EXIF library (libexif) API 0.6.22
exif-entry.h File Reference

Handling EXIF entries. More...

#include <libexif/exifcont.h>
#include <libexif/exifform.h>
#include <libexif/exifmem.h>

Go to the source code of this file.

Data Structures

struct  _ExifEntry
 Data found in one EXIF tag. More...
 

Macros

#define exif_entry_get_ifd(e)   ((e) ? exif_content_get_ifd((e)->parent) : EXIF_IFD_COUNT)
 Return the IFD number of the given ExifEntry.
 

Typedefs

typedef struct _ExifEntry ExifEntry
 Data found in one EXIF tag.
 
typedef struct _ExifEntryPrivate ExifEntryPrivate
 

Functions

 EXIF_API (ExifEntry *) exif_entry_new(void)
 Reserve memory for and initialize a new ExifEntry.
 
 EXIF_API (void) exif_entry_ref(ExifEntry *entry)
 Increase reference counter for ExifEntry.
 
 EXIF_API (const char *) exif_entry_get_value(ExifEntry *entry
 Return a localized textual representation of the value of the EXIF entry.
 

Variables

ExifTag tag
 
char * val
 
char uint32_t maxlen
 
exif_uint_t indent
 

Detailed Description

Handling EXIF entries.

Macro Definition Documentation

◆ exif_entry_get_ifd

#define exif_entry_get_ifd (   e)    ((e) ? exif_content_get_ifd((e)->parent) : EXIF_IFD_COUNT)

Return the IFD number of the given ExifEntry.

Parameters
[in]ean ExifEntry*
Returns
ExifIfd, or EXIF_IFD_COUNT on error

Typedef Documentation

◆ ExifEntry

typedef struct _ExifEntry ExifEntry

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.

Function Documentation

◆ EXIF_API() [1/3]

EXIF_API ( const char *  )

Return a localized textual representation of the value of the EXIF entry.

Return a textual description of the given class of error log.

Return a textual name of the given IFD.

Return a textual representation of the given EXIF data type.

Return a short textual description of the given ExifDataOption.

Return a short, localized, textual name for the given byte order.

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.
Parameters
[in]entryEXIF entry
[out]valbuffer in which to store value; if entry is valid and maxlen > 0 then this string will be NUL-terminated
[in]maxlenlength of the buffer val
Returns
val pointer

◆ EXIF_API() [2/3]

EXIF_API ( ExifEntry )

Reserve memory for and initialize a new ExifEntry.

Reserve memory for and initialize new ExifEntry using the specified memory allocator.

No memory is allocated for the data element of the returned ExifEntry.

Returns
new allocated ExifEntry, or NULL on error
See also
exif_entry_new_mem, exif_entry_unref

No memory is allocated for the data element of the returned ExifEntry.

Returns
new allocated ExifEntry, or NULL on error
See also
exif_entry_new, exif_entry_unref

Reserve memory for and initialize a new ExifEntry.

Reserve memory for and initialize new ExifEntry using the specified memory allocator.

This is a pointer into a member of the ExifContent array and must NOT be freed or unrefed by the caller.

Parameters
[in]contentEXIF content for an IFD
[in]tagEXIF tag to return
Returns
ExifEntry of the tag, or NULL on error

No memory is allocated for the data element of the returned ExifEntry.

Returns
new allocated ExifEntry, or NULL on error
See also
exif_entry_new, exif_entry_unref

Reserve memory for and initialize a new ExifEntry.

This is a pointer into a member of the ExifContent array and must NOT be freed or unrefed by the caller.

Parameters
[in]contentEXIF content for an IFD
[in]tagEXIF tag to return
Returns
ExifEntry of the tag, or NULL on error

◆ EXIF_API() [3/3]

EXIF_API ( void  )

Increase reference counter for ExifEntry.

Dump text representation of ExifEntry to stdout.

Fix the type or format of the given EXIF entry to bring it into spec.

Initialize an empty ExifEntry with default data in the correct format for the given tag.

Actually free the ExifEntry.

Decrease reference counter for ExifEntry.

Parameters
[in]entryExifEntry
See also
exif_entry_unref

When the reference count drops to zero, free the entry.

Parameters
[in]entryExifEntry
Deprecated:
Should not be called directly. Use exif_entry_ref and exif_entry_unref instead.
Parameters
[in]entryEXIF entry

If the entry is already initialized, this function does nothing. This call allocates memory for the data element of the given ExifEntry. That memory is freed at the same time as the ExifEntry.

Parameters
[out]eentry to initialize
[in]tagtag number to initialize as

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.
Parameters
[in,out]entryEXIF entry

This is intended for diagnostic purposes only.

Parameters
[in]entryEXIF tag data
[in]indenthow many levels deep to indent the data