gstreamer/ges/ges-extractable.c
2020-03-05 17:04:51 -03:00

346 lines
11 KiB
C

/* GStreamer Editing Services
*
* Copyright (C) 2012 Thibault Saunier <thibault.saunier@collabora.com>
* Copyright (C) 2012 Volodymyr Rudyi <vladimir.rudoy@gmail.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.
*/
/**
* SECTION: gesextractable
* @title: GESExtractable Interface
* @short_description: An interface for objects which can be extracted
* from a #GESAsset
*
* A #GObject that implements the #GESExtractable interface can be
* extracted from a #GESAsset using ges_asset_extract().
*
* Each extractable type will have its own way of interpreting the
* #GESAsset:id of an asset (or, if it is associated with a specific
* subclass of #GESAsset, the asset subclass may handle the
* interpretation of the #GESAsset:id). By default, the requested asset
* #GESAsset:id will be ignored by a #GESExtractable and will be set to
* the type name of the extractable instead. Also by default, when the
* requested asset is extracted, the returned object will simply be a
* newly created default object of that extractable type. You should check
* the documentation for each extractable type to see if they differ from
* the default.
*
* After the object is extracted, it will have a reference to the asset it
* came from, which you can retrieve using ges_extractable_get_asset().
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "ges-asset.h"
#include "ges-internal.h"
#include "ges-extractable.h"
#include "ges-uri-clip.h"
static GQuark ges_asset_key;
G_DEFINE_INTERFACE_WITH_CODE (GESExtractable, ges_extractable,
G_TYPE_INITIALLY_UNOWNED,
ges_asset_key = g_quark_from_static_string ("ges-extractable-data"));
static gchar *
ges_extractable_check_id_default (GType type, const gchar * id, GError ** error)
{
return g_strdup (g_type_name (type));
}
static GType
ges_extractable_get_real_extractable_type_default (GType type, const gchar * id)
{
return type;
}
G_GNUC_BEGIN_IGNORE_DEPRECATIONS; /* Start ignoring GParameter deprecation */
static GParameter *
extractable_get_parameters_from_id (const gchar * id, guint * n_params)
{
*n_params = 0;
return NULL;
}
G_GNUC_END_IGNORE_DEPRECATIONS; /* End ignoring GParameter deprecation */
static gchar *
extractable_get_id (GESExtractable * self)
{
return g_strdup (g_type_name (G_OBJECT_TYPE (self)));
}
static void
ges_extractable_default_init (GESExtractableInterface * iface)
{
iface->asset_type = GES_TYPE_ASSET;
iface->check_id = ges_extractable_check_id_default;
iface->get_real_extractable_type =
ges_extractable_get_real_extractable_type_default;
iface->get_parameters_from_id = extractable_get_parameters_from_id;
iface->set_asset = NULL;
iface->set_asset_full = NULL;
iface->get_id = extractable_get_id;
iface->register_metas = NULL;
iface->can_update_asset = FALSE;
}
/**
* ges_extractable_get_asset:
* @self: A #GESExtractable
*
* Get the asset that has been set on the extractable object.
*
* Returns: (transfer none) (nullable): The asset set on @self, or %NULL
* if no asset has been set.
*/
GESAsset *
ges_extractable_get_asset (GESExtractable * self)
{
g_return_val_if_fail (GES_IS_EXTRACTABLE (self), NULL);
return g_object_get_qdata (G_OBJECT (self), ges_asset_key);;
}
/**
* ges_extractable_set_asset:
* @self: A #GESExtractable
* @asset: (transfer none): The asset to set
*
* Sets the asset for this extractable object.
*
* When an object is extracted from an asset using ges_asset_extract() its
* asset will be automatically set. Note that many classes that implement
* #GESExtractable will automatically create their objects using assets
* when you call their @new methods. However, you can use this method to
* associate an object with a compatible asset if it was created by other
* means and does not yet have an asset. Or, for some implementations of
* #GESExtractable, you can use this to change the asset of the given
* extractable object, which will lead to a change in its state to
* match the new asset #GESAsset:id.
*
* Returns: %TRUE if @asset could be successfully set on @self.
*/
gboolean
ges_extractable_set_asset (GESExtractable * self, GESAsset * asset)
{
GESExtractableInterface *iface;
g_return_val_if_fail (GES_IS_EXTRACTABLE (self), FALSE);
iface = GES_EXTRACTABLE_GET_INTERFACE (self);
GST_DEBUG_OBJECT (self, "Setting asset to %" GST_PTR_FORMAT, asset);
if (iface->can_update_asset == FALSE &&
g_object_get_qdata (G_OBJECT (self), ges_asset_key)) {
GST_WARNING_OBJECT (self, "Can not reset asset on object");
/* FIXME: do not fail if the same asset */
return FALSE;
}
/* FIXME: shouldn't we check that the extractable-type of the asset
* matches our type? */
g_object_set_qdata_full (G_OBJECT (self), ges_asset_key,
gst_object_ref (asset), gst_object_unref);
/* Let classes that implement the interface know that a asset has been set */
if (iface->set_asset_full)
/* FIXME: return to the previous asset if the setting fails */
return iface->set_asset_full (self, asset);
if (iface->set_asset)
iface->set_asset (self, asset);
return TRUE;
}
/**
* ges_extractable_get_id:
* @self: A #GESExtractable
*
* Gets the #GESAsset:id of some associated asset. It may be the case
* that the object has no set asset, or even that such an asset does not
* yet exist in the GES cache. Instead, this will return the asset
* #GESAsset:id that is _compatible_ with the current state of the object,
* as determined by the #GESExtractable implementer. If it was indeed
* extracted from an asset, this should return the same as its
* corresponding asset #GESAsset:id.
*
* Returns: (transfer full): The #GESAsset:id of some associated #GESAsset
* that is compatible with @self's current state.
*/
gchar *
ges_extractable_get_id (GESExtractable * self)
{
g_return_val_if_fail (GES_IS_EXTRACTABLE (self), NULL);
return GES_EXTRACTABLE_GET_INTERFACE (self)->get_id (self);
}
G_GNUC_BEGIN_IGNORE_DEPRECATIONS; /* Start ignoring GParameter deprecation */
/**
* ges_extractable_type_get_parameters_for_id:
* @type: The #GType implementing #GESExtractable
* @id: The ID of the Extractable
* @n_params: (out): Return location for the returned array
*
* Returns: (transfer full) (array length=n_params): an array of #GParameter
* needed to extract the #GESExtractable from a #GESAsset of @id
*/
GParameter *
ges_extractable_type_get_parameters_from_id (GType type, const gchar * id,
guint * n_params)
{
GObjectClass *klass;
GESExtractableInterface *iface;
GParameter *ret = NULL;
g_return_val_if_fail (g_type_is_a (type, G_TYPE_OBJECT), NULL);
g_return_val_if_fail (g_type_is_a (type, GES_TYPE_EXTRACTABLE), NULL);
klass = g_type_class_ref (type);
iface = g_type_interface_peek (klass, GES_TYPE_EXTRACTABLE);
ret = iface->get_parameters_from_id (id, n_params);
g_type_class_unref (klass);
return ret;
}
G_GNUC_END_IGNORE_DEPRECATIONS; /* End ignoring GParameter deprecation */
/**
* ges_extractable_type_get_asset_type:
* @type: The #GType implementing #GESExtractable
*
* Get the #GType, subclass of #GES_TYPE_ASSET to instanciate
* to be able to extract a @type
*
* Returns: the #GType to use to create a asset to extract @type
*/
GType
ges_extractable_type_get_asset_type (GType type)
{
GObjectClass *klass;
GESExtractableInterface *iface;
g_return_val_if_fail (g_type_is_a (type, G_TYPE_OBJECT), G_TYPE_INVALID);
g_return_val_if_fail (g_type_is_a (type, GES_TYPE_EXTRACTABLE),
G_TYPE_INVALID);
klass = g_type_class_ref (type);
iface = g_type_interface_peek (klass, GES_TYPE_EXTRACTABLE);
g_type_class_unref (klass);
return iface->asset_type;
}
/**
* ges_extractable_type_check_id:
* @type: The #GType implementing #GESExtractable
* @id: The ID to check
*
* Check if @id is valid for @type
*
* Returns: (transfer full) (nullable): A newly allocated string containing
* the actual ID (after some processing) or %NULL if the ID is wrong.
*/
gchar *
ges_extractable_type_check_id (GType type, const gchar * id, GError ** error)
{
GObjectClass *klass;
GESExtractableInterface *iface;
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
g_return_val_if_fail (g_type_is_a (type, G_TYPE_OBJECT), NULL);
g_return_val_if_fail (g_type_is_a (type, GES_TYPE_EXTRACTABLE), NULL);
klass = g_type_class_ref (type);
iface = g_type_interface_peek (klass, GES_TYPE_EXTRACTABLE);
g_type_class_unref (klass);
return iface->check_id (type, id, error);
}
/**
* ges_extractable_get_real_extractable_type:
* @type: The #GType implementing #GESExtractable
* @id: The ID to check
*
* Get the #GType that should be used as extractable_type for @type and
* @id. Usually this will be the same as @type but in some cases they can
* be some subclasses of @type. For example, in the case of #GESFormatter,
* the returned #GType will be a subclass of #GESFormatter that can be used
* to load the file pointed by @id.
*
* Returns: Return the #GESExtractable type that should be used for @id
*/
GType
ges_extractable_get_real_extractable_type_for_id (GType type, const gchar * id)
{
GType ret;
GObjectClass *klass;
GESExtractableInterface *iface;
klass = g_type_class_ref (type);
iface = g_type_interface_peek (klass, GES_TYPE_EXTRACTABLE);
g_type_class_unref (klass);
ret = iface->get_real_extractable_type (type, id);
GST_DEBUG ("Extractable type for id %s and wanted type %s is: %s",
id, g_type_name (type), g_type_name (ret));
return ret;
}
/**
* ges_extractable_register_metas:
* @self: A #GESExtractable
* @asset: The #GESAsset on which metadatas should be registered
*
* Lets you register standard method for @extractable_type on @asset
*
* Returns: %TRUE if metas could be register %FALSE otherwize
*/
gboolean
ges_extractable_register_metas (GType extractable_type, GESAsset * asset)
{
GObjectClass *klass;
gboolean ret = FALSE;
GESExtractableInterface *iface;
g_return_val_if_fail (g_type_is_a (extractable_type, GES_TYPE_EXTRACTABLE),
FALSE);
klass = g_type_class_ref (extractable_type);
iface = g_type_interface_peek (klass, GES_TYPE_EXTRACTABLE);
if (iface->register_metas)
ret = iface->register_metas (iface, klass, asset);
g_type_class_unref (klass);
return ret;
}