gstreamer/gst/gststructure.c
Stefan Kost 7b347681d5 gst/gstelement.c: don't loop forever
Original commit message from CVS:
* gst/gstelement.c: (gst_element_dispose):
don't loop forever
* gst/gstiterator.c:
* gst/gststructure.c:
doc fixes
* libs/gst/controller/gstcontroller.c:
(gst_controlled_property_set_interpolation_mode):
* libs/gst/controller/gstcontroller.h:
* libs/gst/controller/gstinterpolation.c:
(interpolate_none_get_enum_value_array):
support controlling enums
2005-11-27 22:43:08 +00:00

2065 lines
52 KiB
C

/* GStreamer
* Copyright (C) 2003 David A. Schleef <ds@schleef.org>
*
* gststructure.c: lists of { GQuark, GValue } tuples
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library 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.
*/
/**
* SECTION:gststructure
* @short_description: Generic structure containing fields of names and values
* @see_also: #GstCaps, #GstMessage, #GstEvent, #GstQuery
*
* 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.
*
* #GstStructure is used by various GStreamer subsystems to store information in
* a flexible an 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().
*
* Last reviewed on 2005-11-09 (0.9.4)
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "gst_private.h"
#include <gst/gst.h>
#include <gobject/gvaluecollector.h>
typedef struct _GstStructureField GstStructureField;
struct _GstStructureField
{
GQuark name;
GValue value;
};
#define GST_STRUCTURE_FIELD(structure, index) \
&g_array_index((structure)->fields, GstStructureField, (index))
#define IS_MUTABLE(structure) \
(!(structure)->parent_refcount || \
g_atomic_int_get ((structure)->parent_refcount) == 1)
static void gst_structure_set_field (GstStructure * structure,
GstStructureField * field);
static GstStructureField *gst_structure_get_field (const GstStructure *
structure, const gchar * fieldname);
static GstStructureField *gst_structure_id_get_field (const GstStructure *
structure, GQuark field);
static void gst_structure_transform_to_string (const GValue * src_value,
GValue * dest_value);
static GstStructure *gst_structure_copy_conditional (const GstStructure *
structure);
static gboolean gst_structure_parse_value (gchar * str, gchar ** after,
GValue * value, GType default_type);
static gboolean gst_structure_parse_simple_string (gchar * s, gchar ** end);
GType
gst_structure_get_type (void)
{
static GType gst_structure_type = 0;
if (!gst_structure_type) {
gst_structure_type = g_boxed_type_register_static ("GstStructure",
(GBoxedCopyFunc) gst_structure_copy_conditional,
(GBoxedFreeFunc) gst_structure_free);
g_value_register_transform_func (gst_structure_type, G_TYPE_STRING,
gst_structure_transform_to_string);
}
return gst_structure_type;
}
static GstStructure *
gst_structure_id_empty_new_with_size (GQuark quark, guint prealloc)
{
GstStructure *structure;
structure = g_new0 (GstStructure, 1);
structure->type = gst_structure_get_type ();
structure->name = quark;
structure->fields =
g_array_sized_new (FALSE, TRUE, sizeof (GstStructureField), prealloc);
return structure;
}
/**
* gst_structure_id_empty_new:
* @quark: name of new structure
*
* Creates a new, empty #GstStructure with the given name as a GQuark.
*
* Returns: a new, empty #GstStructure
*/
GstStructure *
gst_structure_id_empty_new (GQuark quark)
{
g_return_val_if_fail (quark != 0, NULL);
return gst_structure_id_empty_new_with_size (quark, 0);
}
/**
* gst_structure_empty_new:
* @name: name of new structure
*
* Creates a new, empty #GstStructure with the given name.
*
* Returns: a new, empty #GstStructure
*/
GstStructure *
gst_structure_empty_new (const gchar * name)
{
g_return_val_if_fail (name != NULL, NULL);
return gst_structure_id_empty_new_with_size (g_quark_from_string (name), 0);
}
/**
* gst_structure_new:
* @name: name of new structure
* @firstfield: name of first field to set
* @...: additional arguments
*
* 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.
*
* Returns: a new #GstStructure
*/
GstStructure *
gst_structure_new (const gchar * name, const gchar * firstfield, ...)
{
GstStructure *structure;
va_list varargs;
g_return_val_if_fail (name != NULL, NULL);
va_start (varargs, firstfield);
structure = gst_structure_new_valist (name, firstfield, varargs);
va_end (varargs);
return structure;
}
/**
* gst_structure_new_valist:
* @name: name of new structure
* @firstfield: name of first field to set
* @varargs: variable argument list
*
* Creates a new #GstStructure with the given name. Structure fields
* are set according to the varargs in a manner similar to
* @gst_structure_new.
*
* Returns: a new #GstStructure
*/
GstStructure *
gst_structure_new_valist (const gchar * name,
const gchar * firstfield, va_list varargs)
{
GstStructure *structure;
g_return_val_if_fail (name != NULL, NULL);
structure = gst_structure_empty_new (name);
gst_structure_set_valist (structure, firstfield, varargs);
return structure;
}
/**
* gst_structure_set_parent_refcount:
* @structure: a #GstStructure
* @refcount: a pointer to the parent's 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.
*/
void
gst_structure_set_parent_refcount (GstStructure * structure, int *refcount)
{
g_return_if_fail (structure != NULL);
/* if we have a parent_refcount already, we can only clear
* if with a NULL refcount */
if (structure->parent_refcount)
g_return_if_fail (refcount == NULL);
else
g_return_if_fail (refcount != NULL);
structure->parent_refcount = refcount;
}
/**
* gst_structure_copy:
* @structure: a #GstStructure to duplicate
*
* Duplicates a #GstStructure and all its fields and values.
*
* Returns: a new #GstStructure.
*/
GstStructure *
gst_structure_copy (const GstStructure * structure)
{
GstStructure *new_structure;
GstStructureField *field;
guint i;
g_return_val_if_fail (structure != NULL, NULL);
new_structure =
gst_structure_id_empty_new_with_size (structure->name,
structure->fields->len);
for (i = 0; i < structure->fields->len; i++) {
GstStructureField new_field = { 0 };
field = GST_STRUCTURE_FIELD (structure, i);
new_field.name = field->name;
gst_value_init_and_copy (&new_field.value, &field->value);
g_array_append_val (new_structure->fields, new_field);
}
return new_structure;
}
/**
* gst_structure_free:
* @structure: the #GstStructure to free
*
* Frees a #GstStructure and all its fields and values. The structure must not
* have a parent when this function is called.
*/
void
gst_structure_free (GstStructure * structure)
{
GstStructureField *field;
guint i;
g_return_if_fail (structure != NULL);
g_return_if_fail (structure->parent_refcount == NULL);
for (i = 0; i < structure->fields->len; i++) {
field = GST_STRUCTURE_FIELD (structure, i);
if (G_IS_VALUE (&field->value)) {
g_value_unset (&field->value);
}
}
g_array_free (structure->fields, TRUE);
#ifdef USE_POISONING
memset (structure, 0xff, sizeof (GstStructure));
#endif
g_free (structure);
}
/**
* gst_structure_get_name:
* @structure: a #GstStructure
*
* Get the name of @structure as a string.
*
* Returns: the name of the structure.
*/
const gchar *
gst_structure_get_name (const GstStructure * structure)
{
g_return_val_if_fail (structure != NULL, NULL);
return g_quark_to_string (structure->name);
}
/**
* gst_structure_has_name:
* @structure: a #GstStructure
* @name: structure name to check for
*
* Checks if the structure has the given name
*
* Returns: TRUE if @name matches the name of the structure.
*/
gboolean
gst_structure_has_name (const GstStructure * structure, const gchar * name)
{
const gchar *structure_name;
g_return_val_if_fail (structure != NULL, FALSE);
g_return_val_if_fail (name != NULL, FALSE);
structure_name = g_quark_to_string (structure->name);
return (structure_name && strcmp (structure_name, name) == 0);
}
/**
* gst_structure_get_name_id:
* @structure: a #GstStructure
*
* Get the name of @structure as a GQuark.
*
* Returns: the quark representing the name of the structure.
*/
GQuark
gst_structure_get_name_id (const GstStructure * structure)
{
g_return_val_if_fail (structure != NULL, 0);
return structure->name;
}
/**
* gst_structure_set_name:
* @structure: a #GstStructure
* @name: the new name of the structure
*
* Sets the name of the structure to the given name. The string
* provided is copied before being used.
*/
void
gst_structure_set_name (GstStructure * structure, const gchar * name)
{
g_return_if_fail (structure != NULL);
g_return_if_fail (name != NULL);
g_return_if_fail (IS_MUTABLE (structure));
structure->name = g_quark_from_string (name);
}
/**
* gst_structure_id_set_value:
* @structure: a #GstStructure
* @field: a #GQuark representing a field
* @value: the new value of the field
*
* 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.
*/
void
gst_structure_id_set_value (GstStructure * structure,
GQuark field, const GValue * value)
{
GstStructureField gsfield = { 0, {0,} };
g_return_if_fail (structure != NULL);
g_return_if_fail (G_IS_VALUE (value));
g_return_if_fail (IS_MUTABLE (structure));
gsfield.name = field;
gst_value_init_and_copy (&gsfield.value, value);
gst_structure_set_field (structure, &gsfield);
}
/**
* gst_structure_set_value:
* @structure: a #GstStructure
* @fieldname: the name of the field to set
* @value: the new value of the field
*
* 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.
*/
void
gst_structure_set_value (GstStructure * structure,
const gchar * fieldname, const GValue * value)
{
g_return_if_fail (structure != NULL);
g_return_if_fail (fieldname != NULL);
g_return_if_fail (G_IS_VALUE (value));
g_return_if_fail (IS_MUTABLE (structure));
gst_structure_id_set_value (structure, g_quark_from_string (fieldname),
value);
}
/**
* gst_structure_set:
* @structure: a #GstStructure
* @fieldname: the name of the field to set
* @...: variable arguments
*
* 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.
*/
void
gst_structure_set (GstStructure * structure, const gchar * field, ...)
{
va_list varargs;
g_return_if_fail (structure != NULL);
va_start (varargs, field);
gst_structure_set_valist (structure, field, varargs);
va_end (varargs);
}
/**
* gst_structure_set_valist:
* @structure: a #GstStructure
* @fieldname: the name of the field to set
* @varargs: variable arguments
*
* va_list form of #gst_structure_set.
*/
void
gst_structure_set_valist (GstStructure * structure,
const gchar * fieldname, va_list varargs)
{
gchar *err = NULL;
GType type;
g_return_if_fail (structure != NULL);
g_return_if_fail (IS_MUTABLE (structure));
while (fieldname) {
GstStructureField field = { 0 };
field.name = g_quark_from_string (fieldname);
type = va_arg (varargs, GType);
#if GLIB_CHECK_VERSION(2,8,0)
if (type == G_TYPE_DATE) {
g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
type = GST_TYPE_DATE;
}
#endif
g_value_init (&field.value, type);
G_VALUE_COLLECT (&field.value, varargs, 0, &err);
if (err) {
g_critical ("%s", err);
return;
}
gst_structure_set_field (structure, &field);
fieldname = va_arg (varargs, gchar *);
}
}
/* If the structure currently contains a field with the same name, it is
* replaced with the provided field. Otherwise, the field is added to the
* structure. The field's value is not deeply copied.
*/
static void
gst_structure_set_field (GstStructure * structure, GstStructureField * field)
{
GstStructureField *f;
guint i;
for (i = 0; i < structure->fields->len; i++) {
f = GST_STRUCTURE_FIELD (structure, i);
if (f->name == field->name) {
g_value_unset (&f->value);
memcpy (f, field, sizeof (GstStructureField));
return;
}
}
g_array_append_val (structure->fields, *field);
}
/* If there is no field with the given ID, NULL is returned.
*/
static GstStructureField *
gst_structure_id_get_field (const GstStructure * structure, GQuark field_id)
{
GstStructureField *field;
guint i;
g_return_val_if_fail (structure != NULL, NULL);
for (i = 0; i < structure->fields->len; i++) {
field = GST_STRUCTURE_FIELD (structure, i);
if (field->name == field_id)
return field;
}
return NULL;
}
/* If there is no field with the given ID, NULL is returned.
*/
static GstStructureField *
gst_structure_get_field (const GstStructure * structure,
const gchar * fieldname)
{
g_return_val_if_fail (structure != NULL, NULL);
g_return_val_if_fail (fieldname != NULL, NULL);
return gst_structure_id_get_field (structure,
g_quark_from_string (fieldname));
}
/**
* gst_structure_get_value:
* @structure: a #GstStructure
* @fieldname: the name of the field to get
*
* Get the value of the field with name @fieldname.
*
* Returns: the #GValue corresponding to the field with the given name.
*/
const GValue *
gst_structure_get_value (const GstStructure * structure,
const gchar * fieldname)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, NULL);
g_return_val_if_fail (fieldname != NULL, NULL);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return NULL;
return &field->value;
}
/**
* gst_structure_id_get_value:
* @structure: a #GstStructure
* @field: the #GQuark of the field to get
*
* Get the value of the field with GQuark @field.
*
* Returns: the #GValue corresponding to the field with the given name
* identifier.
*/
const GValue *
gst_structure_id_get_value (const GstStructure * structure, GQuark field)
{
GstStructureField *gsfield;
g_return_val_if_fail (structure != NULL, NULL);
gsfield = gst_structure_id_get_field (structure, field);
if (gsfield == NULL)
return NULL;
return &gsfield->value;
}
/**
* gst_structure_remove_field:
* @structure: a #GstStructure
* @fieldname: the name of the field to remove
*
* Removes the field with the given name. If the field with the given
* name does not exist, the structure is unchanged.
*/
void
gst_structure_remove_field (GstStructure * structure, const gchar * fieldname)
{
GstStructureField *field;
GQuark id;
guint i;
g_return_if_fail (structure != NULL);
g_return_if_fail (fieldname != NULL);
g_return_if_fail (IS_MUTABLE (structure));
id = g_quark_from_string (fieldname);
for (i = 0; i < structure->fields->len; i++) {
field = GST_STRUCTURE_FIELD (structure, i);
if (field->name == id) {
if (G_IS_VALUE (&field->value)) {
g_value_unset (&field->value);
}
structure->fields = g_array_remove_index (structure->fields, i);
return;
}
}
}
/**
* gst_structure_remove_fields:
* @structure: a #GstStructure
* @fieldname: the name of the field to remove
* @...: NULL-terminated list of more fieldnames to remove
*
* Removes the fields with the given names. If a field does not exist, the
* argument is ignored.
*/
void
gst_structure_remove_fields (GstStructure * structure,
const gchar * fieldname, ...)
{
va_list varargs;
g_return_if_fail (structure != NULL);
g_return_if_fail (fieldname != NULL);
/* mutability checked in remove_field */
va_start (varargs, fieldname);
gst_structure_remove_fields_valist (structure, fieldname, varargs);
va_end (varargs);
}
/**
* gst_structure_remove_fields_valist:
* @structure: a #GstStructure
* @fieldname: the name of the field to remove
* @varargs: NULL-terminated list of more fieldnames to remove
*
* va_list form of #gst_structure_remove_fields.
*/
void
gst_structure_remove_fields_valist (GstStructure * structure,
const gchar * fieldname, va_list varargs)
{
gchar *field = (gchar *) fieldname;
g_return_if_fail (structure != NULL);
g_return_if_fail (fieldname != NULL);
/* mutability checked in remove_field */
while (field) {
gst_structure_remove_field (structure, field);
field = va_arg (varargs, char *);
}
}
/**
* gst_structure_remove_all_fields:
* @structure: a #GstStructure
*
* Removes all fields in a GstStructure.
*/
void
gst_structure_remove_all_fields (GstStructure * structure)
{
GstStructureField *field;
int i;
g_return_if_fail (structure != NULL);
g_return_if_fail (IS_MUTABLE (structure));
for (i = structure->fields->len - 1; i >= 0; i--) {
field = GST_STRUCTURE_FIELD (structure, i);
if (G_IS_VALUE (&field->value)) {
g_value_unset (&field->value);
}
structure->fields = g_array_remove_index (structure->fields, i);
}
}
/**
* gst_structure_get_field_type:
* @structure: a #GstStructure
* @fieldname: the name of the field
*
* 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.
*
* Returns: the #GValue of the field
*/
GType
gst_structure_get_field_type (const GstStructure * structure,
const gchar * fieldname)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, G_TYPE_INVALID);
g_return_val_if_fail (fieldname != NULL, G_TYPE_INVALID);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return G_TYPE_INVALID;
return G_VALUE_TYPE (&field->value);
}
/**
* gst_structure_n_fields:
* @structure: a #GstStructure
*
* Get the number of fields in the structure.
*
* Returns: the number of fields in the structure
*/
gint
gst_structure_n_fields (const GstStructure * structure)
{
g_return_val_if_fail (structure != NULL, 0);
return structure->fields->len;
}
/**
* gst_structure_nth_field_name:
* @structure: a #GstStructure
* @index: the index to get the name of
*
* Get the name of the given field number, counting from 0 onwards.
*
* Returns: the name of the given field number
*/
const gchar *
gst_structure_nth_field_name (const GstStructure * structure, guint index)
{
GstStructureField *field;
field = GST_STRUCTURE_FIELD (structure, index);
return g_quark_to_string (field->name);
}
/**
* gst_structure_foreach:
* @structure: a #GstStructure
* @func: a function to call for each field
* @user_data: private 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().
*
* Returns: TRUE if the supplied function returns TRUE For each of the fields,
* FALSE otherwise.
*/
gboolean
gst_structure_foreach (const GstStructure * structure,
GstStructureForeachFunc func, gpointer user_data)
{
guint i;
GstStructureField *field;
gboolean ret;
g_return_val_if_fail (structure != NULL, FALSE);
for (i = 0; i < structure->fields->len; i++) {
field = GST_STRUCTURE_FIELD (structure, i);
ret = func (field->name, &field->value, user_data);
if (!ret)
return FALSE;
}
return TRUE;
}
/**
* gst_structure_map_in_place:
* @structure: a #GstStructure
* @func: a function to call for each field
* @user_data: private data
*
* Calls the provided function once for each field in the #GstStructure. In
* contrast to gst_structure_foreach(), the function may modify the fields. The
* structure must be mutable.
*
* Returns: TRUE if the supplied function returns TRUE For each of the fields,
* FALSE otherwise.
*/
gboolean
gst_structure_map_in_place (GstStructure * structure,
GstStructureMapFunc func, gpointer user_data)
{
guint i;
GstStructureField *field;
gboolean ret;
g_return_val_if_fail (structure != NULL, FALSE);
g_return_val_if_fail (IS_MUTABLE (structure), FALSE);
for (i = 0; i < structure->fields->len; i++) {
field = GST_STRUCTURE_FIELD (structure, i);
ret = func (field->name, &field->value, user_data);
if (!ret)
return FALSE;
}
return TRUE;
}
/**
* gst_structure_has_field:
* @structure: a #GstStructure
* @fieldname: the name of a field
*
* Check if @structure contains a field named @fieldname.
*
* Returns: TRUE if the structure contains a field with the given name
*/
gboolean
gst_structure_has_field (const GstStructure * structure,
const gchar * fieldname)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, 0);
g_return_val_if_fail (fieldname != NULL, 0);
field = gst_structure_get_field (structure, fieldname);
return (field != NULL);
}
/**
* gst_structure_has_field_typed:
* @structure: a #GstStructure
* @fieldname: the name of a field
* @type: the type of a value
*
* Check if @structure contains a field named @fieldname and with GType @type.
*
* Returns: TRUE if the structure contains a field with the given name and type
*/
gboolean
gst_structure_has_field_typed (const GstStructure * structure,
const gchar * fieldname, GType type)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, 0);
g_return_val_if_fail (fieldname != NULL, 0);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return FALSE;
return (G_VALUE_TYPE (&field->value) == type);
}
/* utility functions */
/**
* gst_structure_get_boolean:
* @structure: a #GstStructure
* @fieldname: the name of a field
* @value: a pointer to a #gboolean to set
*
* 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.
*
* 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_boolean (const GstStructure * structure,
const gchar * fieldname, gboolean * value)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, FALSE);
g_return_val_if_fail (fieldname != NULL, FALSE);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return FALSE;
if (!G_VALUE_HOLDS_BOOLEAN (&field->value))
return FALSE;
*value = g_value_get_boolean (&field->value);
return TRUE;
}
/**
* gst_structure_get_int:
* @structure: a #GstStructure
* @fieldname: the name of a field
* @value: a pointer to an int to set
*
* 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.
*
* 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_int (const GstStructure * structure,
const gchar * fieldname, gint * value)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, FALSE);
g_return_val_if_fail (fieldname != NULL, FALSE);
g_return_val_if_fail (value != NULL, FALSE);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return FALSE;
if (!G_VALUE_HOLDS_INT (&field->value))
return FALSE;
*value = g_value_get_int (&field->value);
return TRUE;
}
/**
* gst_structure_get_fourcc:
* @structure: a #GstStructure
* @fieldname: the name of a field
* @value: a pointer to a #GstFourcc to set
*
* 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.
*
* 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_fourcc (const GstStructure * structure,
const gchar * fieldname, guint32 * value)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, FALSE);
g_return_val_if_fail (fieldname != NULL, FALSE);
g_return_val_if_fail (value != NULL, FALSE);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return FALSE;
if (!GST_VALUE_HOLDS_FOURCC (&field->value))
return FALSE;
*value = gst_value_get_fourcc (&field->value);
return TRUE;
}
/**
* gst_structure_get_date:
* @structure: a #GstStructure
* @fieldname: the name of a field
* @value: a pointer to a #GDate to set
*
* 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.
*
* 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_date (const GstStructure * structure, const gchar * fieldname,
GDate ** value)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, FALSE);
g_return_val_if_fail (fieldname != NULL, FALSE);
g_return_val_if_fail (value != NULL, FALSE);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return FALSE;
if (!GST_VALUE_HOLDS_DATE (&field->value))
return FALSE;
*value = g_value_dup_boxed (&field->value);
return TRUE;
}
/**
* gst_structure_get_clock_time:
* @structure: a #GstStructure
* @fieldname: the name of a field
* @value: a pointer to a #GstClockTime to set
*
* 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.
*
* 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_clock_time (const GstStructure * structure,
const gchar * fieldname, GstClockTime * value)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, FALSE);
g_return_val_if_fail (fieldname != NULL, FALSE);
g_return_val_if_fail (value != NULL, FALSE);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return FALSE;
if (!G_VALUE_HOLDS_UINT64 (&field->value))
return FALSE;
*value = g_value_get_uint64 (&field->value);
return TRUE;
}
/**
* gst_structure_get_double:
* @structure: a #GstStructure
* @fieldname: the name of a field
* @value: a pointer to a #GstFourcc to set
*
* 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.
*
* 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.
*/
gboolean
gst_structure_get_double (const GstStructure * structure,
const gchar * fieldname, gdouble * value)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, FALSE);
g_return_val_if_fail (fieldname != NULL, FALSE);
g_return_val_if_fail (value != NULL, FALSE);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return FALSE;
if (!G_VALUE_HOLDS_DOUBLE (&field->value))
return FALSE;
*value = g_value_get_double (&field->value);
return TRUE;
}
/**
* gst_structure_get_string:
* @structure: a #GstStructure
* @fieldname: the name of a field
*
* 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.
*
* Returns: a pointer to the string or NULL when the field did not exist
* or did not contain a string.
*/
const gchar *
gst_structure_get_string (const GstStructure * structure,
const gchar * fieldname)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, NULL);
g_return_val_if_fail (fieldname != NULL, NULL);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return NULL;
if (!G_VALUE_HOLDS_STRING (&field->value))
return NULL;
return g_value_get_string (&field->value);
}
/**
* gst_structure_get_enum:
* @structure: a #GstStructure
* @fieldname: the name of a field
* @enumtype: the enum type of a field
* @value: a pointer to an int to set
*
* 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.
*
* 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_enum (const GstStructure * structure,
const gchar * fieldname, GType enumtype, gint * value)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, FALSE);
g_return_val_if_fail (fieldname != NULL, FALSE);
g_return_val_if_fail (enumtype != G_TYPE_INVALID, FALSE);
g_return_val_if_fail (value != NULL, FALSE);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return FALSE;
if (!G_VALUE_HOLDS_ENUM (&field->value))
return FALSE;
if (!G_TYPE_CHECK_VALUE_TYPE (&field->value, enumtype))
return FALSE;
*value = g_value_get_enum (&field->value);
return TRUE;
}
/**
* gst_structure_get_fraction:
* @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
*
* 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.
*
* 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_get_fraction (const GstStructure * structure,
const gchar * fieldname, gint * value_numerator, gint * value_denominator)
{
GstStructureField *field;
g_return_val_if_fail (structure != NULL, FALSE);
g_return_val_if_fail (fieldname != NULL, FALSE);
g_return_val_if_fail (value_numerator != NULL, FALSE);
g_return_val_if_fail (value_denominator != NULL, FALSE);
field = gst_structure_get_field (structure, fieldname);
if (field == NULL)
return FALSE;
if (!GST_VALUE_HOLDS_FRACTION (&field->value))
return FALSE;
*value_numerator = gst_value_get_fraction_numerator (&field->value);
*value_denominator = gst_value_get_fraction_denominator (&field->value);
return TRUE;
}
typedef struct _GstStructureAbbreviation
{
char *type_name;
GType type;
}
GstStructureAbbreviation;
static GstStructureAbbreviation *
gst_structure_get_abbrs (gint * n_abbrs)
{
static GstStructureAbbreviation *abbrs = NULL;
static gint num = 0;
if (abbrs == NULL) {
/* dynamically generate the array */
GstStructureAbbreviation dyn_abbrs[] = {
{"int", G_TYPE_INT}
,
{"i", G_TYPE_INT}
,
{"float", G_TYPE_FLOAT}
,
{"f", G_TYPE_FLOAT}
,
{"double", G_TYPE_DOUBLE}
,
{"d", G_TYPE_DOUBLE}
,
{"buffer", GST_TYPE_BUFFER}
,
{"fourcc", GST_TYPE_FOURCC}
,
{"4", GST_TYPE_FOURCC}
,
{"fraction", GST_TYPE_FRACTION}
,
{"boolean", G_TYPE_BOOLEAN}
,
{"bool", G_TYPE_BOOLEAN}
,
{"b", G_TYPE_BOOLEAN}
,
{"string", G_TYPE_STRING}
,
{"str", G_TYPE_STRING}
,
{"s", G_TYPE_STRING}
};
num = G_N_ELEMENTS (dyn_abbrs);
/* permanently allocate and copy the array now */
abbrs = g_new0 (GstStructureAbbreviation, num);
memcpy (abbrs, dyn_abbrs, sizeof (GstStructureAbbreviation) * num);
}
*n_abbrs = num;
return abbrs;
}
static GType
gst_structure_from_abbr (const char *type_name)
{
int i;
GstStructureAbbreviation *abbrs;
gint n_abbrs;
g_return_val_if_fail (type_name != NULL, G_TYPE_INVALID);
abbrs = gst_structure_get_abbrs (&n_abbrs);
for (i = 0; i < n_abbrs; i++) {
if (strcmp (type_name, abbrs[i].type_name) == 0) {
return abbrs[i].type;
}
}
/* this is the fallback */
return g_type_from_name (type_name);
}
static const char *
gst_structure_to_abbr (GType type)
{
int i;
GstStructureAbbreviation *abbrs;
gint n_abbrs;
g_return_val_if_fail (type != G_TYPE_INVALID, NULL);
abbrs = gst_structure_get_abbrs (&n_abbrs);
for (i = 0; i < n_abbrs; i++) {
if (type == abbrs[i].type) {
return abbrs[i].type_name;
}
}
return g_type_name (type);
}
static GType
gst_structure_value_get_generic_type (GValue * val)
{
if (G_VALUE_TYPE (val) == GST_TYPE_LIST
|| G_VALUE_TYPE (val) == GST_TYPE_ARRAY) {
GArray *array = g_value_peek_pointer (val);
if (array->len > 0) {
GValue *value = &g_array_index (array, GValue, 0);
return gst_structure_value_get_generic_type (value);
} else {
return G_TYPE_INT;
}
} else if (G_VALUE_TYPE (val) == GST_TYPE_INT_RANGE) {
return G_TYPE_INT;
} else if (G_VALUE_TYPE (val) == GST_TYPE_DOUBLE_RANGE) {
return G_TYPE_DOUBLE;
} else if (G_VALUE_TYPE (val) == GST_TYPE_FRACTION_RANGE) {
return GST_TYPE_FRACTION;
}
return G_VALUE_TYPE (val);
}
#define GST_ASCII_IS_STRING(c) (g_ascii_isalnum((c)) || ((c) == '_') || \
((c) == '-') || ((c) == '+') || ((c) == '/') || ((c) == ':') || \
((c) == '.'))
/**
* gst_structure_to_string:
* @structure: a #GstStructure
*
* Converts @structure to a human-readable string representation.
*
* Returns: a pointer to string allocated by g_malloc(). g_free() after
* usage.
*/
gchar *
gst_structure_to_string (const GstStructure * structure)
{
GstStructureField *field;
GString *s;
guint i;
/* NOTE: This function is potentially called by the debug system,
* so any calls to gst_log() (and GST_DEBUG(), GST_LOG(), etc.)
* should be careful to avoid recursion. This includes any functions
* called by gst_structure_to_string. In particular, calls should
* not use the GST_PTR_FORMAT extension. */
g_return_val_if_fail (structure != NULL, NULL);
s = g_string_new ("");
/* FIXME this string may need to be escaped */
g_string_append_printf (s, "%s", g_quark_to_string (structure->name));
for (i = 0; i < structure->fields->len; i++) {
char *t;
GType type;
field = GST_STRUCTURE_FIELD (structure, i);
t = gst_value_serialize (&field->value);
type = gst_structure_value_get_generic_type (&field->value);
g_string_append_printf (s, ", %s=(%s)%s", g_quark_to_string (field->name),
gst_structure_to_abbr (type), GST_STR_NULL (t));
g_free (t);
}
return g_string_free (s, FALSE);
}
/*
* r will still point to the string. if end == next, the string will not be
* null-terminated. In all other cases it will be.
* end = pointer to char behind end of string, next = pointer to start of
* unread data.
* THIS FUNCTION MODIFIES THE STRING AND DETECTS INSIDE A NONTERMINATED STRING
*/
static gboolean
gst_structure_parse_string (gchar * s, gchar ** end, gchar ** next)
{
gchar *w;
if (*s == 0)
return FALSE;
if (*s != '"') {
int ret;
ret = gst_structure_parse_simple_string (s, end);
*next = *end;
return ret;
}
w = s;
s++;
while (*s != '"') {
if (*s == 0)
return FALSE;
if (*s == '\\') {
s++;
}
*w = *s;
w++;
s++;
}
s++;
*end = w;
*next = s;
return TRUE;
}
static gboolean
gst_structure_parse_range (gchar * s, gchar ** after, GValue * value,
GType type)
{
GValue value1 = { 0 };
GValue value2 = { 0 };
GType range_type;
gboolean ret;
if (*s != '[')
return FALSE;
s++;
ret = gst_structure_parse_value (s, &s, &value1, type);
if (ret == FALSE)
return FALSE;
while (g_ascii_isspace (*s))
s++;
if (*s != ',')
return FALSE;
s++;
while (g_ascii_isspace (*s))
s++;
ret = gst_structure_parse_value (s, &s, &value2, type);
if (ret == FALSE)
return FALSE;
while (g_ascii_isspace (*s))
s++;
if (*s != ']')
return FALSE;
s++;
if (G_VALUE_TYPE (&value1) != G_VALUE_TYPE (&value2))
return FALSE;
if (G_VALUE_TYPE (&value1) == G_TYPE_DOUBLE) {
range_type = GST_TYPE_DOUBLE_RANGE;
g_value_init (value, range_type);
gst_value_set_double_range (value, g_value_get_double (&value1),
g_value_get_double (&value2));
} else if (G_VALUE_TYPE (&value1) == G_TYPE_INT) {
range_type = GST_TYPE_INT_RANGE;
g_value_init (value, range_type);
gst_value_set_int_range (value, g_value_get_int (&value1),
g_value_get_int (&value2));
} else if (G_VALUE_TYPE (&value1) == GST_TYPE_FRACTION) {
range_type = GST_TYPE_FRACTION_RANGE;
g_value_init (value, range_type);
gst_value_set_fraction_range (value, &value1, &value2);
} else {
return FALSE;
}
*after = s;
return TRUE;
}
static gboolean
gst_structure_parse_any_list (gchar * s, gchar ** after, GValue * value,
GType type, GType list_type, char begin, char end)
{
GValue list_value = { 0 };
gboolean ret;
GArray *array;
g_value_init (value, list_type);
array = g_value_peek_pointer (value);
if (*s != begin)
return FALSE;
s++;
while (g_ascii_isspace (*s))
s++;
if (*s == end) {
s++;
*after = s;
return TRUE;
}
ret = gst_structure_parse_value (s, &s, &list_value, type);
if (ret == FALSE)
return FALSE;
g_array_append_val (array, list_value);
while (g_ascii_isspace (*s))
s++;
while (*s != end) {
if (*s != ',')
return FALSE;
s++;
while (g_ascii_isspace (*s))
s++;
memset (&list_value, 0, sizeof (list_value));
ret = gst_structure_parse_value (s, &s, &list_value, type);
if (ret == FALSE)
return FALSE;
g_array_append_val (array, list_value);
while (g_ascii_isspace (*s))
s++;
}
s++;
*after = s;
return TRUE;
}
static gboolean
gst_structure_parse_list (gchar * s, gchar ** after, GValue * value, GType type)
{
return gst_structure_parse_any_list (s, after, value, type, GST_TYPE_LIST,
'{', '}');
}
static gboolean
gst_structure_parse_array (gchar * s, gchar ** after, GValue * value,
GType type)
{
return gst_structure_parse_any_list (s, after, value, type,
GST_TYPE_ARRAY, '<', '>');
}
static gboolean
gst_structure_parse_simple_string (gchar * str, gchar ** end)
{
char *s = str;
while (GST_ASCII_IS_STRING (*s)) {
s++;
}
*end = s;
return (s != str);
}
static gboolean
gst_structure_parse_field (gchar * str,
gchar ** after, GstStructureField * field)
{
gchar *name;
gchar *name_end;
gchar *s;
gchar c;
s = str;
while (g_ascii_isspace (*s) || (s[0] == '\\' && g_ascii_isspace (s[1])))
s++;
name = s;
if (!gst_structure_parse_simple_string (s, &name_end))
return FALSE;
s = name_end;
while (g_ascii_isspace (*s) || (s[0] == '\\' && g_ascii_isspace (s[1])))
s++;
if (*s != '=')
return FALSE;
s++;
c = *name_end;
*name_end = 0;
field->name = g_quark_from_string (name);
*name_end = c;
if (!gst_structure_parse_value (s, &s, &field->value, G_TYPE_INVALID))
return FALSE;
*after = s;
return TRUE;
}
static gboolean
gst_structure_parse_value (gchar * str,
gchar ** after, GValue * value, GType default_type)
{
gchar *type_name;
gchar *type_end;
gchar *value_s;
gchar *value_end;
gchar *s;
gchar c;
int ret = 0;
GType type = default_type;
s = str;
while (g_ascii_isspace (*s))
s++;
type_name = NULL;
if (*s == '(') {
type = G_TYPE_INVALID;
s++;
while (g_ascii_isspace (*s))
s++;
type_name = s;
if (!gst_structure_parse_simple_string (s, &type_end))
return FALSE;
s = type_end;
while (g_ascii_isspace (*s))
s++;
if (*s != ')')
return FALSE;
s++;
while (g_ascii_isspace (*s))
s++;
c = *type_end;
*type_end = 0;
type = gst_structure_from_abbr (type_name);
*type_end = c;
if (type == G_TYPE_INVALID)
return FALSE;
}
while (g_ascii_isspace (*s))
s++;
if (*s == '[') {
ret = gst_structure_parse_range (s, &s, value, type);
} else if (*s == '{') {
ret = gst_structure_parse_list (s, &s, value, type);
} else if (*s == '<') {
ret = gst_structure_parse_array (s, &s, value, type);
} else {
value_s = s;
if (!gst_structure_parse_string (s, &value_end, &s))
return FALSE;
c = *value_end;
*value_end = 0;
if (type == G_TYPE_INVALID) {
GType try_types[] =
{ G_TYPE_INT, G_TYPE_DOUBLE, GST_TYPE_FRACTION, G_TYPE_STRING };
int i;
for (i = 0; i < 4; i++) {
g_value_init (value, try_types[i]);
ret = gst_value_deserialize (value, value_s);
if (ret)
break;
g_value_unset (value);
}
} else {
g_value_init (value, type);
ret = gst_value_deserialize (value, value_s);
}
*value_end = c;
}
*after = s;
return ret;
}
/**
* gst_structure_from_string:
* @string: a string representation of a #GstStructure.
* @end: pointer to store the end of the string in.
*
* 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.
*
* Returns: a new #GstStructure or NULL when the string could not
* be parsed. Free after usage.
*/
GstStructure *
gst_structure_from_string (const gchar * string, gchar ** end)
{
char *name;
char *copy;
char *w;
char *r;
char save;
GstStructure *structure = NULL;
GstStructureField field = { 0 };
g_return_val_if_fail (string != NULL, NULL);
copy = g_strdup (string);
r = copy;
name = r;
if (!gst_structure_parse_string (r, &w, &r))
goto error;
while (g_ascii_isspace (*r) || (r[0] == '\\' && g_ascii_isspace (r[1])))
r++;
if (*r != 0 && *r != ';' && *r != ',')
goto error;
save = *w;
*w = 0;
structure = gst_structure_empty_new (name);
*w = save;
while (*r && (*r != ';')) {
if (*r != ',')
goto error;
r++;
while (*r && (g_ascii_isspace (*r) || (r[0] == '\\'
&& g_ascii_isspace (r[1]))))
r++;
memset (&field, 0, sizeof (field));
if (!gst_structure_parse_field (r, &r, &field))
goto error;
gst_structure_set_field (structure, &field);
while (*r && (g_ascii_isspace (*r) || (r[0] == '\\'
&& g_ascii_isspace (r[1]))))
r++;
}
if (end)
*end = (char *) string + (r - copy);
g_free (copy);
return structure;
error:
if (structure)
gst_structure_free (structure);
g_free (copy);
return NULL;
}
static void
gst_structure_transform_to_string (const GValue * src_value,
GValue * dest_value)
{
g_return_if_fail (src_value != NULL);
g_return_if_fail (dest_value != NULL);
dest_value->data[0].v_pointer =
gst_structure_to_string (src_value->data[0].v_pointer);
}
static GstStructure *
gst_structure_copy_conditional (const GstStructure * structure)
{
if (structure)
return gst_structure_copy (structure);
return NULL;
}
/* fixate utility functions */
/**
* gst_structure_fixate_field_nearest_int:
* @structure: a #GstStructure
* @field_name: a field in @structure
* @target: the target value of the fixation
*
* Fixates a #GstStructure by changing the given field to the nearest
* integer to @target that is a subset of the existing field.
*
* Returns: TRUE if the structure could be fixated
*/
gboolean
gst_structure_fixate_field_nearest_int (GstStructure * structure,
const char *field_name, int target)
{
const GValue *value;
g_return_val_if_fail (gst_structure_has_field (structure, field_name), FALSE);
g_return_val_if_fail (IS_MUTABLE (structure), FALSE);
value = gst_structure_get_value (structure, field_name);
if (G_VALUE_TYPE (value) == G_TYPE_INT) {
/* already fixed */
return FALSE;
} else if (G_VALUE_TYPE (value) == GST_TYPE_INT_RANGE) {
int x;
x = gst_value_get_int_range_min (value);
if (target < x)
target = x;
x = gst_value_get_int_range_max (value);
if (target > x)
target = x;
gst_structure_set (structure, field_name, G_TYPE_INT, target, NULL);
return TRUE;
} else if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
const GValue *list_value;
int i, n;
int best = 0;
int best_index = -1;
n = gst_value_list_get_size (value);
for (i = 0; i < n; i++) {
list_value = gst_value_list_get_value (value, i);
if (G_VALUE_TYPE (list_value) == G_TYPE_INT) {
int x = g_value_get_int (list_value);
if (best_index == -1 || (ABS (target - x) < ABS (target - best))) {
best_index = i;
best = x;
}
}
}
if (best_index != -1) {
gst_structure_set (structure, field_name, G_TYPE_INT, best, NULL);
return TRUE;
}
return FALSE;
}
return FALSE;
}
/**
* gst_structure_fixate_field_nearest_double:
* @structure: a #GstStructure
* @field_name: a field in @structure
* @target: the target value of the fixation
*
* Fixates a #GstStructure by changing the given field to the nearest
* double to @target that is a subset of the existing field.
*
* Returns: TRUE if the structure could be fixated
*/
gboolean
gst_structure_fixate_field_nearest_double (GstStructure * structure,
const char *field_name, double target)
{
const GValue *value;
g_return_val_if_fail (gst_structure_has_field (structure, field_name), FALSE);
g_return_val_if_fail (IS_MUTABLE (structure), FALSE);
value = gst_structure_get_value (structure, field_name);
if (G_VALUE_TYPE (value) == G_TYPE_DOUBLE) {
/* already fixed */
return FALSE;
} else if (G_VALUE_TYPE (value) == GST_TYPE_DOUBLE_RANGE) {
double x;
x = gst_value_get_double_range_min (value);
if (target < x)
target = x;
x = gst_value_get_double_range_max (value);
if (target > x)
target = x;
gst_structure_set (structure, field_name, G_TYPE_DOUBLE, target, NULL);
return TRUE;
} else if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
const GValue *list_value;
int i, n;
double best = 0;
int best_index = -1;
n = gst_value_list_get_size (value);
for (i = 0; i < n; i++) {
list_value = gst_value_list_get_value (value, i);
if (G_VALUE_TYPE (list_value) == G_TYPE_DOUBLE) {
double x = g_value_get_double (list_value);
if (best_index == -1 || (ABS (target - x) < ABS (target - best))) {
best_index = i;
best = x;
}
}
}
if (best_index != -1) {
gst_structure_set (structure, field_name, G_TYPE_DOUBLE, best, NULL);
return TRUE;
}
return FALSE;
}
return FALSE;
}
/**
* gst_structure_fixate_field_boolean:
* @structure: a #GstStructure
* @field_name: a field in @structure
* @target: the target value of the fixation
*
* Fixates a #GstStructure by changing the given @field_name field to the given
* @target boolean if that field is not fixed yet.
*
* Returns: TRUE if the structure could be fixated
*/
gboolean
gst_structure_fixate_field_boolean (GstStructure * structure,
const char *field_name, gboolean target)
{
const GValue *value;
g_return_val_if_fail (gst_structure_has_field (structure, field_name), FALSE);
g_return_val_if_fail (IS_MUTABLE (structure), FALSE);
value = gst_structure_get_value (structure, field_name);
if (G_VALUE_TYPE (value) == G_TYPE_BOOLEAN) {
/* already fixed */
return FALSE;
} else if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
const GValue *list_value;
int i, n;
int best = 0;
int best_index = -1;
n = gst_value_list_get_size (value);
for (i = 0; i < n; i++) {
list_value = gst_value_list_get_value (value, i);
if (G_VALUE_TYPE (list_value) == G_TYPE_BOOLEAN) {
gboolean x = g_value_get_boolean (list_value);
if (best_index == -1 || x == target) {
best_index = i;
best = x;
}
}
}
if (best_index != -1) {
gst_structure_set (structure, field_name, G_TYPE_BOOLEAN, best, NULL);
return TRUE;
}
return FALSE;
}
return FALSE;
}
/**
* gst_structure_fixate_field_nearest_fraction:
* @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
*
* 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.
*
* 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)
{
const GValue *value;
g_return_val_if_fail (gst_structure_has_field (structure, field_name), FALSE);
g_return_val_if_fail (IS_MUTABLE (structure), FALSE);
value = gst_structure_get_value (structure, field_name);
if (G_VALUE_TYPE (value) == GST_TYPE_FRACTION) {
/* already fixed */
return FALSE;
} else if (G_VALUE_TYPE (value) == GST_TYPE_FRACTION_RANGE) {
const GValue *x, *new_value;
GValue target = { 0 };
g_value_init (&target, GST_TYPE_FRACTION);
gst_value_set_fraction (&target, target_numerator, target_denominator);
new_value = &target;
x = gst_value_get_fraction_range_min (value);
if (gst_value_compare (&target, x) == GST_VALUE_LESS_THAN)
new_value = x;
x = gst_value_get_fraction_range_max (value);
if (gst_value_compare (&target, x) == GST_VALUE_GREATER_THAN)
new_value = x;
gst_structure_set_value (structure, field_name, new_value);
g_value_unset (&target);
return TRUE;
} else if (G_VALUE_TYPE (value) == GST_TYPE_LIST) {
const GValue *list_value;
int i, n;
const GValue *best = NULL;
GValue best_diff = { 0 };
GValue cur_diff = { 0 };
GValue target = { 0 };
gboolean res = FALSE;
g_value_init (&best_diff, GST_TYPE_FRACTION);
g_value_init (&cur_diff, GST_TYPE_FRACTION);
g_value_init (&target, GST_TYPE_FRACTION);
gst_value_set_fraction (&target, target_numerator, target_denominator);
n = gst_value_list_get_size (value);
for (i = 0; i < n; i++) {
list_value = gst_value_list_get_value (value, i);
if (G_VALUE_TYPE (list_value) == GST_TYPE_FRACTION) {
if (best == NULL) {
best = list_value;
gst_value_set_fraction (&best_diff, 0, 1);
} else {
if (gst_value_compare (list_value, &target) == GST_VALUE_LESS_THAN)
gst_value_fraction_subtract (&cur_diff, &target, list_value);
else
gst_value_fraction_subtract (&cur_diff, list_value, &target);
if (gst_value_compare (&cur_diff, &best_diff) == GST_VALUE_LESS_THAN) {
best = list_value;
g_value_copy (&cur_diff, &best_diff);
}
}
}
}
if (best != NULL) {
gst_structure_set_value (structure, field_name, best);
res = TRUE;
}
g_value_unset (&best_diff);
g_value_unset (&cur_diff);
g_value_unset (&target);
return res;
}
return FALSE;
}