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GStreamer 0.10 Core Reference Manual | ![]() |
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#include <gst/gst.h> GstStructure; gboolean (*GstStructureForeachFunc) (GQuark field_id, const GValue *value, gpointer user_data); gboolean (*GstStructureMapFunc) (GQuark field_id, GValue *value, gpointer user_data); GstStructure* gst_structure_empty_new (const gchar *name); GstStructure* gst_structure_id_empty_new (GQuark quark); GstStructure* gst_structure_new (const gchar *name, const gchar *firstfield, ...); GstStructure* gst_structure_new_valist (const gchar *name, const gchar *firstfield, va_list varargs); GstStructure* gst_structure_id_new (GQuark name_quark, GQuark field_quark, ...); GstStructure* gst_structure_copy (const GstStructure *structure); void gst_structure_free (GstStructure *structure); const gchar* gst_structure_get_name (const GstStructure *structure); gboolean gst_structure_has_name (const GstStructure *structure, const gchar *name); void gst_structure_set_name (GstStructure *structure, const gchar *name); GQuark gst_structure_get_name_id (const GstStructure *structure); gboolean gst_structure_id_get (GstStructure *structure, GQuark first_field_id, ...); gboolean gst_structure_id_get_valist (GstStructure *structure, GQuark first_field_id, va_list args); const GValue* gst_structure_id_get_value (const GstStructure *structure, GQuark field); void gst_structure_id_set_value (GstStructure *structure, GQuark field, const GValue *value); gboolean gst_structure_get (GstStructure *structure, const char *first_fieldname, ...); gboolean gst_structure_get_valist (GstStructure *structure, const char *first_fieldname, va_list args); const GValue* gst_structure_get_value (const GstStructure *structure, const gchar *fieldname); void gst_structure_set_value (GstStructure *structure, const gchar *fieldname, const GValue *value); void gst_structure_set (GstStructure *structure, const gchar *fieldname, ...); void gst_structure_set_valist (GstStructure *structure, const gchar *fieldname, va_list varargs); void gst_structure_id_set (GstStructure *structure, GQuark fieldname, ...); void gst_structure_id_set_valist (GstStructure *structure, GQuark fieldname, va_list varargs); void gst_structure_remove_field (GstStructure *structure, const gchar *fieldname); void gst_structure_remove_fields (GstStructure *structure, const gchar *fieldname, ...); void gst_structure_remove_fields_valist (GstStructure *structure, const gchar *fieldname, va_list varargs); void gst_structure_remove_all_fields (GstStructure *structure); GType gst_structure_get_field_type (const GstStructure *structure, const gchar *fieldname); gboolean gst_structure_foreach (const GstStructure *structure, GstStructureForeachFunc func, gpointer user_data); gint gst_structure_n_fields (const GstStructure *structure); gboolean gst_structure_has_field (const GstStructure *structure, const gchar *fieldname); gboolean gst_structure_has_field_typed (const GstStructure *structure, const gchar *fieldname, GType type); gboolean gst_structure_get_boolean (const GstStructure *structure, const gchar *fieldname, gboolean *value); gboolean gst_structure_get_int (const GstStructure *structure, const gchar *fieldname, gint *value); gboolean gst_structure_get_uint (const GstStructure *structure, const gchar *fieldname, guint *value); gboolean gst_structure_get_fourcc (const GstStructure *structure, const gchar *fieldname, guint32 *value); gboolean gst_structure_get_double (const GstStructure *structure, const gchar *fieldname, gdouble *value); const gchar* gst_structure_get_string (const GstStructure *structure, const gchar *fieldname); gboolean gst_structure_get_date (const GstStructure *structure, const gchar *fieldname, GDate **value); gboolean gst_structure_get_clock_time (const GstStructure *structure, const gchar *fieldname, GstClockTime *value); gboolean gst_structure_get_enum (const GstStructure *structure, const gchar *fieldname, GType enumtype, gint *value); gboolean gst_structure_get_fraction (const GstStructure *structure, const gchar *fieldname, gint *value_numerator, gint *value_denominator); gboolean gst_structure_map_in_place (GstStructure *structure, GstStructureMapFunc func, gpointer user_data); const gchar* gst_structure_nth_field_name (const GstStructure *structure, guint index); void gst_structure_set_parent_refcount (GstStructure *structure, gint *refcount); gchar* gst_structure_to_string (const GstStructure *structure); GstStructure* gst_structure_from_string (const gchar *string, gchar **end); gboolean gst_structure_fixate_field_nearest_int (GstStructure *structure, const char *field_name, int target); gboolean gst_structure_fixate_field_nearest_double (GstStructure *structure, const char *field_name, double target); gboolean gst_structure_fixate_field_nearest_fraction (GstStructure *structure, const char *field_name, const gint target_numerator, const gint target_denominator); gboolean gst_structure_fixate_field_boolean (GstStructure *structure, const char *field_name, gboolean target);
A GstStructure is a collection of key/value pairs. The keys are expressed as GQuarks and the values can be of any GType.
In addition to the key/value pairs, a GstStructure also has a name. The name starts with a letter and can be folled by letters, numbers and any of "/-_.:".
GstStructure is used by various GStreamer subsystems to store information
in a flexible and extensible way. A GstStructure does not have a refcount
because it usually is part of a higher level object such as GstCaps. It
provides a means to enforce mutability using the refcount of the parent
with the gst_structure_set_parent_refcount()
method.
A GstStructure can be created with gst_structure_empty_new()
or
gst_structure_new()
, which both take a name and an optional set of
key/value pairs along with the types of the values.
Field values can be changed with gst_structure_set_value()
or
gst_structure_set()
.
Field values can be retrieved with gst_structure_get_value()
or the more
convenient gst_structure_get_*() functions.
Fields can be removed with gst_structure_remove_field()
or
gst_structure_remove_fields()
.
Strings in structures must be ASCII or UTF-8 encoded. Other encodings are not allowed. Strings must not be empty either, but may be NULL.
Last reviewed on 2009-06-08 (0.10.23)
typedef struct { GType type; } GstStructure;
The GstStructure object. Most fields are private.
GType type ; |
the GType of a structure |
gboolean (*GstStructureForeachFunc) (GQuark field_id, const GValue *value, gpointer user_data);
A function that will be called in gst_structure_foreach()
. The function may
not modify value
.
field_id : |
the GQuark of the field name |
value : |
the GValue of the field |
user_data : |
user data |
Returns : | TRUE if the foreach operation should continue, FALSE if the foreach operation should stop with FALSE. |
gboolean (*GstStructureMapFunc) (GQuark field_id, GValue *value, gpointer user_data);
A function that will be called in gst_structure_map_in_place()
. The function
may modify value
.
field_id : |
the GQuark of the field name |
value : |
the GValue of the field |
user_data : |
user data |
Returns : | TRUE if the map operation should continue, FALSE if the map operation should stop with FALSE. |
GstStructure* gst_structure_empty_new (const gchar *name);
Creates a new, empty GstStructure with the given name
.
See gst_structure_set_name()
for constraints on the name
parameter.
name : |
name of new structure |
Returns : | a new, empty GstStructure |
GstStructure* gst_structure_id_empty_new (GQuark quark);
Creates a new, empty GstStructure with the given name as a GQuark.
quark : |
name of new structure |
Returns : | a new, empty GstStructure |
GstStructure* gst_structure_new (const gchar *name, const gchar *firstfield, ...);
Creates a new GstStructure with the given name. Parses the list of variable arguments and sets fields to the values listed. Variable arguments should be passed as field name, field type, and value. Last variable argument should be NULL.
name : |
name of new structure |
firstfield : |
name of first field to set |
... : |
additional arguments |
Returns : | a new GstStructure |
GstStructure* gst_structure_new_valist (const gchar *name, const gchar *firstfield, va_list varargs);
Creates a new GstStructure with the given name
. Structure fields
are set according to the varargs in a manner similar to
gst_structure_new()
.
See gst_structure_set_name()
for constraints on the name
parameter.
name : |
name of new structure |
firstfield : |
name of first field to set |
varargs : |
variable argument list |
Returns : | a new GstStructure |
GstStructure* gst_structure_id_new (GQuark name_quark, GQuark field_quark, ...);
Creates a new GstStructure with the given name as a GQuark, followed by
fieldname quark, GType, argument(s) "triplets" in the same format as
gst_structure_id_set()
. Basically a convenience wrapper around
gst_structure_id_empty_new()
and gst_structure_id_set()
.
The last variable argument must be NULL (or 0).
name_quark : |
name of new structure |
field_quark : |
the GQuark for the name of the field to set |
... : |
variable arguments |
Returns : | a new GstStructure |
Since 0.10.24
GstStructure* gst_structure_copy (const GstStructure *structure);
Duplicates a GstStructure and all its fields and values.
structure : |
a GstStructure to duplicate |
Returns : | a new GstStructure. |
void gst_structure_free (GstStructure *structure);
Frees a GstStructure and all its fields and values. The structure must not have a parent when this function is called.
structure : |
the GstStructure to free |
const gchar* gst_structure_get_name (const GstStructure *structure);
Get the name of structure
as a string.
structure : |
a GstStructure |
Returns : | the name of the structure. |
gboolean gst_structure_has_name (const GstStructure *structure, const gchar *name);
Checks if the structure has the given name
structure : |
a GstStructure |
name : |
structure name to check for |
Returns : | TRUE if name matches the name of the structure.
|
void gst_structure_set_name (GstStructure *structure, const gchar *name);
Sets the name of the structure to the given name
. The string
provided is copied before being used. It must not be empty, start with a
letter and can be followed by letters, numbers and any of "/-_.:".
structure : |
a GstStructure |
name : |
the new name of the structure |
GQuark gst_structure_get_name_id (const GstStructure *structure);
Get the name of structure
as a GQuark.
structure : |
a GstStructure |
Returns : | the quark representing the name of the structure. |
gboolean gst_structure_id_get (GstStructure *structure, GQuark first_field_id, ...);
Parses the variable arguments and reads fields from structure
accordingly.
Variable arguments should be in the form field id quark, field type
(as a GType), pointer(s) to a variable(s) to hold the return value(s).
The last variable argument should be NULL (technically it should be a
0 quark, but we require NULL so compilers that support it can check for
the NULL terminator and warn if it's not there).
This function is just like gst_structure_get()
only that it is slightly
more efficient since it saves the string-to-quark lookup in the global
quark hashtable.
For refcounted (mini)objects you will acquire your own reference which
you must release with a suitable _unref()
when no longer needed. For
strings and boxed types you will acquire a copy which you will need to
release with either g_free()
or the suiteable function for the boxed type.
structure : |
a GstStructure |
first_field_id : |
the quark of the first field to read |
... : |
variable arguments |
Returns : | FALSE if there was a problem reading any of the fields (e.g. because the field requested did not exist, or was of a type other than the type specified), otherwise TRUE. |
Since 0.10.24
gboolean gst_structure_id_get_valist (GstStructure *structure, GQuark first_field_id, va_list args);
Parses the variable arguments and reads fields from structure
accordingly.
valist-variant of gst_structure_id_get()
. Look at the documentation of
gst_structure_id_get()
for more details.
structure : |
a GstStructure |
first_field_id : |
the quark of the first field to read |
args : |
variable arguments |
Returns : | TRUE, or FALSE if there was a problem reading any of the fields |
Since 0.10.24
const GValue* gst_structure_id_get_value (const GstStructure *structure, GQuark field);
Get the value of the field with GQuark field
.
structure : |
a GstStructure |
field : |
the GQuark of the field to get |
Returns : | the GValue corresponding to the field with the given name identifier. |
void gst_structure_id_set_value (GstStructure *structure, GQuark field, const GValue *value);
Sets the field with the given GQuark field
to value
. If the field
does not exist, it is created. If the field exists, the previous
value is replaced and freed.
structure : |
a GstStructure |
field : |
a GQuark representing a field |
value : |
the new value of the field |
gboolean gst_structure_get (GstStructure *structure, const char *first_fieldname, ...);
Parses the variable arguments and reads fields from structure
accordingly.
Variable arguments should be in the form field name, field type
(as a GType), pointer(s) to a variable(s) to hold the return value(s).
The last variable argument should be NULL.
For refcounted (mini)objects you will acquire your own reference which
you must release with a suitable _unref()
when no longer needed. For
strings and boxed types you will acquire a copy which you will need to
release with either g_free()
or the suiteable function for the boxed type.
structure : |
a GstStructure |
first_fieldname : |
the name of the first field to read |
... : |
variable arguments |
Returns : | FALSE if there was a problem reading any of the fields (e.g. because the field requested did not exist, or was of a type other than the type specified), otherwise TRUE. |
Since 0.10.24
gboolean gst_structure_get_valist (GstStructure *structure, const char *first_fieldname, va_list args);
Parses the variable arguments and reads fields from structure
accordingly.
valist-variant of gst_structure_get()
. Look at the documentation of
gst_structure_get()
for more details.
structure : |
a GstStructure |
first_fieldname : |
the name of the first field to read |
args : |
variable arguments |
Returns : | TRUE, or FALSE if there was a problem reading any of the fields |
Since 0.10.24
const GValue* gst_structure_get_value (const GstStructure *structure, const gchar *fieldname);
Get the value of the field with name fieldname
.
structure : |
a GstStructure |
fieldname : |
the name of the field to get |
Returns : | the GValue corresponding to the field with the given name. |
void gst_structure_set_value (GstStructure *structure, const gchar *fieldname, const GValue *value);
Sets the field with the given name field
to value
. If the field
does not exist, it is created. If the field exists, the previous
value is replaced and freed.
structure : |
a GstStructure |
fieldname : |
the name of the field to set |
value : |
the new value of the field |
void gst_structure_set (GstStructure *structure, const gchar *fieldname, ...);
Parses the variable arguments and sets fields accordingly. Variable arguments should be in the form field name, field type (as a GType), value(s). The last variable argument should be NULL.
structure : |
a GstStructure |
fieldname : |
the name of the field to set |
... : |
variable arguments |
void gst_structure_set_valist (GstStructure *structure, const gchar *fieldname, va_list varargs);
va_list form of gst_structure_set()
.
structure : |
a GstStructure |
fieldname : |
the name of the field to set |
varargs : |
variable arguments |
void gst_structure_id_set (GstStructure *structure, GQuark fieldname, ...);
Identical to gst_structure_set, except that field names are passed using the GQuark for the field name. This allows more efficient setting of the structure if the caller already knows the associated quark values. The last variable argument must be NULL.
structure : |
a GstStructure |
fieldname : |
the GQuark for the name of the field to set |
... : |
variable arguments |
Since 0.10.10
void gst_structure_id_set_valist (GstStructure *structure, GQuark fieldname, va_list varargs);
va_list form of gst_structure_id_set()
.
structure : |
a GstStructure |
fieldname : |
the name of the field to set |
varargs : |
variable arguments |
Since 0.10.10
void gst_structure_remove_field (GstStructure *structure, const gchar *fieldname);
Removes the field with the given name. If the field with the given name does not exist, the structure is unchanged.
structure : |
a GstStructure |
fieldname : |
the name of the field to remove |
void gst_structure_remove_fields (GstStructure *structure, const gchar *fieldname, ...);
Removes the fields with the given names. If a field does not exist, the argument is ignored.
structure : |
a GstStructure |
fieldname : |
the name of the field to remove |
... : |
NULL-terminated list of more fieldnames to remove |
void gst_structure_remove_fields_valist (GstStructure *structure, const gchar *fieldname, va_list varargs);
va_list form of gst_structure_remove_fields()
.
structure : |
a GstStructure |
fieldname : |
the name of the field to remove |
varargs : |
NULL-terminated list of more fieldnames to remove |
void gst_structure_remove_all_fields (GstStructure *structure);
Removes all fields in a GstStructure.
structure : |
a GstStructure |
GType gst_structure_get_field_type (const GstStructure *structure, const gchar *fieldname);
Finds the field with the given name, and returns the type of the value it contains. If the field is not found, G_TYPE_INVALID is returned.
structure : |
a GstStructure |
fieldname : |
the name of the field |
Returns : | the GValue of the field |
gboolean gst_structure_foreach (const GstStructure *structure, GstStructureForeachFunc func, gpointer user_data);
Calls the provided function once for each field in the GstStructure. The
function must not modify the fields. Also see gst_structure_map_in_place()
.
structure : |
a GstStructure |
func : |
a function to call for each field |
user_data : |
private data |
Returns : | TRUE if the supplied function returns TRUE For each of the fields, FALSE otherwise. |
gint gst_structure_n_fields (const GstStructure *structure);
Get the number of fields in the structure.
structure : |
a GstStructure |
Returns : | the number of fields in the structure |
gboolean gst_structure_has_field (const GstStructure *structure, const gchar *fieldname);
Check if structure
contains a field named fieldname
.
structure : |
a GstStructure |
fieldname : |
the name of a field |
Returns : | TRUE if the structure contains a field with the given name |
gboolean gst_structure_has_field_typed (const GstStructure *structure, const gchar *fieldname, GType type);
Check if structure
contains a field named fieldname
and with GType type
.
structure : |
a GstStructure |
fieldname : |
the name of a field |
type : |
the type of a value |
Returns : | TRUE if the structure contains a field with the given name and type |
gboolean gst_structure_get_boolean (const GstStructure *structure, const gchar *fieldname, gboolean *value);
Sets the boolean pointed to by value
corresponding to the value of the
given field. Caller is responsible for making sure the field exists
and has the correct type.
structure : |
a GstStructure |
fieldname : |
the name of a field |
value : |
a pointer to a gboolean to set |
Returns : | TRUE if the value could be set correctly. If there was no field
with fieldname or the existing field did not contain a boolean, this
function returns FALSE.
|
gboolean gst_structure_get_int (const GstStructure *structure, const gchar *fieldname, gint *value);
Sets the int pointed to by value
corresponding to the value of the
given field. Caller is responsible for making sure the field exists
and has the correct type.
structure : |
a GstStructure |
fieldname : |
the name of a field |
value : |
a pointer to an int to set |
Returns : | TRUE if the value could be set correctly. If there was no field
with fieldname or the existing field did not contain an int, this function
returns FALSE .
|
gboolean gst_structure_get_uint (const GstStructure *structure, const gchar *fieldname, guint *value);
Sets the uint pointed to by value
corresponding to the value of the
given field. Caller is responsible for making sure the field exists
and has the correct type.
structure : |
a GstStructure |
fieldname : |
the name of a field |
value : |
a pointer to a uint to set |
Returns : | TRUE if the value could be set correctly. If there was no field
with fieldname or the existing field did not contain a uint, this function
returns FALSE .
|
Since 0.10.15
gboolean gst_structure_get_fourcc (const GstStructure *structure, const gchar *fieldname, guint32 *value);
Sets the GstFourcc pointed to by value
corresponding to the value of the
given field. Caller is responsible for making sure the field exists
and has the correct type.
structure : |
a GstStructure |
fieldname : |
the name of a field |
value : |
a pointer to a GstFourcc to set |
Returns : | TRUE if the value could be set correctly. If there was no field
with fieldname or the existing field did not contain a fourcc, this function
returns FALSE.
|
gboolean gst_structure_get_double (const GstStructure *structure, const gchar *fieldname, gdouble *value);
Sets the double pointed to by value
corresponding to the value of the
given field. Caller is responsible for making sure the field exists
and has the correct type.
structure : |
a GstStructure |
fieldname : |
the name of a field |
value : |
a pointer to a GstFourcc to set |
Returns : | TRUE if the value could be set correctly. If there was no field
with fieldname or the existing field did not contain a double, this
function returns FALSE.
|
const gchar* gst_structure_get_string (const GstStructure *structure, const gchar *fieldname);
Finds the field corresponding to fieldname
, and returns the string
contained in the field's value. Caller is responsible for making
sure the field exists and has the correct type.
The string should not be modified, and remains valid until the next call to a gst_structure_*() function with the given structure.
structure : |
a GstStructure |
fieldname : |
the name of a field |
Returns : | a pointer to the string or NULL when the field did not exist or did not contain a string. |
gboolean gst_structure_get_date (const GstStructure *structure, const gchar *fieldname, GDate **value);
Sets the date pointed to by value
corresponding to the date of the
given field. Caller is responsible for making sure the field exists
and has the correct type.
On success value
will point to a newly-allocated copy of the date which
should be freed with g_date_free()
when no longer needed (note: this is
inconsistent with e.g. gst_structure_get_string()
which doesn't return a
copy of the string).
structure : |
a GstStructure |
fieldname : |
the name of a field |
value : |
a pointer to a GDate to set |
Returns : | TRUE if the value could be set correctly. If there was no field
with fieldname or the existing field did not contain a data, this function
returns FALSE.
|
gboolean gst_structure_get_clock_time (const GstStructure *structure, const gchar *fieldname, GstClockTime *value);
Sets the clock time pointed to by value
corresponding to the clock time
of the given field. Caller is responsible for making sure the field exists
and has the correct type.
structure : |
a GstStructure |
fieldname : |
the name of a field |
value : |
a pointer to a GstClockTime to set |
Returns : | TRUE if the value could be set correctly. If there was no field
with fieldname or the existing field did not contain a GstClockTime, this
function returns FALSE.
|
gboolean gst_structure_get_enum (const GstStructure *structure, const gchar *fieldname, GType enumtype, gint *value);
Sets the int pointed to by value
corresponding to the value of the
given field. Caller is responsible for making sure the field exists,
has the correct type and that the enumtype is correct.
structure : |
a GstStructure |
fieldname : |
the name of a field |
enumtype : |
the enum type of a field |
value : |
a pointer to an int to set |
Returns : | TRUE if the value could be set correctly. If there was no field
with fieldname or the existing field did not contain an enum of the given
type, this function returns FALSE.
|
gboolean gst_structure_get_fraction (const GstStructure *structure, const gchar *fieldname, gint *value_numerator, gint *value_denominator);
Sets the integers pointed to by value_numerator
and value_denominator
corresponding to the value of the given field. Caller is responsible
for making sure the field exists and has the correct type.
structure : |
a GstStructure |
fieldname : |
the name of a field |
value_numerator : |
a pointer to an int to set |
value_denominator : |
a pointer to an int to set |
Returns : | TRUE if the values could be set correctly. If there was no field
with fieldname or the existing field did not contain a GstFraction, this
function returns FALSE.
|
gboolean gst_structure_map_in_place (GstStructure *structure, GstStructureMapFunc func, gpointer user_data);
Calls the provided function once for each field in the GstStructure. In
contrast to gst_structure_foreach()
, the function may modify but not delete the
fields. The structure must be mutable.
structure : |
a GstStructure |
func : |
a function to call for each field |
user_data : |
private data |
Returns : | TRUE if the supplied function returns TRUE For each of the fields, FALSE otherwise. |
const gchar* gst_structure_nth_field_name (const GstStructure *structure, guint index);
Get the name of the given field number, counting from 0 onwards.
structure : |
a GstStructure |
index : |
the index to get the name of |
Returns : | the name of the given field number |
void gst_structure_set_parent_refcount (GstStructure *structure, gint *refcount);
Sets the parent_refcount field of GstStructure. This field is used to determine whether a structure is mutable or not. This function should only be called by code implementing parent objects of GstStructure, as described in the MT Refcounting section of the design documents.
structure : |
a GstStructure |
refcount : |
a pointer to the parent's refcount |
gchar* gst_structure_to_string (const GstStructure *structure);
Converts structure
to a human-readable string representation.
For debugging purposes its easier to do something like this:
GST_LOG ("structure is %" GST_PTR_FORMAT, structure);
This prints the structure in human readble form.
structure : |
a GstStructure |
Returns : | a pointer to string allocated by g_malloc() . g_free() after
usage.
|
GstStructure* gst_structure_from_string (const gchar *string, gchar **end);
Creates a GstStructure from a string representation. If end is not NULL, a pointer to the place inside the given string where parsing ended will be returned.
string : |
a string representation of a GstStructure. |
end : |
pointer to store the end of the string in. |
Returns : | a new GstStructure or NULL when the string could not
be parsed. Free with gst_structure_free() after use.
|
gboolean gst_structure_fixate_field_nearest_int (GstStructure *structure, const char *field_name, int target);
Fixates a GstStructure by changing the given field to the nearest
integer to target
that is a subset of the existing field.
structure : |
a GstStructure |
field_name : |
a field in structure
|
target : |
the target value of the fixation |
Returns : | TRUE if the structure could be fixated |
gboolean gst_structure_fixate_field_nearest_double (GstStructure *structure, const char *field_name, double target);
Fixates a GstStructure by changing the given field to the nearest
double to target
that is a subset of the existing field.
structure : |
a GstStructure |
field_name : |
a field in structure
|
target : |
the target value of the fixation |
Returns : | TRUE if the structure could be fixated |
gboolean gst_structure_fixate_field_nearest_fraction (GstStructure *structure, const char *field_name, const gint target_numerator, const gint target_denominator);
Fixates a GstStructure by changing the given field to the nearest
fraction to target_numerator
/target_denominator
that is a subset
of the existing field.
structure : |
a GstStructure |
field_name : |
a field in structure
|
target_numerator : |
The numerator of the target value of the fixation |
target_denominator : |
The denominator of the target value of the fixation |
Returns : | TRUE if the structure could be fixated |
gboolean gst_structure_fixate_field_boolean (GstStructure *structure, const char *field_name, gboolean target);
Fixates a GstStructure by changing the given field_name
field to the given
target
boolean if that field is not fixed yet.
structure : |
a GstStructure |
field_name : |
a field in structure
|
target : |
the target value of the fixation |
Returns : | TRUE if the structure could be fixated |