exif-content.h File Reference

Handling EXIF IFDs. More...

#include <libexif/exif-tag.h>
#include <libexif/exif-entry.h>
#include <libexif/exif-data.h>
#include <libexif/exif-log.h>
#include <libexif/exif-mem.h>

Go to the source code of this file.

Data Structures
struct	_ExifContent

Macros
#define	exif_content_get_value(c, t, v, m)
	Return a textual representation of the EXIF data for a tag.

Typedefs
typedef struct _ExifContent	ExifContent
	Holds all EXIF tags in a single IFD.
typedef struct _ExifContentPrivate	ExifContentPrivate
typedef void(*	ExifContentForeachEntryFunc) (ExifEntry *, void *user_data)

Functions
ExifContent *	exif_content_new (void)
	Reserve memory for and initialize a new ExifContent.
ExifContent *	exif_content_new_mem (ExifMem *)
	Reserve memory for and initialize new ExifContent using the specified memory allocator.
void	exif_content_ref (ExifContent *content)
	Increase reference counter for ExifContent.
void	exif_content_unref (ExifContent *content)
	Decrease reference counter for ExifContent.
void	exif_content_free (ExifContent *content)
	Actually free the ExifContent.
void	exif_content_add_entry (ExifContent *c, ExifEntry *entry)
	Add an EXIF tag to an IFD.
void	exif_content_remove_entry (ExifContent *c, ExifEntry *e)
	Remove an EXIF tag from an IFD.
ExifEntry *	exif_content_get_entry (ExifContent *content, ExifTag tag)
	Return the ExifEntry in this IFD corresponding to the given tag.
void	exif_content_fix (ExifContent *c)
	Fix the IFD to bring it into specification.
void	exif_content_foreach_entry (ExifContent *content, ExifContentForeachEntryFunc func, void *user_data)
	Executes function on each EXIF tag in this IFD in turn.
ExifIfd	exif_content_get_ifd (ExifContent *c)
	Return the IFD number in which the given ExifContent is found.
void	exif_content_dump (ExifContent *content, unsigned int indent)
	Dump contents of the IFD to stdout.
void	exif_content_log (ExifContent *content, ExifLog *log)
	Set the log message object for this IFD.

Detailed Description

Handling EXIF IFDs.

Macro Definition Documentation

exif_content_get_value

#define exif_content_get_value	(		c,
			t,
			v,
			m
	)

Value:

        (exif_content_get_entry (c,t) ?                                 \
         exif_entry_get_value (exif_content_get_entry (c,t),v,m) : NULL)

Return a textual representation of the EXIF data for a tag.

Parameters

[in]	c	ExifContent* for an IFD
[in]	t	ExifTag to return
[out]	v	char* buffer in which to store value
[in]	m	unsigned int length of the buffer v

Returns

the v pointer, or NULL on error

Function Documentation

exif_content_add_entry()

void exif_content_add_entry	(	ExifContent *	c,
		ExifEntry *	entry
	)

Add an EXIF tag to an IFD.

If this tag already exists in the IFD, this function does nothing.

Precondition

The "tag" member of the entry must be set on entry.

Parameters

[out]	c	IFD
[in]	entry	EXIF entry to add

References _ExifEntry::parent, and _ExifEntry::tag.

exif_content_dump()

void exif_content_dump	(	ExifContent *	content,
		unsigned int	indent
	)

Dump contents of the IFD to stdout.

This is intended for diagnostic purposes only.

Parameters

[in]	content	IFD data
[in]	indent	how many levels deep to indent the data

exif_content_fix()

void exif_content_fix

(

ExifContent *

c

)

Fix the IFD to bring it into specification.

Call exif_entry_fix on each entry in this IFD to fix existing entries, create any new entries that are mandatory in this IFD but do not yet exist, and remove any entries that are not allowed in this IFD.

Parameters

[in,out]

c

EXIF content for an IFD

References EXIF_SUPPORT_LEVEL_MANDATORY, and _ExifContent::parent.

exif_content_foreach_entry()

void exif_content_foreach_entry	(	ExifContent *	content,
		ExifContentForeachEntryFunc	func,
		void *	user_data
	)

Executes function on each EXIF tag in this IFD in turn.

The tags will not necessarily be visited in numerical order.

Parameters

[in,out]	content	IFD over which to iterate
[in]	func	function to call for each entry
[in]	user_data	data to pass into func on each call

exif_content_free()

void exif_content_free

(

ExifContent *

content

)

Actually free the ExifContent.

Deprecated:

Should not be called directly. Use exif_content_ref and exif_content_unref instead.

Parameters

[in]

content

ExifContent

exif_content_get_entry()

ExifEntry * exif_content_get_entry	(	ExifContent *	content,
		ExifTag	tag
	)

Return the ExifEntry in this IFD corresponding to the given tag.

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

Parameters

[in]	content	EXIF content for an IFD
[in]	tag	EXIF tag to return

Returns

ExifEntry of the tag, or NULL on error

References _ExifEntry::tag.

exif_content_get_ifd()

ExifIfd exif_content_get_ifd

(

ExifContent *

c

)

Return the IFD number in which the given ExifContent is found.

Parameters

[in]

c

an ExifContent*

Returns

IFD number, or EXIF_IFD_COUNT on error

References _ExifContent::parent.

exif_content_log()

void exif_content_log	(	ExifContent *	content,
		ExifLog *	log
	)

Set the log message object for this IFD.

Parameters

[in]	content	IFD
[in]	log	ExifLog*

exif_content_new()

ExifContent * exif_content_new

(

void

)

Reserve memory for and initialize a new ExifContent.

Returns

new allocated ExifContent, or NULL on error

See also

exif_content_new_mem, exif_content_unref

exif_content_new_mem()

ExifContent * exif_content_new_mem

(

ExifMem *

mem

)

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

Returns

new allocated ExifContent, or NULL on error

See also

exif_content_new, exif_content_unref

exif_content_ref()

void exif_content_ref

(

ExifContent *

content

)

Increase reference counter for ExifContent.

Parameters

[in]

content

ExifContent

See also

exif_content_unref

exif_content_remove_entry()

void exif_content_remove_entry	(	ExifContent *	c,
		ExifEntry *	e
	)

Remove an EXIF tag from an IFD.

If this tag does not exist in the IFD, this function does nothing.

Parameters

[out]	c	IFD
[in]	e	EXIF entry to remove

References _ExifEntry::parent.

exif_content_unref()

void exif_content_unref

(

ExifContent *

content

)

Decrease reference counter for ExifContent.

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

Parameters

[in]

content

ExifContent