--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/gstreamer_core/gst/gststructure.c Thu Dec 17 08:53:32 2009 +0200
@@ -0,0 +1,2527 @@
+/* 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. 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().
+ *
+ * Last reviewed on 2007-10-16 (0.10.15)
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <string.h>
+
+#include "gst_private.h"
+#include <gst/gst.h>
+#include <gobject/gvaluecollector.h>
+
+#ifdef __SYMBIAN32__
+#include <glib_global.h>
+#endif
+
+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);
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+GType
+gst_structure_get_type (void)
+{
+ static GType gst_structure_type = 0;
+
+ if (G_UNLIKELY (gst_structure_type == 0)) {
+ 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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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);
+}
+
+static gboolean
+gst_structure_validate_name (const gchar * name)
+{
+ const gchar *s;
+
+ g_return_val_if_fail (name != NULL, FALSE);
+
+ /* FIXME 0.11: use g_ascii_isalpha() */
+ if (!g_ascii_isalnum (*name)) {
+ GST_WARNING ("Invalid character '%c' at offset 0 in structure name: %s",
+ *name, name);
+ return FALSE;
+ }
+
+ /* FIXME 0.11: don't allow spaces */
+ /* FIXME: test name string more */
+ s = &name[1];
+ while (*s && (g_ascii_isalnum (*s) || strchr ("/-_.:+ ", *s) != NULL))
+ s++;
+ if (*s != '\0') {
+ GST_WARNING ("Invalid character '%c' at offset %lu in structure name: %s",
+ *s, ((gulong) s - (gulong) name), name);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ * gst_structure_empty_new:
+ * @name: name of new structure
+ *
+ * Creates a new, empty #GstStructure with the given @name.
+ *
+ * See gst_structure_set_name() for constraints on the @name parameter.
+ *
+ * Returns: a new, empty #GstStructure
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstStructure *
+gst_structure_empty_new (const gchar * name)
+{
+ g_return_val_if_fail (gst_structure_validate_name (name), 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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+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().
+ *
+ * See gst_structure_set_name() for constraints on the @name parameter.
+ *
+ * Returns: a new #GstStructure
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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);
+
+ if (structure)
+ 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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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);
+
+ /* getting the string is cheap and comparing short strings is too
+ * should be faster than getting the quark for name and comparing the quarks
+ */
+ 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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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. It must not be empty, start with a
+ * letter and can be followed by letters, numbers and any of "/-_.:".
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_structure_set_name (GstStructure * structure, const gchar * name)
+{
+ g_return_if_fail (structure != NULL);
+ g_return_if_fail (IS_MUTABLE (structure));
+ g_return_if_fail (gst_structure_validate_name (name));
+
+ 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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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));
+
+ if (G_VALUE_HOLDS_STRING (value)) {
+ const gchar *s;
+
+ s = g_value_get_string (value);
+ if (G_UNLIKELY (s != NULL && !g_utf8_validate (s, -1, NULL))) {
+ g_warning ("Trying to set string field '%s' on structure, but string is "
+ "not valid UTF-8. Please file a bug.", g_quark_to_string (field));
+ return;
+ }
+ }
+
+ 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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+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().
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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 (type == G_TYPE_DATE) {
+ g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
+ type = GST_TYPE_DATE;
+ }
+
+ 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 *);
+ }
+}
+
+/**
+ * gst_structure_id_set:
+ * @structure: a #GstStructure
+ * @fieldname: the GQuark for the name of the field to set
+ * @...: variable arguments
+ *
+ * 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.
+ *
+ * Since: 0.10.10
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_structure_id_set (GstStructure * structure, GQuark field, ...)
+{
+ va_list varargs;
+
+ g_return_if_fail (structure != NULL);
+
+ va_start (varargs, field);
+ gst_structure_id_set_valist (structure, field, varargs);
+ va_end (varargs);
+}
+
+/**
+ * gst_structure_id_set_valist:
+ * @structure: a #GstStructure
+ * @fieldname: the name of the field to set
+ * @varargs: variable arguments
+ *
+ * va_list form of gst_structure_id_set().
+ *
+ * Since: 0.10.10
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_structure_id_set_valist (GstStructure * structure,
+ GQuark 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 = fieldname;
+
+ type = va_arg (varargs, GType);
+
+ if (type == G_TYPE_DATE) {
+ g_warning ("Don't use G_TYPE_DATE, use GST_TYPE_DATE instead\n");
+ type = GST_TYPE_DATE;
+ }
+
+ 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, GQuark);
+ }
+}
+
+/* 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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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().
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+const gchar *
+gst_structure_nth_field_name (const GstStructure * structure, guint index)
+{
+ GstStructureField *field;
+
+ g_return_val_if_fail (structure != NULL, NULL);
+ g_return_val_if_fail (index < structure->fields->len, NULL);
+
+ 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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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);
+ g_return_val_if_fail (func != 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 but not delete the
+ * fields. The structure must be mutable.
+ *
+ * Returns: TRUE if the supplied function returns TRUE For each of the fields,
+ * FALSE otherwise.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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);
+ g_return_val_if_fail (func != 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_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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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_uint:
+ * @structure: a #GstStructure
+ * @fieldname: the name of a field
+ * @value: a pointer to a uint to set
+ *
+ * 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.
+ *
+ * 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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_structure_get_uint (const GstStructure * structure,
+ const gchar * fieldname, guint * 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_UINT (&field->value))
+ return FALSE;
+
+ *value = g_value_get_uint (&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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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;
+
+/* return a copy of an array of GstStructureAbbreviation containing all the
+ * known type_string, GType maps, including abbreviations for common types */
+static GstStructureAbbreviation *
+gst_structure_get_abbrs (gint * n_abbrs)
+{
+ static GstStructureAbbreviation *abbrs = NULL;
+ static gint num = 0;
+
+ if (abbrs == NULL) {
+ /* dynamically generate the array */
+ #ifdef __SYMBIAN32__
+
+ 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", G_TYPE_INVALID}
+ ,
+ {"fourcc", G_TYPE_INVALID}
+ ,
+ {"4", G_TYPE_INVALID}
+ ,
+ {"fraction", G_TYPE_INVALID}
+ ,
+ {"boolean", G_TYPE_BOOLEAN}
+ ,
+ {"bool", G_TYPE_BOOLEAN}
+ ,
+ {"b", G_TYPE_BOOLEAN}
+ ,
+ {"string", G_TYPE_STRING}
+ ,
+ {"str", G_TYPE_STRING}
+ ,
+ {"s", G_TYPE_STRING}
+ };
+
+ dyn_abbrs[6].type= GST_TYPE_BUFFER;
+
+ dyn_abbrs[7].type= GST_TYPE_FOURCC;
+
+ dyn_abbrs[8].type= GST_TYPE_FOURCC;
+
+ dyn_abbrs[9].type= GST_TYPE_FRACTION;
+
+
+
+ #else
+ 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}
+ ,
+ {"structure", GST_TYPE_STRUCTURE}
+ };
+ #endif
+ 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;
+}
+
+/* given a type_name that could be a type abbreviation or a registered GType,
+ * return a matching GType */
+static GType
+gst_structure_gtype_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);
+}
+
+/* keep in sync with gstvalue.c */
+#define GST_ASCII_IS_STRING(c) (g_ascii_isalnum((c)) || ((c) == '_') || \
+ ((c) == '-') || ((c) == '+') || ((c) == '/') || ((c) == ':') || \
+ ((c) == '.'))
+
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+priv_gst_structure_append_to_gstring (const GstStructure * structure,
+ GString * s)
+{
+ GstStructureField *field;
+ guint i;
+
+ g_return_val_if_fail (s != NULL, FALSE);
+
+ g_string_append (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_len (s, ", ", 2);
+ /* FIXME: do we need to escape fieldnames? */
+ g_string_append (s, g_quark_to_string (field->name));
+ g_string_append_len (s, "=(", 2);
+ g_string_append (s, gst_structure_to_abbr (type));
+ g_string_append_c (s, ')');
+ g_string_append (s, GST_STR_NULL (t));
+ g_free (t);
+ }
+
+ g_string_append_c (s, ';');
+ return TRUE;
+}
+
+/**
+ * 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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gchar *
+gst_structure_to_string (const GstStructure * structure)
+{
+ GString *s;
+
+ /* 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);
+
+ /* we estimate a minimum size based on the number of fields in order to
+ * avoid unnecessary reallocs within GString */
+ s = g_string_sized_new (STRUCTURE_ESTIMATED_STRING_LEN (structure));
+ priv_gst_structure_append_to_gstring (structure, s);
+ 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;
+ #ifdef __SYMBIAN32__
+ int i;
+ #endif
+ GType type = default_type;
+
+
+ s = str;
+ while (g_ascii_isspace (*s))
+ s++;
+
+ /* check if there's a (type_name) 'cast' */
+ 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_gtype_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) {
+ #ifdef __SYMBIAN32__
+ GType try_types[] =
+ { G_TYPE_INT, G_TYPE_DOUBLE, G_TYPE_INVALID, G_TYPE_STRING };
+ try_types[2] =GST_TYPE_FRACTION;
+
+ #else
+ GType try_types[] =
+ { G_TYPE_INT, G_TYPE_DOUBLE, GST_TYPE_FRACTION, G_TYPE_STRING };
+
+ int i;
+ #endif
+ for (i = 0; i < G_N_ELEMENTS (try_types); 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 with gst_structure_free() after use.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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;
+
+ /* skip spaces (FIXME: _isspace treats tabs and newlines as space!) */
+ while (*r && (g_ascii_isspace (*r) || (r[0] == '\\'
+ && g_ascii_isspace (r[1]))))
+ r++;
+
+ name = r;
+ if (!gst_structure_parse_string (r, &w, &r)) {
+ GST_WARNING ("Failed to parse structure string");
+ goto error;
+ }
+
+ save = *w;
+ *w = 0;
+ structure = gst_structure_empty_new (name);
+ *w = save;
+
+ if (structure == NULL)
+ goto error;
+
+ do {
+ while (*r && (g_ascii_isspace (*r) || (r[0] == '\\'
+ && g_ascii_isspace (r[1]))))
+ r++;
+ if (*r == ';') {
+ /* end of structure, get the next char and finish */
+ r++;
+ break;
+ }
+ if (*r == '\0') {
+ /* accept \0 as end delimiter */
+ break;
+ }
+ if (*r != ',') {
+ GST_WARNING ("Failed to find delimiter, r=%s", 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 (TRUE);
+
+ if (end)
+ *end = (char *) string + (r - copy);
+ else if (*r)
+ g_warning ("gst_structure_from_string did not consume whole string,"
+ " but caller did not provide end pointer (\"%s\")", string);
+
+ 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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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 = ⌖
+ 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);
+
+ best = NULL;
+
+ 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 (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 (!best
+ || 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;
+}