-/* exif-entry.h
- *
- * Copyright (C) 2001 Lutz Müller <lutz@users.sourceforge.net>
+/*! \file exif-entry.h
+ * \brief Handling EXIF entries
+ */
+/*
+ * Copyright (c) 2001 Lutz Mueller <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
*
* 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.
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
*/
#ifndef __EXIF_ENTRY_H__
extern "C" {
#endif /* __cplusplus */
+/*! Data found in one EXIF tag.
+ * The #exif_entry_get_value function can provide access to the
+ * formatted contents, or the struct members can be used directly to
+ * access the raw contents.
+ */
typedef struct _ExifEntry ExifEntry;
typedef struct _ExifEntryPrivate ExifEntryPrivate;
#include <libexif/exif-content.h>
#include <libexif/exif-format.h>
+#include <libexif/exif-mem.h>
+/*! Data found in one EXIF tag */
struct _ExifEntry {
+ /*! EXIF tag for this entry */
ExifTag tag;
+
+ /*! Type of data in this entry */
ExifFormat format;
+
+ /*! Number of elements in the array, if this is an array entry.
+ * Contains 1 for non-array data types. */
unsigned long components;
+ /*! Pointer to the raw EXIF data for this entry. It is allocated
+ * by #exif_entry_initialize and is NULL beforehand. Data contained
+ * here may be manipulated using the functions in exif-utils.h */
unsigned char *data;
+
+ /*! Number of bytes in the buffer at \c data. This must be no less
+ * than exif_format_get_size(format)*components */
unsigned int size;
- /* Content containing this entry */
+ /*! #ExifContent containing this entry.
+ * \see exif_entry_get_ifd */
ExifContent *parent;
+ /*! Internal data to be used by libexif itself */
ExifEntryPrivate *priv;
};
/* Lifecycle */
-ExifEntry *exif_entry_new (void);
-void exif_entry_ref (ExifEntry *entry);
-void exif_entry_unref (ExifEntry *entry);
+
+/*! Reserve memory for and initialize a new #ExifEntry.
+ * No memory is allocated for the \c data element of the returned #ExifEntry.
+ *
+ * \return new allocated #ExifEntry, or NULL on error
+ *
+ * \see exif_entry_new_mem, exif_entry_unref
+ */
+ExifEntry *exif_entry_new (void);
+
+/*! Reserve memory for and initialize new #ExifEntry using the specified
+ * memory allocator.
+ * No memory is allocated for the \c data element of the returned #ExifEntry.
+ *
+ * \return new allocated #ExifEntry, or NULL on error
+ *
+ * \see exif_entry_new, exif_entry_unref
+ */
+ExifEntry *exif_entry_new_mem (ExifMem *);
+
+/*! Increase reference counter for #ExifEntry.
+ *
+ * \param[in] entry #ExifEntry
+ *
+ * \see exif_entry_unref
+ */
+void exif_entry_ref (ExifEntry *entry);
+
+/*! Decrease reference counter for #ExifEntry.
+ * When the reference count drops to zero, free the entry.
+ *
+ * \param[in] entry #ExifEntry
+ */
+void exif_entry_unref (ExifEntry *entry);
+
+/*! Actually free the #ExifEntry.
+ *
+ * \deprecated Should not be called directly. Use #exif_entry_ref and
+ * #exif_entry_unref instead.
+ *
+ * \param[in] entry EXIF entry
+ */
void exif_entry_free (ExifEntry *entry);
-void exif_entry_initialize (ExifEntry *entry, ExifTag tag);
+/*! Initialize an empty #ExifEntry with default data in the correct format
+ * for the given tag. If the entry is already initialized, this function
+ * does nothing.
+ * This call allocates memory for the \c data element of the given #ExifEntry.
+ * That memory is freed at the same time as the #ExifEntry.
+ *
+ * \param[out] e entry to initialize
+ * \param[in] tag tag number to initialize as
+ */
+void exif_entry_initialize (ExifEntry *e, ExifTag tag);
+
+/*! Fix the type or format of the given EXIF entry to bring it into spec.
+ * If the data for this EXIF tag is in of the wrong type or is in an invalid
+ * format according to the EXIF specification, then it is converted to make it
+ * valid. This may involve, for example, converting an EXIF_FORMAT_LONG into a
+ * EXIF_FORMAT_SHORT. If the tag is unknown, its value is untouched.
+ *
+ * \note Unfortunately, some conversions are to a type with a more restricted
+ * range, which could have the side effect that the converted data becomes
+ * invalid. This is unlikely as the range of each tag in the standard is
+ * designed to encompass all likely data.
+ *
+ * \param[in,out] entry EXIF entry
+ */
+void exif_entry_fix (ExifEntry *entry);
+
/* For your convenience */
-const char *exif_entry_get_value (ExifEntry *entry);
-const char *exif_entry_get_value_brief (ExifEntry *entry);
+/*! Return a localized textual representation of the value of the EXIF entry.
+ * This is meant for display to the user. The format of each tag is subject
+ * to change between locales and in newer versions of libexif. Users who
+ * require the tag data in an unambiguous form should access the data members
+ * of the #ExifEntry structure directly.
+ *
+ * \warning The character set of the returned string may be in
+ * the encoding of the current locale or the native encoding
+ * of the camera.
+ * \bug The EXIF_TAG_XP_* tags are currently always returned in UTF-8,
+ * regardless of locale, and code points above U+FFFF are not
+ * supported.
+ *
+ * \param[in] entry EXIF entry
+ * \param[out] val buffer in which to store value
+ * \param[in] maxlen length of the buffer val
+ * \return val pointer
+ */
+const char *exif_entry_get_value (ExifEntry *entry, char *val,
+ unsigned int maxlen);
+
+/*! Dump text representation of #ExifEntry to stdout.
+ * This is intended for diagnostic purposes only.
+ *
+ * \param[in] entry EXIF tag data
+ * \param[in] indent how many levels deep to indent the data
+ */
void exif_entry_dump (ExifEntry *entry, unsigned int indent);
+/*! Return the IFD number of the given #ExifEntry
+ *
+ * \param[in] e an #ExifEntry*
+ * \return #ExifIfd, or #EXIF_IFD_COUNT on error
+ */
+#define exif_entry_get_ifd(e) ((e)?exif_content_get_ifd((e)->parent):EXIF_IFD_COUNT)
+
#ifdef __cplusplus
}
#endif /* __cplusplus */
projects / platform / upstream / libexif.git / blobdiff