Functions related to EXIF metadata: gexiv2 Reference Manual

Functions related to EXIF metadata

Functions related to EXIF metadata — Functionality specific to the EXIF familiy of metadata information

Functions

gboolean	gexiv2_metadata_is_exif_tag ()
gboolean	gexiv2_metadata_get_supports_exif ()
gboolean	gexiv2_metadata_has_exif ()
gchar **	gexiv2_metadata_get_exif_tags ()
void	gexiv2_metadata_clear_exif ()
gboolean	gexiv2_metadata_try_get_exif_tag_rational ()
gboolean	gexiv2_metadata_try_set_exif_tag_rational ()
gboolean	gexiv2_metadata_get_exif_thumbnail ()
GBytes *	gexiv2_metadata_get_exif_data ()
gboolean	gexiv2_metadata_set_exif_thumbnail_from_file ()
void	gexiv2_metadata_try_set_exif_thumbnail_from_buffer ()
void	gexiv2_metadata_try_erase_exif_thumbnail ()
gboolean	gexiv2_metadata_get_exif_tag_rational ()
gboolean	gexiv2_metadata_set_exif_tag_rational ()
void	gexiv2_metadata_set_exif_thumbnail_from_buffer ()
void	gexiv2_metadata_erase_exif_thumbnail ()

Includes

#include <gexiv2/gexiv2.h>

Description

While being part of GExiv2Metadata, these functions are dealing with specific aspects of EXIF

Functions

gexiv2_metadata_is_exif_tag ()

gboolean
gexiv2_metadata_is_exif_tag (const gchar *tag);

The Exiv2 Tag Reference can be found at http://exiv2.org/metadata.html

Parameters

tag

An Exiv2 tag

Returns

TRUE if the Exiv2 tag is for the EXIF domain.

gexiv2_metadata_get_supports_exif ()

gboolean
gexiv2_metadata_get_supports_exif (GExiv2Metadata *self);

Query self whether it supports writing EXIF metadata.

Parameters

self

An instance of GExiv2Metadata

Returns

TRUE if the loaded image type supports writing EXIF metadata.

gexiv2_metadata_has_exif ()

gboolean
gexiv2_metadata_has_exif (GExiv2Metadata *self);

Parameters

self

An instance of GExiv2Metadata

Returns

TRUE if EXIF metadata is present in the loaded image

gexiv2_metadata_get_exif_tags ()

gchar **
gexiv2_metadata_get_exif_tags (GExiv2Metadata *self);

Query self for a list of available EXIF tags

Parameters

self

An instance of GExiv2Metadata

Returns

A unique list of the available EXIF tags in the loaded image.

[transfer full][array zero-terminated=1]

gexiv2_metadata_clear_exif ()

void
gexiv2_metadata_clear_exif (GExiv2Metadata *self);

Clears all EXIF metadata from the loaded image.

Parameters

self

An instance of GExiv2Metadata

gexiv2_metadata_try_get_exif_tag_rational ()

gboolean
gexiv2_metadata_try_get_exif_tag_rational
                               (GExiv2Metadata *self,
                                const gchar *tag,
                                gint *nom,
                                gint *den,
                                GError **error);

Fetch EXIF tag represented by a fraction. nom will contain the numerator, den the denominator of the fraction on successful return.

Parameters

self	An instance of GExiv2Metadata
tag	The tag you want the rational value for.	[in]
nom	The numerator.	[out]
den	The denominator.	[out]
error	A return location for a GError or `NULL`.	[allow-none]

Returns

Boolean success value.

[skip]

Since: 0.12.2

gexiv2_metadata_try_set_exif_tag_rational ()

gboolean
gexiv2_metadata_try_set_exif_tag_rational
                               (GExiv2Metadata *self,
                                const gchar *tag,
                                gint nom,
                                gint den,
                                GError **error);

Set EXIF tag represented by a fraction, with nom being the numerator, den the denominator of the fraction.

Parameters

self	An instance of GExiv2Metadata
tag	The Exiv2 tag.	[in]
nom	Rational numerator
den	Rational denominator
error	A return location for a GError or `NULL`.	[allow-none]

Returns

Boolean success value.

[skip]

Since: 0.12.2

gexiv2_metadata_get_exif_thumbnail ()

gboolean
gexiv2_metadata_get_exif_thumbnail (GExiv2Metadata *self,
                                    guint8 **buffer,
                                    gint *size);

Get the thumbnail stored in the EXIF data of self

Parameters

self	An instance of GExiv2Metadata
buffer	Where to store the thumbnail data.	[out][array length=size][transfer full]
size	Size of the thumbnail's buffer.	[skip]

Returns

Boolean success value.

[skip]

gexiv2_metadata_get_exif_data ()

GBytes *
gexiv2_metadata_get_exif_data (GExiv2Metadata *self,
                               GExiv2ByteOrder byte_order,
                               GError **error);

Parameters

self	An instance of GExiv2Metadata
byte_order	Whether to export the data in little or big endian format
error	A return location for a GError or `NULL`.	[allow-none]

Returns

The content of the EXIF data or NULL on error.

[transfer full][allow-none]

Since: 0.12.2

gexiv2_metadata_set_exif_thumbnail_from_file ()

gboolean
gexiv2_metadata_set_exif_thumbnail_from_file
                               (GExiv2Metadata *self,
                                const gchar *path,
                                GError **error);

Sets or replaces the EXIF thumbnail with the image in the file

Parameters

self	An instance of GExiv2Metadata
path	Path of image file.	[in]
error	A return location for a GError or `NULL`.	[allow-none]

Returns

Boolean success value

gexiv2_metadata_try_set_exif_thumbnail_from_buffer ()

void
gexiv2_metadata_try_set_exif_thumbnail_from_buffer
                               (GExiv2Metadata *self,
                                const guint8 *buffer,
                                gint size,
                                GError **error);

Parameters

self	An instance of GExiv2Metadata
buffer	A buffer containing thumbnail data.	[array length=size]
size	Size of the thumbnail's buffer.	[skip]
error	A return location for a GError or `NULL`.	[allow-none]

Since: 0.14.0

gexiv2_metadata_try_erase_exif_thumbnail ()

void
gexiv2_metadata_try_erase_exif_thumbnail
                               (GExiv2Metadata *self,
                                GError **error);

Removes the EXIF thumbnail from the loaded image.

Parameters

self	An instance of GExiv2Metadata
error	A return location for a GError or `NULL`.	[allow-none]

Since: 0.14.0

gexiv2_metadata_get_exif_tag_rational ()

gboolean
gexiv2_metadata_get_exif_tag_rational (GExiv2Metadata *self,
                                       const gchar *tag,
                                       gint *nom,
                                       gint *den);

gexiv2_metadata_get_exif_tag_rational has been deprecated since version 0.12.2 and should not be used in newly-written code.

Use gexiv2_metadata_try_get_exif_tag_rational() instead.

Fetch EXIF tag represented by a fraction. nom will contain the numerator, den the denominator of the fraction on successful return.

Parameters

self	An instance of GExiv2Metadata
tag	The tag you want the rational value for.	[in]
nom	The numerator.	[out]
den	The denominator.	[out]

Returns

Boolean success value.

[skip]

gexiv2_metadata_set_exif_tag_rational ()

gboolean
gexiv2_metadata_set_exif_tag_rational (GExiv2Metadata *self,
                                       const gchar *tag,
                                       gint nom,
                                       gint den);

gexiv2_metadata_set_exif_tag_rational has been deprecated since version 0.12.2 and should not be used in newly-written code.

Use gexiv2_metadata_try_set_exif_tag_rational() instead.

Set EXIF tag represented by a fraction, with nom being the numerator, den the denominator of the fraction.

Parameters

self	An instance of GExiv2Metadata
tag	The Exiv2 tag.	[in]
nom	Rational numerator
den	Rational denominator

Returns

Boolean success value.

[skip]

gexiv2_metadata_set_exif_thumbnail_from_buffer ()

void
gexiv2_metadata_set_exif_thumbnail_from_buffer
                               (GExiv2Metadata *self,
                                const guint8 *buffer,
                                gint size);

gexiv2_metadata_set_exif_thumbnail_from_buffer has been deprecated since version 0.14.0 and should not be used in newly-written code.

Use gexiv2_metadata_try_set_exif_thumbnail_from_buffer() instead.

Parameters

self	An instance of GExiv2Metadata
buffer	A buffer containing thumbnail data.	[array length=size]
size	Size of the thumbnail's buffer.	[skip]

gexiv2_metadata_erase_exif_thumbnail ()

void
gexiv2_metadata_erase_exif_thumbnail (GExiv2Metadata *self);

gexiv2_metadata_erase_exif_thumbnail has been deprecated since version 0.14.0 and should not be used in newly-written code.

Use gexiv2_metadata_try_erase_exif_thumbnail() instead.

Removes the EXIF thumbnail from the loaded image.

Parameters

self

An instance of GExiv2Metadata