First commit - moving from LuaForge to SourceForge

1 files changed, 1039 insertions, 0 deletions

diff --git a/src/libexif/exif-data.c b/src/libexif/exif-data.c
new file mode 100644
index 0000000..92e5857
--- /dev/null
+++ b/src/libexif/exif-data.c
@@ -0,0 +1,1039 @@
+/* exif-data.c
+ *
+ * Copyright © 2001 Lutz Müller <lutz@users.sourceforge.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <config.h>
+
+#include <libexif/exif-mnote-data.h>
+#include <libexif/exif-data.h>
+#include <libexif/exif-ifd.h>
+#include <libexif/exif-mnote-data-priv.h>
+#include <libexif/exif-utils.h>
+#include <libexif/exif-loader.h>
+#include <libexif/exif-log.h>
+#include <libexif/i18n.h>
+
+#include <libexif/olympus/exif-mnote-data-olympus.h>
+#include <libexif/canon/exif-mnote-data-canon.h>
+#include <libexif/pentax/exif-mnote-data-pentax.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#undef MAX
+#define MAX(a, b)  (((a) > (b)) ? (a) : (b))
+
+#if defined(__WATCOMC__) || defined(_MSC_VER)
+#      define strncasecmp strnicmp
+#endif
+
+#undef JPEG_MARKER_SOI
+#define JPEG_MARKER_SOI  0xd8
+#undef JPEG_MARKER_APP0
+#define JPEG_MARKER_APP0 0xe0
+#undef JPEG_MARKER_APP1
+#define JPEG_MARKER_APP1 0xe1
+
+static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
+
+struct _ExifDataPrivate
+{
+	ExifByteOrder order;
+
+	ExifMnoteData *md;
+
+	ExifLog *log;
+	ExifMem *mem;
+
+	unsigned int ref_count;
+
+	/* Temporarily used while loading data */
+	unsigned int offset_mnote;
+};
+
+static void *
+exif_data_alloc (ExifData *data, unsigned int i)
+{
+	void *d;
+
+	if (!data || !i) return NULL;
+
+	d = exif_mem_alloc (data->priv->mem, i);
+	if (d) return d;
+
+	EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", i);
+	return NULL;
+}
+
+ExifMnoteData *
+exif_data_get_mnote_data (ExifData *d)
+{
+	return (d && d->priv) ? d->priv->md : NULL;
+}
+
+ExifData *
+exif_data_new (void)
+{
+	ExifMem *mem = exif_mem_new_default ();
+	ExifData *d = exif_data_new_mem (mem);
+
+	exif_mem_unref (mem);
+
+	return d;
+}
+
+ExifData *
+exif_data_new_mem (ExifMem *mem)
+{
+	ExifData *data;
+	unsigned int i;
+
+	if (!mem) return NULL;
+
+	data = exif_mem_alloc (mem, sizeof (ExifData));
+	if (!data) return (NULL);
+	data->priv = exif_mem_alloc (mem, sizeof (ExifDataPrivate));
+	if (!data->priv) { exif_mem_free (mem, data); return (NULL); }
+	data->priv->ref_count = 1;
+
+	data->priv->mem = mem;
+	exif_mem_ref (mem);
+
+	for (i = 0; i < EXIF_IFD_COUNT; i++) {
+		data->ifd[i] = exif_content_new_mem (data->priv->mem);
+		if (!data->ifd[i]) {
+			exif_data_free (data);
+			return (NULL);
+		}
+		data->ifd[i]->parent = data;
+	}
+
+	return (data);
+}
+
+ExifData *
+exif_data_new_from_data (const unsigned char *data, unsigned int size)
+{
+	ExifData *edata;
+
+	edata = exif_data_new ();
+	exif_data_load_data (edata, data, size);
+	return (edata);
+}
+
+static void
+exif_data_load_data_entry (ExifData *data, ExifEntry *entry,
+			   const unsigned char *d,
+			   unsigned int size, unsigned int offset)
+{
+	unsigned int s, doff;
+
+	entry->tag        = exif_get_short (d + offset + 0, data->priv->order);
+	entry->format     = exif_get_short (d + offset + 2, data->priv->order);
+	entry->components = exif_get_long  (d + offset + 4, data->priv->order);
+
+	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+		  "Loading entry 0x%x ('%s')...", entry->tag,
+		  exif_tag_get_name (entry->tag));
+
+	/*
+	 * Size? If bigger than 4 bytes, the actual data is not
+	 * in the entry but somewhere else (offset).
+	 */
+	s = exif_format_get_size (entry->format) * entry->components;
+	if (!s)
+		return;
+	if (s > 4)
+		doff = exif_get_long (d + offset + 8, data->priv->order);
+	else
+		doff = offset + 8;
+
+	/* Sanity check */
+	if (size < doff + s)
+		return;
+
+	entry->data = exif_data_alloc (data, s);
+	if (entry->data) {
+		entry->size = s;
+		memcpy (entry->data, d + doff, s);
+	}
+
+	/* If this is the MakerNote, remember the offset */
+	if (entry->tag == EXIF_TAG_MAKER_NOTE) {
+		if (entry->size > 6) exif_log (data->priv->log,
+			  EXIF_LOG_CODE_DEBUG, "ExifData",
+		          "MakerNote found (%02x %02x %02x %02x "
+			  "%02x %02x %02x...).",
+			  entry->data[0], entry->data[1], entry->data[2],
+			  entry->data[3], entry->data[4], entry->data[5],
+			  entry->data[6]);
+		data->priv->offset_mnote = doff;
+	}
+
+	exif_entry_fix (entry);
+}
+
+static void
+exif_data_save_data_entry (ExifData *data, ExifEntry *e,
+			   unsigned char **d, unsigned int *ds,
+			   unsigned int offset)
+{
+	unsigned int doff, s;
+
+	if (!data || !data->priv) return;
+
+	/*
+	 * Each entry is 12 bytes long. The memory for the entry has
+	 * already been allocated.
+	 */
+	exif_set_short (*d + 6 + offset + 0,
+			data->priv->order, (ExifShort) e->tag);
+	exif_set_short (*d + 6 + offset + 2,
+			data->priv->order, (ExifShort) e->format);
+
+#ifndef EXIF_DONT_CHANGE_MAKER_NOTE
+	/* If this is the maker note tag, update it. */
+	if ((e->tag == EXIF_TAG_MAKER_NOTE) && data->priv->md) {
+		exif_mem_free (data->priv->mem, e->data);
+		e->data = NULL;
+		e->size = 0;
+		exif_mnote_data_set_offset (data->priv->md, *ds - 6);
+		exif_mnote_data_save (data->priv->md, &e->data, &e->size);
+		e->components = e->size;
+	}
+#endif
+
+	exif_set_long  (*d + 6 + offset + 4,
+			data->priv->order, e->components);
+
+	/*
+	 * Size? If bigger than 4 bytes, the actual data is not in
+	 * the entry but somewhere else.
+	 */
+	s = exif_format_get_size (e->format) * e->components;
+	if (s > 4) {
+		doff = *ds - 6;
+		*ds += s;
+
+		/*
+		 * According to the TIFF specification,
+		 * the offset must be an even number. If we need to introduce
+		 * a padding byte, we set it to 0.
+		 */
+		if (s & 1) (*ds)++;
+		*d = exif_mem_realloc (data->priv->mem, *d, *ds);
+		if (!*d) {
+			EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", *ds);
+		  	return;
+		}
+		exif_set_long (*d + 6 + offset + 8, data->priv->order, doff);
+		if (s & 1) *(*d + *ds - 1) = '\0';
+
+	} else
+		doff = offset + 8;
+
+	/* Write the data. Fill unneeded bytes with 0. */
+	memcpy (*d + 6 + doff, e->data, s);
+	if (s < 4) memset (*d + 6 + doff + s, 0, (4 - s));
+}
+
+static void
+exif_data_load_data_thumbnail (ExifData *data, const unsigned char *d,
+			       unsigned int ds, ExifLong offset, ExifLong size)
+{
+	if (ds < offset + size) {
+		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+			  "Bogus thumbnail offset and size: %i < %i + %i.",
+			  (int) ds, (int) offset, (int) size);
+		return;
+	}
+	if (data->data) exif_mem_free (data->priv->mem, data->data);
+	data->size = size;
+	data->data = exif_data_alloc (data, data->size);
+	if (!data->data) return;
+	memcpy (data->data, d + offset, data->size);
+}
+
+#undef CHECK_REC
+#define CHECK_REC(i) 					\
+if (data->ifd[(i)] == ifd) {				\
+	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, \
+		"ExifData", "Recursive entry in IFD "	\
+		"'%s' detected. Skipping...",		\
+		exif_ifd_get_name (i));			\
+	break;						\
+}							\
+if (data->ifd[(i)]->count) {				\
+	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG,	\
+		"ExifData", "Attemt to load IFD "	\
+		"'%s' multiple times detected. "	\
+		"Skipping...",				\
+		exif_ifd_get_name (i));			\
+	break;						\
+}
+
+static void
+exif_data_load_data_content (ExifData *data, ExifContent *ifd,
+			     const unsigned char *d,
+			     unsigned int ds, unsigned int offset)
+{
+	ExifLong o, thumbnail_offset = 0, thumbnail_length = 0;
+	ExifShort n;
+	ExifEntry *entry;
+	unsigned int i;
+	ExifTag tag;
+
+	if (!data || !data->priv) return;
+
+	/* Read the number of entries */
+	if (offset >= ds - 1) return;
+	n = exif_get_short (d + offset, data->priv->order);
+	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+	          "Loading %i entries...", n);
+	offset += 2;
+
+	/* Check if we have enough data. */
+	if (offset + 12 * n > ds) n = (ds - offset) / 12;
+
+	for (i = 0; i < n; i++) {
+
+		tag = exif_get_short (d + offset + 12 * i, data->priv->order);
+		switch (tag) {
+		case EXIF_TAG_EXIF_IFD_POINTER:
+		case EXIF_TAG_GPS_INFO_IFD_POINTER:
+		case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
+		case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
+		case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
+			o = exif_get_long (d + offset + 12 * i + 8,
+					   data->priv->order);
+			switch (tag) {
+			case EXIF_TAG_EXIF_IFD_POINTER:
+				CHECK_REC (EXIF_IFD_EXIF);
+				exif_data_load_data_content (data,
+					data->ifd[EXIF_IFD_EXIF], d, ds, o);
+				break;
+			case EXIF_TAG_GPS_INFO_IFD_POINTER:
+				CHECK_REC (EXIF_IFD_GPS);
+				exif_data_load_data_content (data,
+					data->ifd[EXIF_IFD_GPS], d, ds, o);
+				break;
+			case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
+				CHECK_REC (EXIF_IFD_INTEROPERABILITY);
+				exif_data_load_data_content (data,
+					data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds, o);
+				break;
+			case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
+				thumbnail_offset = o;
+				if (thumbnail_offset && thumbnail_length)
+					exif_data_load_data_thumbnail (data, d,
+						ds, thumbnail_offset,
+						thumbnail_length);
+				break;
+			case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
+				thumbnail_length = o;
+				if (thumbnail_offset && thumbnail_length)
+					exif_data_load_data_thumbnail (data, d,
+						ds, thumbnail_offset,
+						thumbnail_length);
+				break;
+			default:
+				return;
+			}
+			break;
+		default:
+
+			/*
+			 * If we don't know the tag, chances are high
+			 * that the EXIF data does not follow the standard.
+			 */
+			if (!exif_tag_get_name (tag)) {
+				exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+				  "Unknown tag %x (entry %i)", tag, i);
+				return;
+			}
+			entry = exif_entry_new_mem (data->priv->mem);
+			exif_data_load_data_entry (data, entry, d, ds,
+						   offset + 12 * i);
+			exif_content_add_entry (ifd, entry);
+			exif_entry_unref (entry);
+			break;
+		}
+	}
+}
+
+static int
+cmp_func (const unsigned char *p1, const unsigned char *p2, ExifByteOrder o)
+{
+	ExifShort tag1 = exif_get_short (p1, o);
+	ExifShort tag2 = exif_get_short (p2, o);
+
+	return (tag1 < tag2) ? -1 : (tag1 > tag2) ? 1 : 0;
+}
+
+static int
+cmp_func_intel (const void *elem1, const void *elem2)
+{
+	return cmp_func ((const unsigned char *) elem1,
+			(const unsigned char *) elem2, EXIF_BYTE_ORDER_INTEL);
+}
+
+static int
+cmp_func_motorola (const void *elem1, const void *elem2)
+{
+	return cmp_func ((const unsigned char *) elem1,
+			(const unsigned char *) elem2, EXIF_BYTE_ORDER_MOTOROLA);
+}
+
+static void
+exif_data_save_data_content (ExifData *data, ExifContent *ifd,
+			     unsigned char **d, unsigned int *ds,
+			     unsigned int offset)
+{
+	unsigned int j, n_ptr = 0, n_thumb = 0;
+	ExifIfd i;
+
+	if (!data || !data->priv || !ifd || !d || !ds) return;
+
+	for (i = 0; i < EXIF_IFD_COUNT; i++)
+		if (ifd == data->ifd[i])
+			break;
+	if (i == EXIF_IFD_COUNT)
+		return;
+
+	/*
+	 * Check if we need some extra entries for pointers or the thumbnail.
+	 */
+	switch (i) {
+	case EXIF_IFD_0:
+
+		/*
+		 * The pointer to IFD_EXIF is in IFD_0. The pointer to
+		 * IFD_INTEROPERABILITY is in IFD_EXIF.
+		 */
+		if (data->ifd[EXIF_IFD_EXIF]->count ||
+		    data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
+			n_ptr++;
+
+		/* The pointer to IFD_GPS is in IFD_0. */
+		if (data->ifd[EXIF_IFD_GPS]->count)
+			n_ptr++;
+
+		break;
+	case EXIF_IFD_1:
+		if (data->size)
+			n_thumb = 2;
+		break;
+	case EXIF_IFD_EXIF:
+		if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count)
+			n_ptr++;
+	default:
+		break;
+	}
+
+	/*
+	 * Allocate enough memory for all entries
+	 * and the number of entries.
+	 */
+	*ds += (2 + (ifd->count + n_ptr + n_thumb) * 12 + 4);
+	*d = exif_mem_realloc (data->priv->mem, *d, *ds);
+	if (!*d) {
+		EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData", *ds);
+	  	return;
+	}
+
+	/* Save the number of entries */
+	exif_set_short (*d + 6 + offset, data->priv->order,
+			(ExifShort) (ifd->count + n_ptr + n_thumb));
+	offset += 2;
+
+	/* Save each entry */
+	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+		  "Saving %i entries (IFD '%s', offset: %i)...",
+		  ifd->count, exif_ifd_get_name (i), offset);
+	for (j = 0; j < ifd->count; j++)
+		exif_data_save_data_entry (data, ifd->entries[j], d, ds, offset + 12 * j);
+
+	offset += 12 * ifd->count;
+
+	/* Now save special entries. */
+	switch (i) {
+	case EXIF_IFD_0:
+
+		/*
+		 * The pointer to IFD_EXIF is in IFD_0.
+		 * However, the pointer to IFD_INTEROPERABILITY is in IFD_EXIF,
+		 * therefore, if IFD_INTEROPERABILITY is not empty, we need
+		 * IFD_EXIF even if latter is empty.
+		 */
+		if (data->ifd[EXIF_IFD_EXIF]->count ||
+		    data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
+			exif_set_short (*d + 6 + offset + 0, data->priv->order,
+					EXIF_TAG_EXIF_IFD_POINTER);
+			exif_set_short (*d + 6 + offset + 2, data->priv->order,
+					EXIF_FORMAT_LONG);
+			exif_set_long  (*d + 6 + offset + 4, data->priv->order,
+					1);
+			exif_set_long  (*d + 6 + offset + 8, data->priv->order,
+					*ds - 6);
+			exif_data_save_data_content (data,
+				data->ifd[EXIF_IFD_EXIF], d, ds, *ds - 6);
+			offset += 12;
+		}
+
+		/* The pointer to IFD_GPS is in IFD_0, too. */
+		if (data->ifd[EXIF_IFD_GPS]->count) {
+			exif_set_short (*d + 6 + offset + 0, data->priv->order,
+					EXIF_TAG_GPS_INFO_IFD_POINTER);
+			exif_set_short (*d + 6 + offset + 2, data->priv->order,
+					EXIF_FORMAT_LONG);
+			exif_set_long  (*d + 6 + offset + 4, data->priv->order,
+					1);
+			exif_set_long  (*d + 6 + offset + 8, data->priv->order,
+					*ds - 6);
+			exif_data_save_data_content (data,
+				data->ifd[EXIF_IFD_GPS], d, ds, *ds - 6);
+			offset += 12;
+		}
+
+		break;
+	case EXIF_IFD_EXIF:
+
+		/*
+		 * The pointer to IFD_INTEROPERABILITY is in IFD_EXIF.
+		 * See note above.
+		 */
+		if (data->ifd[EXIF_IFD_INTEROPERABILITY]->count) {
+			exif_set_short (*d + 6 + offset + 0, data->priv->order,
+					EXIF_TAG_INTEROPERABILITY_IFD_POINTER);
+			exif_set_short (*d + 6 + offset + 2, data->priv->order,
+					EXIF_FORMAT_LONG);
+			exif_set_long  (*d + 6 + offset + 4, data->priv->order,
+					1);
+			exif_set_long  (*d + 6 + offset + 8, data->priv->order,
+					*ds - 6);
+			exif_data_save_data_content (data,
+				data->ifd[EXIF_IFD_INTEROPERABILITY], d, ds,
+				*ds - 6);
+			offset += 12;
+		}
+
+		break;
+	case EXIF_IFD_1:
+
+		/*
+		 * Information about the thumbnail (if any) is saved in
+		 * IFD_1.
+		 */
+		if (data->size) {
+
+			/* EXIF_TAG_JPEG_INTERCHANGE_FORMAT */
+			exif_set_short (*d + 6 + offset + 0, data->priv->order,
+					EXIF_TAG_JPEG_INTERCHANGE_FORMAT);
+			exif_set_short (*d + 6 + offset + 2, data->priv->order,
+					EXIF_FORMAT_LONG);
+			exif_set_long  (*d + 6 + offset + 4, data->priv->order,
+					1);
+			exif_set_long  (*d + 6 + offset + 8, data->priv->order,
+					*ds - 6);
+			*ds += data->size;
+			*d = exif_mem_realloc (data->priv->mem, *d, *ds);
+			if (!*d) {
+				EXIF_LOG_NO_MEMORY (data->priv->log, "ExifData",
+						    *ds);
+			  	return;
+			}
+			memcpy (*d + *ds - data->size, data->data, data->size);
+			offset += 12;
+
+			/* EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH */
+			exif_set_short (*d + 6 + offset + 0, data->priv->order,
+				EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH);
+			exif_set_short (*d + 6 + offset + 2, data->priv->order,
+					EXIF_FORMAT_LONG);
+			exif_set_long  (*d + 6 + offset + 4, data->priv->order,
+					1);
+			exif_set_long  (*d + 6 + offset + 8, data->priv->order,
+					data->size);
+			offset += 12;
+		}
+
+		break;
+	default:
+		break;
+	}
+
+	/* Sort the directory according to TIFF specification */
+	qsort (*d + 6 + offset - (ifd->count + n_ptr + n_thumb) * 12,
+			(ifd->count + n_ptr + n_thumb), 12,
+			data->priv->order == EXIF_BYTE_ORDER_INTEL ? cmp_func_intel : cmp_func_motorola);
+
+	/* Correctly terminate the directory */
+	if (i == EXIF_IFD_0 && (data->ifd[EXIF_IFD_1]->count ||
+					     data->size)) {
+
+		/*
+		 * We are saving IFD 0. Tell where IFD 1 starts and save
+		 * IFD 1.
+		 */
+		exif_set_long (*d + 6 + offset, data->priv->order, *ds - 6);
+		exif_data_save_data_content (data, data->ifd[EXIF_IFD_1], d, ds,
+					     *ds - 6);
+	} else
+		exif_set_long (*d + 6 + offset, data->priv->order, 0);
+}
+
+typedef enum {
+	EXIF_DATA_TYPE_MAKER_NOTE_NONE		= 0,
+	EXIF_DATA_TYPE_MAKER_NOTE_CANON		= 1,
+	EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS	= 2,
+	EXIF_DATA_TYPE_MAKER_NOTE_PENTAX	= 3
+} ExifDataTypeMakerNote;
+
+static ExifDataTypeMakerNote
+exif_data_get_type_maker_note (ExifData *d)
+{
+	ExifEntry *e, *em;
+	char value[1024];
+
+	if (!d) return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
+	
+	e = exif_data_get_entry (d, EXIF_TAG_MAKER_NOTE);
+        if (!e) return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
+
+	/* Olympus & Nikon */
+	if ((e->size >= 5) && (!memcmp (e->data, "OLYMP", 5) ||
+			       !memcmp (e->data, "Nikon", 5)))
+		return EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS;
+
+	em = exif_data_get_entry (d, EXIF_TAG_MAKE);
+	if (!em) return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
+
+	/* Canon */
+	if (!strcmp (exif_entry_get_value (em, value, sizeof (value)), "Canon"))
+		return EXIF_DATA_TYPE_MAKER_NOTE_CANON;
+
+	/* Pentax & some variant of Nikon */
+	if ((e->size >= 2) && (e->data[0] == 0x00) && (e->data[1] == 0x1b)) {
+		if (!strncasecmp (
+			exif_entry_get_value (em, value, sizeof(value)),
+					      "Nikon", 5))
+			return EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS;
+		else
+			return EXIF_DATA_TYPE_MAKER_NOTE_PENTAX;
+	}
+
+	return EXIF_DATA_TYPE_MAKER_NOTE_NONE;
+}
+
+#define LOG_TOO_SMALL \
+exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifData", \
+		_("Size of data too small to allow for EXIF data."));
+
+void
+exif_data_load_data (ExifData *data, const unsigned char *d_orig,
+		     unsigned int ds_orig)
+{
+	unsigned int l;
+	ExifLong offset;
+	ExifShort n;
+	const unsigned char *d = d_orig;
+	unsigned int ds = ds_orig, len;
+
+	if (!data || !data->priv || !d || !ds) return;
+
+	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+		  "Parsing %i byte(s) EXIF data...\n", ds);
+
+	/*
+	 * It can be that the data starts with the EXIF header. If it does
+	 * not, search the EXIF marker.
+	 */
+	if (ds < 6) {
+		LOG_TOO_SMALL;
+		return;
+	}
+	if (!memcmp (d, ExifHeader, 6)) {
+		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+			  "Found EXIF header.");
+	} else {
+		while (1) {
+			while ((d[0] == 0xff) && ds) {
+				d++;
+				ds--;
+			}
+
+			/* JPEG_MARKER_SOI */
+			if (d[0] == JPEG_MARKER_SOI) {
+				d++;
+				ds--;
+				continue;
+			}
+
+			/* JPEG_MARKER_APP0 */
+			if (d[0] == JPEG_MARKER_APP0) {
+				d++;
+				ds--;
+				l = (d[0] << 8) | d[1];
+				if (l > ds)
+					return;
+				d += l;
+				ds -= l;
+				continue;
+			}
+
+			/* JPEG_MARKER_APP1 */
+			if (d[0] == JPEG_MARKER_APP1)
+				break;
+
+			/* Unknown marker or data. Give up. */
+			exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
+				  "ExifData", _("EXIF marker not found."));
+			return;
+		}
+		d++;
+		ds--;
+		if (ds < 2) {
+			LOG_TOO_SMALL;
+			return;
+		}
+		len = (d[0] << 8) | d[1];
+		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+			  "We have to deal with %i byte(s) of EXIF data.",
+			  len);
+		d += 2;
+		ds -= 2;
+	}
+
+	/*
+	 * Verify the exif header
+	 * (offset 2, length 6).
+	 */
+	if (ds < 6) {
+		LOG_TOO_SMALL;
+		return;
+	}
+	if (memcmp (d, ExifHeader, 6)) {
+		exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
+				"ExifData", _("EXIF header not found."));
+		return;
+	}
+
+	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+		  "Found EXIF header.");
+
+	/* Byte order (offset 6, length 2) */
+	if (ds < 14)
+		return;
+	if (!memcmp (d + 6, "II", 2))
+		data->priv->order = EXIF_BYTE_ORDER_INTEL;
+	else if (!memcmp (d + 6, "MM", 2))
+		data->priv->order = EXIF_BYTE_ORDER_MOTOROLA;
+	else {
+		exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
+				"ExifData", _("Unknown encoding."));
+		return;
+	}
+
+	/* Fixed value */
+	if (exif_get_short (d + 8, data->priv->order) != 0x002a)
+		return;
+
+	/* IFD 0 offset */
+	offset = exif_get_long (d + 10, data->priv->order);
+	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData", 
+		  "IFD 0 at %i.", (int) offset);
+
+	/* Parse the actual exif data (usually offset 14 from start) */
+	exif_data_load_data_content (data, data->ifd[EXIF_IFD_0], d + 6,
+				     ds - 6, offset);
+
+	/* IFD 1 offset */
+	if (offset + 6 + 2 > ds) {
+		return;
+	}
+	n = exif_get_short (d + 6 + offset, data->priv->order);
+	if (offset + 6 + 2 + 12 * n + 4 > ds) {
+		return;
+	}
+	offset = exif_get_long (d + 6 + offset + 2 + 12 * n, data->priv->order);
+	if (offset) {
+		exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+			  "IFD 1 at %i.", (int) offset);
+
+		/* Sanity check. */
+		if (offset > ds - 6) {
+			exif_log (data->priv->log, EXIF_LOG_CODE_CORRUPT_DATA,
+				  "ExifData", "Bogus offset.");
+			return;
+		}
+
+		exif_data_load_data_content (data, data->ifd[EXIF_IFD_1], d + 6,
+					     ds - 6, offset);
+	}
+
+	/*
+	 * If we got an EXIF_TAG_MAKER_NOTE, try to interpret it. Some
+	 * cameras use pointers in the maker note tag that point to the
+	 * space between IFDs. Here is the only place where we have access
+	 * to that data.
+	 */
+	switch (exif_data_get_type_maker_note (data)) {
+	case EXIF_DATA_TYPE_MAKER_NOTE_OLYMPUS:
+		data->priv->md = exif_mnote_data_olympus_new (data->priv->mem);
+		break;
+	case EXIF_DATA_TYPE_MAKER_NOTE_PENTAX:
+		data->priv->md = exif_mnote_data_pentax_new (data->priv->mem);
+		break;
+	case EXIF_DATA_TYPE_MAKER_NOTE_CANON:
+		data->priv->md = exif_mnote_data_canon_new (data->priv->mem);
+		break;
+	default:
+		break;
+	}
+
+	/* 
+	 * If we are able to interpret the maker note, do so.
+	 */
+	if (data->priv->md) {
+		exif_mnote_data_log (data->priv->md, data->priv->log);
+		exif_mnote_data_set_byte_order (data->priv->md,
+						data->priv->order);
+		exif_mnote_data_set_offset (data->priv->md,
+					    data->priv->offset_mnote);
+		exif_mnote_data_load (data->priv->md, d, ds);
+	}
+}
+
+void
+exif_data_save_data (ExifData *data, unsigned char **d, unsigned int *ds)
+{
+	if (!data || !d || !ds)
+		return;
+
+	/* Header */
+	*ds = 14;
+	*d = exif_data_alloc (data, *ds);
+	if (!*d) return;
+	memcpy (*d, ExifHeader, 6);
+
+	/* Order (offset 6) */
+	if (data->priv->order == EXIF_BYTE_ORDER_INTEL) {
+		memcpy (*d + 6, "II", 2);
+	} else {
+		memcpy (*d + 6, "MM", 2);
+	}
+
+	/* Fixed value (2 bytes, offset 8) */
+	exif_set_short (*d + 8, data->priv->order, 0x002a);
+
+	/*
+	 * IFD 0 offset (4 bytes, offset 10).
+	 * We will start 8 bytes after the
+	 * EXIF header (2 bytes for order, another 2 for the test, and
+	 * 4 bytes for the IFD 0 offset make 8 bytes together).
+	 */
+	exif_set_long (*d + 10, data->priv->order, 8);
+
+	/* Now save IFD 0. IFD 1 will be saved automatically. */
+	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+		  "Saving IFDs...");
+	exif_data_save_data_content (data, data->ifd[EXIF_IFD_0], d, ds,
+				     *ds - 6);
+	exif_log (data->priv->log, EXIF_LOG_CODE_DEBUG, "ExifData",
+		  "Saved %i byte(s) EXIF data.", *ds);
+}
+
+ExifData *
+exif_data_new_from_file (const char *path)
+{
+	ExifData *edata;
+	ExifLoader *loader;
+
+	loader = exif_loader_new ();
+	exif_loader_write_file (loader, path);
+	edata = exif_loader_get_data (loader);
+	exif_loader_unref (loader);
+
+	return (edata);
+}
+
+void
+exif_data_ref (ExifData *data)
+{
+	if (!data)
+		return;
+
+	data->priv->ref_count++;
+}
+
+void
+exif_data_unref (ExifData *data)
+{
+	if (!data) return;
+
+	data->priv->ref_count--;
+	if (!data->priv->ref_count) exif_data_free (data);
+}
+
+void
+exif_data_free (ExifData *data)
+{
+	unsigned int i;
+	ExifMem *mem = (data && data->priv) ? data->priv->mem : NULL;
+
+	if (!data) return;
+
+	for (i = 0; i < EXIF_IFD_COUNT; i++) {
+		if (data->ifd[i]) {
+			exif_content_unref (data->ifd[i]);
+			data->ifd[i] = NULL;
+		}
+	}
+
+	if (data->data) {
+		exif_mem_free (mem, data->data);
+		data->data = NULL;
+	}
+
+	if (data->priv) {
+		if (data->priv->log) {
+			exif_log_unref (data->priv->log);
+			data->priv->log = NULL;
+		}
+		if (data->priv->md) {
+			exif_mnote_data_unref (data->priv->md);
+			data->priv->md = NULL;
+		}
+		exif_mem_free (mem, data->priv);
+		exif_mem_free (mem, data);
+	}
+
+	exif_mem_unref (mem);
+}
+
+void
+exif_data_dump (ExifData *data)
+{
+	unsigned int i;
+
+	if (!data)
+		return;
+
+	for (i = 0; i < EXIF_IFD_COUNT; i++) {
+		if (data->ifd[i] && data->ifd[i]->count) {
+			printf ("Dumping IFD '%s'...\n",
+				exif_ifd_get_name (i));
+			exif_content_dump (data->ifd[i], 0);
+		}
+	}
+
+	if (data->data) {
+		printf ("%i byte(s) thumbnail data available.", data->size);
+		if (data->size >= 4) {
+			printf ("0x%02x 0x%02x ... 0x%02x 0x%02x\n",
+				data->data[0], data->data[1],
+				data->data[data->size - 2],
+				data->data[data->size - 1]);
+		}
+	}
+}
+
+ExifByteOrder
+exif_data_get_byte_order (ExifData *data)
+{
+	if (!data)
+		return (0);
+
+	return (data->priv->order);
+}
+
+void
+exif_data_foreach_content (ExifData *data, ExifDataForeachContentFunc func,
+			   void *user_data)
+{
+	unsigned int i;
+
+	if (!data || !func)
+		return;
+
+	for (i = 0; i < EXIF_IFD_COUNT; i++)
+		func (data->ifd[i], user_data);
+}
+
+typedef struct _ByteOrderChangeData ByteOrderChangeData;
+struct _ByteOrderChangeData {
+	ExifByteOrder old, new;
+};
+
+static void
+entry_set_byte_order (ExifEntry *e, void *data)
+{
+	ByteOrderChangeData *d = data;
+
+	if (!e)
+		return;
+
+	exif_array_set_byte_order (e->format, e->data, e->components, d->old, d->new);
+}
+
+static void
+content_set_byte_order (ExifContent *content, void *data)
+{
+	exif_content_foreach_entry (content, entry_set_byte_order, data);
+}
+
+void
+exif_data_set_byte_order (ExifData *data, ExifByteOrder order)
+{
+	ByteOrderChangeData d;
+
+	if (!data || (order == data->priv->order))
+		return;
+
+	d.old = data->priv->order;
+	d.new = order;
+	exif_data_foreach_content (data, content_set_byte_order, &d);
+	data->priv->order = order;
+	if (data->priv->md)
+		exif_mnote_data_set_byte_order (data->priv->md, order);
+}
+
+void
+exif_data_log (ExifData *data, ExifLog *log)
+{
+	unsigned int i;
+
+	if (!data || !data->priv) return;
+	exif_log_unref (data->priv->log);
+	data->priv->log = log;
+	exif_log_ref (log);
+
+	for (i = 0; i < EXIF_IFD_COUNT; i++)
+		exif_content_log (data->ifd[i], log);
+}
+
+/* Used internally within libexif */
+ExifLog *exif_data_get_log (ExifData *);
+ExifLog *
+exif_data_get_log (ExifData *data)
+{
+	if (!data || !data->priv) return NULL;
+	return data->priv->log;
+}