 	unsigned int i;
274 
275 	if (!content || !func)
276 		return;
277 
278 	for (i = 0; i < content->count; i++)
279 		func (content->entries[i], data);
280 }
281 
282 void
exif_content_log(ExifContent * content,ExifLog * log)283 exif_content_log (ExifContent *content, ExifLog *log)
284 {
285 	if (!content || !content->priv || !log || content->priv->log == log)
286 		return;
287 
288 	if (content->priv->log) exif_log_unref (content->priv->log);
289 	content->priv->log = log;
290 	exif_log_ref (log);
291 }
292 
293 ExifIfd
exif_content_get_ifd(ExifContent * c)294 exif_content_get_ifd (ExifContent *c)
295 {
296 	if (!c || !c->parent) return EXIF_IFD_COUNT;
297 
298 	return
299 		((c)->parent->ifd[EXIF_IFD_EXIF] == (c)) ? EXIF_IFD_EXIF :
300 		((c)->parent->ifd[EXIF_IFD_0] == (c)) ? EXIF_IFD_0 :
301 		((c)->parent->ifd[EXIF_IFD_1] == (c)) ? EXIF_IFD_1 :
302 		((c)->parent->ifd[EXIF_IFD_GPS] == (c)) ? EXIF_IFD_GPS :
303 		((c)->parent->ifd[EXIF_IFD_INTEROPERABILITY] == (c)) ? EXIF_IFD_INTEROPERABILITY :
304 		EXIF_IFD_COUNT;
305 }
306 
307 static void
fix_func(ExifEntry * e,void * UNUSED (data))308 fix_func (ExifEntry *e, void *UNUSED(data))
309 {
310 	exif_entry_fix (e);
311 }
312 
313 /*!
314  * Check if this entry is unknown and if so, delete it.
315  * \note Be careful calling this function in a loop. Deleting an entry from
316  * an ExifContent changes the index of subsequent entries, as well as the
317  * total size of the entries array.
318  */
319 static void
remove_not_recorded(ExifEntry * e,void * UNUSED (data))320 remove_not_recorded (ExifEntry *e, void *UNUSED(data))
321 {
322 	ExifIfd ifd = exif_entry_get_ifd(e) ;
323 	ExifContent *c = e->parent;
324 	ExifDataType dt = exif_data_get_data_type (c->parent);
325 	ExifTag t = e->tag;
326 
327 	if (exif_tag_get_support_level_in_ifd (t, ifd, dt) ==
328 			 EXIF_SUPPORT_LEVEL_NOT_RECORDED) {
329 		exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "exif-content",
330 				"Tag 0x%04x is not recorded in IFD '%s' and has therefore been "
331 				"removed.", t, exif_ifd_get_name (ifd));
332 		exif_content_remove_entry (c, e);
333 	}
334 
335 }
336 
337 void
exif_content_fix(ExifContent * c)338 exif_content_fix (ExifContent *c)
339 {
340 	ExifIfd ifd = exif_content_get_ifd (c);
341 	ExifDataType dt;
342 	ExifEntry *e;
343 	unsigned int i, num;
344 
345 	if (!c)
346 		return;
347 
348 	dt = exif_data_get_data_type (c->parent);
349 
350 	/*
351 	 * First of all, fix all existing entries.
352 	 */
353 	exif_content_foreach_entry (c, fix_func, NULL);
354 
355 	/*
356 	 * Go through each tag and if it's not recorded, remove it. If one
357 	 * is removed, exif_content_foreach_entry() will skip the next entry,
358 	 * so if this happens do the loop again from the beginning to ensure
359 	 * they're all checked. This could be avoided if we stop relying on
360 	 * exif_content_foreach_entry but loop intelligently here.
361 	 */
362 	do {
363 		num = c->count;
364 		exif_content_foreach_entry (c, remove_not_recorded, NULL);
365 	} while (num != c->count);
366 
367 	/*
368 	 * Then check for non-existing mandatory tags and create them if needed
369 	 */
370 	num = exif_tag_table_count();
371 	for (i = 0; i < num; ++i) {
372 		const ExifTag t = exif_tag_table_get_tag (i);
373 		if (exif_tag_get_support_level_in_ifd (t, ifd, dt) ==
374 			EXIF_SUPPORT_LEVEL_MANDATORY) {
375 			if (exif_content_get_entry (c, t))
376 				/* This tag already exists */
377 				continue;
378 			exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "exif-content",
379 					"Tag '%s' is mandatory in IFD '%s' and has therefore been added.",
380 					exif_tag_get_name_in_ifd (t, ifd), exif_ifd_get_name (ifd));
381 			e = exif_entry_new ();
382 			exif_content_add_entry (c, e);
383 			exif_entry_initialize (e, t);
384 			exif_entry_unref (e);
385 		}
386 	}
387 }
388