gstreamer/ges/ges-meta-container.c
2014-10-26 20:25:46 +00:00

910 lines
28 KiB
C

/* GStreamer Editing Services
* Copyright (C) 2012 Paul Lange <palango@gmx.de>
* Copyright (C) <2014> Thibault Saunier <thibault.saunier@collabora.com>
*
* 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.
*/
#include <glib-object.h>
#include <gst/gst.h>
#include "ges-meta-container.h"
/**
* SECTION: gesmetacontainer
* @short_description: An interface for storing meta
*
* Interface that allows reading and writing meta
*/
static GQuark ges_meta_key;
G_DEFINE_INTERFACE_WITH_CODE (GESMetaContainer, ges_meta_container,
G_TYPE_OBJECT, ges_meta_key =
g_quark_from_static_string ("ges-meta-container-data"););
enum
{
NOTIFY_SIGNAL,
LAST_SIGNAL
};
static guint _signals[LAST_SIGNAL] = { 0 };
typedef struct RegisteredMeta
{
GType item_type;
GESMetaFlag flags;
} RegisteredMeta;
typedef struct ContainerData
{
GstStructure *structure;
GHashTable *static_items;
} ContainerData;
static void
ges_meta_container_default_init (GESMetaContainerInterface * iface)
{
/**
* GESMetaContainer::notify:
* @container: a #GESMetaContainer
* @prop: the key of the value that changed
* @value: the #GValue containing the new value
*
* The notify signal is used to be notify of changes of values
* of some metadatas
*/
_signals[NOTIFY_SIGNAL] =
g_signal_new ("notify-meta", G_TYPE_FROM_INTERFACE (iface),
G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
G_SIGNAL_NO_HOOKS, 0, NULL, NULL, g_cclosure_marshal_generic,
G_TYPE_NONE, 2, G_TYPE_STRING, G_TYPE_VALUE);
}
static void
_free_meta_container_data (ContainerData * data)
{
gst_structure_free (data->structure);
g_hash_table_unref (data->static_items);
g_slice_free (ContainerData, data);
}
static void
_free_static_item (RegisteredMeta * item)
{
g_slice_free (RegisteredMeta, item);
}
static ContainerData *
_create_container_data (GESMetaContainer * container)
{
ContainerData *data = g_slice_new (ContainerData);
data->structure = gst_structure_new_empty ("metadatas");
data->static_items = g_hash_table_new_full (g_str_hash, g_str_equal,
g_free, (GDestroyNotify) (GDestroyNotify) _free_static_item);
g_object_set_qdata_full (G_OBJECT (container), ges_meta_key, data,
(GDestroyNotify) _free_meta_container_data);
return data;
}
static GstStructure *
_meta_container_get_structure (GESMetaContainer * container)
{
ContainerData *data;
data = g_object_get_qdata (G_OBJECT (container), ges_meta_key);
if (!data)
data = _create_container_data (container);
return data->structure;
}
typedef struct
{
GESMetaForeachFunc func;
const GESMetaContainer *container;
gpointer data;
} MetadataForeachData;
static void
structure_foreach_wrapper (GQuark field_id, const GValue * value,
gpointer user_data)
{
MetadataForeachData *data = (MetadataForeachData *) user_data;
data->func (data->container, g_quark_to_string (field_id), value, data->data);
}
static gboolean
_append_foreach (GQuark field_id, const GValue * value, GESMetaContainer * self)
{
ges_meta_container_set_meta (self, g_quark_to_string (field_id), value);
return TRUE;
}
/**
* ges_meta_container_foreach:
* @container: container to iterate over
* @func: (scope call): function to be called for each metadata
* @user_data: (closure): user specified data
*
* Calls the given function for each metadata inside the meta container. Note
* that if there is no metadata, the function won't be called at all.
*/
void
ges_meta_container_foreach (GESMetaContainer * container,
GESMetaForeachFunc func, gpointer user_data)
{
GstStructure *structure;
MetadataForeachData foreach_data;
g_return_if_fail (GES_IS_META_CONTAINER (container));
g_return_if_fail (func != NULL);
structure = _meta_container_get_structure (container);
foreach_data.func = func;
foreach_data.container = container;
foreach_data.data = user_data;
gst_structure_foreach (structure,
(GstStructureForeachFunc) structure_foreach_wrapper, &foreach_data);
}
/* _can_write_value should have been checked before calling */
static gboolean
_register_meta (GESMetaContainer * container, GESMetaFlag flags,
const gchar * meta_item, GType type)
{
ContainerData *data;
RegisteredMeta *static_item;
data = g_object_get_qdata (G_OBJECT (container), ges_meta_key);
if (!data)
data = _create_container_data (container);
else if (g_hash_table_lookup (data->static_items, meta_item)) {
GST_WARNING_OBJECT (container, "Static meta %s already registered",
meta_item);
return FALSE;
}
static_item = g_slice_new0 (RegisteredMeta);
static_item->item_type = type;
static_item->flags = flags;
g_hash_table_insert (data->static_items, g_strdup (meta_item), static_item);
return TRUE;
}
static gboolean
_set_value (GESMetaContainer * container, const gchar * meta_item,
const GValue * value)
{
GstStructure *structure;
gchar *val = gst_value_serialize (value);
if (val == NULL) {
GST_WARNING_OBJECT (container, "Could not set value on item: %s",
meta_item);
g_free (val);
return FALSE;
}
structure = _meta_container_get_structure (container);
GST_DEBUG_OBJECT (container, "Setting meta_item %s value: %s::%s",
meta_item, G_VALUE_TYPE_NAME (value), val);
gst_structure_set_value (structure, meta_item, value);
g_signal_emit (container, _signals[NOTIFY_SIGNAL], 0, meta_item, value);
g_free (val);
return TRUE;
}
static gboolean
_can_write_value (GESMetaContainer * container, const gchar * item_name,
GType type)
{
ContainerData *data;
RegisteredMeta *static_item = NULL;
data = g_object_get_qdata (G_OBJECT (container), ges_meta_key);
if (!data) {
_create_container_data (container);
return TRUE;
}
static_item = g_hash_table_lookup (data->static_items, item_name);
if (static_item == NULL)
return TRUE;
if ((static_item->flags & GES_META_WRITABLE) == FALSE) {
GST_WARNING_OBJECT (container, "Can not write %s", item_name);
return FALSE;
}
if (static_item->item_type != type) {
GST_WARNING_OBJECT (container, "Can not set value of type %s on %s "
"its type is: %s", g_type_name (static_item->item_type), item_name,
g_type_name (type));
return FALSE;
}
return TRUE;
}
#define CREATE_SETTER(name, value_ctype, value_gtype, setter_name) \
gboolean \
ges_meta_container_set_ ## name (GESMetaContainer *container, \
const gchar *meta_item, value_ctype value) \
{ \
GValue gval = { 0 }; \
gboolean ret; \
\
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE); \
g_return_val_if_fail (meta_item != NULL, FALSE); \
\
if (_can_write_value (container, meta_item, value_gtype) == FALSE) \
return FALSE; \
\
g_value_init (&gval, value_gtype); \
g_value_set_ ##setter_name (&gval, value); \
\
ret = _set_value (container, meta_item, &gval); \
g_value_unset (&gval); \
return ret; \
}
/**
* ges_meta_container_set_boolean:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
CREATE_SETTER (boolean, gboolean, G_TYPE_BOOLEAN, boolean)
/**
* ges_meta_container_set_int:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: Value to set
*
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
CREATE_SETTER (int, gint, G_TYPE_INT, int)
/**
* ges_meta_container_set_uint:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: Value to set
*
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
CREATE_SETTER (uint, guint, G_TYPE_UINT, uint)
/**
* ges_meta_container_set_int64:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: Value to set
*
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
CREATE_SETTER (int64, gint64, G_TYPE_INT64, int64)
/**
* ges_meta_container_set_uint64:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: Value to set
*
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
CREATE_SETTER (uint64, guint64, G_TYPE_UINT64, uint64)
/**
* ges_meta_container_set_float:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: Value to set
*
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
CREATE_SETTER (float, float, G_TYPE_FLOAT, float)
/**
* ges_meta_container_set_double:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: Value to set
*
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
CREATE_SETTER (double, double, G_TYPE_DOUBLE, double)
/**
* ges_meta_container_set_date:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: Value to set
*
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
CREATE_SETTER (date, const GDate *, G_TYPE_DATE, boxed)
/**
* ges_meta_container_set_date_time:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: Value to set
*
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
CREATE_SETTER (date_time, const GstDateTime *, GST_TYPE_DATE_TIME, boxed)
/**
* ges_meta_container_set_string:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: Value to set
*
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
CREATE_SETTER (string, const gchar *, G_TYPE_STRING, string)
/**
* ges_meta_container_set_meta:
* @container: Target container
* @meta_item: Name of the meta item to set
* @value: Value to set
* Sets the value of a given meta item
*
* Return: %TRUE if the meta could be added, %FALSE otherwize
*/
gboolean
ges_meta_container_set_meta (GESMetaContainer * container,
const gchar * meta_item, const GValue * value)
{
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE);
g_return_val_if_fail (meta_item != NULL, FALSE);
if (_can_write_value (container, meta_item, G_VALUE_TYPE (value)) == FALSE)
return FALSE;
return _set_value (container, meta_item, value);
}
/**
* ges_meta_container_metas_to_string:
* @container: a #GESMetaContainer
*
* Serializes a meta container to a string.
*
* Returns: a newly-allocated string, or NULL in case of an error. The
* string must be freed with g_free() when no longer needed.
*/
gchar *
ges_meta_container_metas_to_string (GESMetaContainer * container)
{
GstStructure *structure;
g_return_val_if_fail (GES_IS_META_CONTAINER (container), NULL);
structure = _meta_container_get_structure (container);
return gst_structure_to_string (structure);
}
/**
* ges_meta_container_add_metas_from_string:
* @str: a string created with ges_meta_container_metas_to_string()
* @container: Target container
*
* Deserializes a meta container.
*
* Returns: (transfer full): a new #GESMetaContainer, or NULL in case of an
* error.
*/
gboolean
ges_meta_container_add_metas_from_string (GESMetaContainer * container,
const gchar * str)
{
GstStructure *n_structure;
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE);
n_structure = gst_structure_from_string (str, NULL);
if (n_structure == NULL) {
GST_WARNING_OBJECT (container, "Could not add metas: %s", str);
return FALSE;
}
gst_structure_foreach (n_structure, (GstStructureForeachFunc) _append_foreach,
container);
gst_structure_free (n_structure);
return TRUE;
}
#define CREATE_REGISTER_STATIC(name, value_ctype, value_gtype, setter_name) \
gboolean \
ges_meta_container_register_meta_ ## name (GESMetaContainer *container,\
GESMetaFlag flags, const gchar *meta_item, value_ctype value) \
{ \
gboolean ret; \
GValue gval = { 0 }; \
\
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE); \
g_return_val_if_fail (meta_item != NULL, FALSE); \
\
if (!_register_meta (container, flags, meta_item, value_gtype)) \
return FALSE; \
\
g_value_init (&gval, value_gtype); \
g_value_set_ ##setter_name (&gval, value); \
\
ret = _set_value (container, meta_item, &gval); \
\
g_value_unset (&gval); \
return ret; \
}
/**
* register_meta_:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the meta could be register, %FALSE otherwize
*/
CREATE_REGISTER_STATIC (boolean, gboolean, G_TYPE_BOOLEAN, boolean)
/**
* ges_meta_container_register_meta_int:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the meta could be register, %FALSE otherwize
*/
CREATE_REGISTER_STATIC (int, gint, G_TYPE_INT, int)
/**
* ges_meta_container_register_meta_uint:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the meta could be register, %FALSE otherwize
*/
CREATE_REGISTER_STATIC (uint, guint, G_TYPE_UINT, uint)
/**
* ges_meta_container_register_meta_int64:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the meta could be register, %FALSE otherwize
*/
CREATE_REGISTER_STATIC (int64, gint64, G_TYPE_INT64, int64)
/**
* ges_meta_container_register_meta_uint64:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the meta could be register, %FALSE otherwize
*/
CREATE_REGISTER_STATIC (uint64, guint64, G_TYPE_UINT64, uint64)
/**
* ges_meta_container_register_meta_float:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the meta could be register, %FALSE otherwize
*/
CREATE_REGISTER_STATIC (float, float, G_TYPE_FLOAT, float)
/**
* ges_meta_container_register_meta_double:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the meta could be register, %FALSE otherwize
*/
CREATE_REGISTER_STATIC (double, double, G_TYPE_DOUBLE, double)
/**
* ges_meta_container_register_meta_date:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the meta could be register, %FALSE otherwize
*/
CREATE_REGISTER_STATIC (date, const GDate *, G_TYPE_DATE, boxed)
/**
* ges_meta_container_register_meta_date_time:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the meta could be register, %FALSE otherwize
*/
CREATE_REGISTER_STATIC (date_time, const GstDateTime *, GST_TYPE_DATE_TIME,
boxed)
/**
* ges_meta_container_register_meta_string:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: (allow-none): Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the meta could be register, %FALSE otherwize
*/
CREATE_REGISTER_STATIC (string, const gchar *, G_TYPE_STRING, string)
/**
* ges_meta_container_register_meta:
* @container: Target container
* @flags: The #GESMetaFlag to be used
* @meta_item: Name of the meta item to set
* @value: Value to set
*
* Sets a static meta on @container. This method lets you define static
* metadatas, which means that the type of the registered will be the only
* type accepted for this meta on that particular @container.
*
* Return: %TRUE if the static meta could be added, %FALSE otherwize
*/
gboolean
ges_meta_container_register_meta (GESMetaContainer * container,
GESMetaFlag flags, const gchar * meta_item, const GValue * value)
{
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE);
g_return_val_if_fail (meta_item != NULL, FALSE);
if (!_register_meta (container, flags, meta_item, G_VALUE_TYPE (value)))
return FALSE;
return _set_value (container, meta_item, value);
}
gboolean
ges_meta_container_check_meta_registered (GESMetaContainer * container,
const gchar * meta_item, GESMetaFlag * flags, GType * type)
{
ContainerData *data;
RegisteredMeta *static_item;
data = g_object_get_qdata (G_OBJECT (container), ges_meta_key);
if (!data)
return FALSE;
static_item = g_hash_table_lookup (data->static_items, meta_item);
if (static_item == NULL) {
GST_WARNING_OBJECT (container, "Static meta %s already registered",
meta_item);
return FALSE;
}
if (type)
*type = static_item->item_type;
if (flags)
*flags = static_item->flags;
return TRUE;
}
/* Copied from gsttaglist.c */
/***** evil macros to get all the *_get_* functions right *****/
#define CREATE_GETTER(name,type) \
gboolean \
ges_meta_container_get_ ## name (GESMetaContainer *container, \
const gchar *meta_item, type value) \
{ \
GstStructure *structure; \
\
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE); \
g_return_val_if_fail (meta_item != NULL, FALSE); \
g_return_val_if_fail (value != NULL, FALSE); \
\
structure = _meta_container_get_structure (container); \
\
return gst_structure_get_ ## name (structure, meta_item, value); \
}
/**
* ges_meta_container_get_boolean:
* @container: Target container
* @meta_item: Name of the meta item to get
* @dest: (out): Destination to which value of meta item will be copied
* Gets the value of a given meta item, returns NULL if @meta_item
* can not be found.
*/
CREATE_GETTER (boolean, gboolean *);
/**
* ges_meta_container_get_int:
* @container: Target container
* @meta_item: Name of the meta item to get
* @dest: (out): Destination to which value of meta item will be copied
* Gets the value of a given meta item, returns NULL if @meta_item
* can not be found.
*/
CREATE_GETTER (int, gint *);
/**
* ges_meta_container_get_uint:
* @container: Target container
* @meta_item: Name of the meta item to get
* @dest: (out): Destination to which value of meta item will be copied
* Gets the value of a given meta item, returns NULL if @meta_item
* can not be found.
*/
CREATE_GETTER (uint, guint *);
/**
* ges_meta_container_get_double:
* @container: Target container
* @meta_item: Name of the meta item to get
* @dest: (out): Destination to which value of meta item will be copied
* Gets the value of a given meta item, returns NULL if @meta_item
* can not be found.
*/
CREATE_GETTER (double, gdouble *);
/**
* ges_meta_container_get_int64:
* @container: Target container
* @meta_item: Name of the meta item to get
* @dest: (out): Destination to which value of meta item will be copied
* Gets the value of a given meta item, returns %FALSE if @meta_item
* can not be found.
*/
gboolean
ges_meta_container_get_int64 (GESMetaContainer * container,
const gchar * meta_item, gint64 * dest)
{
GstStructure *structure;
const GValue *value;
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE);
g_return_val_if_fail (meta_item != NULL, FALSE);
g_return_val_if_fail (dest != NULL, FALSE);
structure = _meta_container_get_structure (container);
value = gst_structure_get_value (structure, meta_item);
if (!value || G_VALUE_TYPE (value) != G_TYPE_INT64)
return FALSE;
*dest = g_value_get_int64 (value);
return TRUE;
}
/**
* ges_meta_container_get_uint64:
* @container: Target container
* @meta_item: Name of the meta item to get
* @dest: (out): Destination to which value of meta item will be copied
* Gets the value of a given meta item, returns NULL if @meta_item
* can not be found.
*/
gboolean
ges_meta_container_get_uint64 (GESMetaContainer * container,
const gchar * meta_item, guint64 * dest)
{
GstStructure *structure;
const GValue *value;
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE);
g_return_val_if_fail (meta_item != NULL, FALSE);
g_return_val_if_fail (dest != NULL, FALSE);
structure = _meta_container_get_structure (container);
value = gst_structure_get_value (structure, meta_item);
if (!value || G_VALUE_TYPE (value) != G_TYPE_UINT64)
return FALSE;
*dest = g_value_get_uint64 (value);
return TRUE;
}
/**
* ges_meta_container_get_float:
* @container: Target container
* @meta_item: Name of the meta item to get
* @dest: (out): Destination to which value of meta item will be copied
* Gets the value of a given meta item, returns FALSE if @meta_item
* can not be found.
*/
gboolean
ges_meta_container_get_float (GESMetaContainer * container,
const gchar * meta_item, gfloat * dest)
{
GstStructure *structure;
const GValue *value;
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE);
g_return_val_if_fail (meta_item != NULL, FALSE);
g_return_val_if_fail (dest != NULL, FALSE);
structure = _meta_container_get_structure (container);
value = gst_structure_get_value (structure, meta_item);
if (!value || G_VALUE_TYPE (value) != G_TYPE_FLOAT)
return FALSE;
*dest = g_value_get_float (value);
return TRUE;
}
/**
* ges_meta_container_get_string:
* @container: Target container
* @meta_item: Name of the meta item to get
* Gets the value of a given meta item, returns NULL if @meta_item
* can not be found.
*/
const gchar *
ges_meta_container_get_string (GESMetaContainer * container,
const gchar * meta_item)
{
GstStructure *structure;
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE);
g_return_val_if_fail (meta_item != NULL, FALSE);
structure = _meta_container_get_structure (container);
return gst_structure_get_string (structure, meta_item);
}
/**
* ges_meta_container_get_meta:
* @container: Target container
* @key: Get the key name of the meta to retrieve
*
* Gets the value of a given meta item, returns NULL if @meta_item
* can not be found.
*
* Returns: %TRUE if the vale could be optained %FALSE otherwize
*/
const GValue *
ges_meta_container_get_meta (GESMetaContainer * container, const gchar * key)
{
GstStructure *structure;
g_return_val_if_fail (GES_IS_META_CONTAINER (container), FALSE);
g_return_val_if_fail (key != NULL, FALSE);
structure = _meta_container_get_structure (container);
return gst_structure_get_value (structure, key);
}
/**
* ges_meta_container_get_date:
* @container: Target container
* @meta_item: Name of the meta item to get
* @dest: (out): Destination to which value of meta item will be copied
* Gets the value of a given meta item, returns NULL if @meta_item
* can not be found.
*/
CREATE_GETTER (date, GDate **);
/**
* ges_meta_container_get_date_time:
* @container: Target container
* @meta_item: Name of the meta item to get
* @dest: (out): Destination to which value of meta item will be copied
* Gets the value of a given meta item, returns NULL if @meta_item
* can not be found.
*/
CREATE_GETTER (date_time, GstDateTime **);