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docs: update GESAsset

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Henry Wilkes 2020-01-17 12:20:11 +00:00 committed by Thibault Saunier
parent b3d44f66b7
commit dfe3b805f3
2 changed files with 308 additions and 122 deletions
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402
ges/ges-asset.c
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@ -21,16 +21,22 @@
/**
* SECTION: gesasset
* @title: GESAsset
* @short_description: Represents usable resources inside the GStreamer Editing Services
* @short_description: Represents usable resources inside the GStreamer
* Editing Services
*
* The Assets in the GStreamer Editing Services represent the resources
* that can be used. You can create assets for any type that implements the #GESExtractable
* interface, for example #GESClips, #GESFormatter, and #GESTrackElement do implement it.
* This means that assets will represent for example a #GESUriClips, #GESBaseEffect etc,
* and then you can extract objects of those types with the appropriate parameters from the asset
* using the #ges_asset_extract method:
* A #GESAsset in the GStreamer Editing Services represents a resources
* that can be used. In particular, any class that implements the
* #GESExtractable interface may have some associated assets with a
* corresponding #GESAsset:extractable-type, from which its objects can be
* extracted using ges_asset_extract(). Some examples would be
* #GESClip, #GESFormatter and #GESTrackElement.
*
* |[
* All assets that are created within GES are stored in a cache; one per
* each #GESAsset:id and #GESAsset:extractable-type pair. These assets can
* be fetched, and initialized if they do not yet exist in the cache,
* using ges_asset_request().
*
* ``` c
* GESAsset *effect_asset;
* GESEffect *effect;
*
@ -40,27 +46,22 @@
* // And now you can extract an instance of GESEffect from that asset
* effect = GES_EFFECT (ges_asset_extract (effect_asset));
*
* ]|
* ```
*
* In that example, the advantages of having a #GESAsset are that you can know what effects
* you are working with and let your user know about the avalaible ones, you can add metadata
* to the #GESAsset through the #GESMetaContainer interface and you have a model for your
* custom effects. Note that #GESAsset management is making easier thanks to the #GESProject class.
* The advantage of using assets, rather than simply creating the object
* directly, is that the currently loaded resources can be listed with
* ges_list_assets() and displayed to an end user. For example, to show
* which media files have been loaded, and a standard list of effects. In
* fact, the GES library already creates assets for #GESTransitionClip and
* #GESFormatter, which you can use to list all the available transition
* types and supported formats.
*
* Each asset is represented by a pair of @extractable_type and @id (string). Actually the @extractable_type
* is the type that implements the #GESExtractable interface, that means that for example for a #GESUriClip,
* the type that implements the #GESExtractable interface is #GESClip.
* The identifier represents different things depending on the @extractable_type and you should check
* the documentation of each type to know what the ID of #GESAsset actually represents for that type. By default,
* we only have one #GESAsset per type, and the @id is the name of the type, but this behaviour is overriden
* to be more useful. For example, for GESTransitionClips, the ID is the vtype of the transition
* you will extract from it (ie crossfade, box-wipe-rc etc..) For #GESEffect the ID is the
* @bin-description property of the extracted objects (ie the gst-launch style description of the bin that
* will be used).
* The other advantage is that #GESAsset implements #GESMetaContainer, so
* metadata can be set on the asset, with some subclasses automatically
* creating this metadata on initiation.
*
* Each and every #GESAsset is cached into GES, and you can query those with the #ges_list_assets function.
* Also the system will automatically register #GESAssets for #GESFormatters and #GESTransitionClips
* and standard effects (actually not implemented yet) and you can simply query those calling:
* For example, to display information about the supported formats, you
* could do the following:
* |[
* GList *formatter_assets, *tmp;
*
@ -70,17 +71,52 @@
* // Print some infos about the formatter GESAsset
* for (tmp = formatter_assets; tmp; tmp = tmp->next) {
* g_print ("Name of the formatter: %s, file extension it produces: %s",
* ges_meta_container_get_string (GES_META_CONTAINER (tmp->data), GES_META_FORMATTER_NAME),
* ges_meta_container_get_string (GES_META_CONTAINER (tmp->data), GES_META_FORMATTER_EXTENSION));
* ges_meta_container_get_string (
* GES_META_CONTAINER (tmp->data), GES_META_FORMATTER_NAME),
* ges_meta_container_get_string (
* GES_META_CONTAINER (tmp->data), GES_META_FORMATTER_EXTENSION));
* }
*
* g_list_free (transition_assets);
*
* ]|
*
* You can request the creation of #GESAssets using either ges_asset_request() or
* ges_asset_request_async(). All the #GESAssets are cached and thus any asset that has already
* been created can be requested again without overhead.
* ## ID
*
* Each asset is uniquely defined in the cache by its
* #GESAsset:extractable-type and #GESAsset:id. Depending on the
* #GESAsset:extractable-type, the #GESAsset:id can be used to parametrise
* the creation of the object upon extraction. By default, a class that
* implements #GESExtractable will only have a single associated asset,
* with an #GESAsset:id set to the type name of its objects. However, this
* is overwritten by some implementations, which allow a class to have
* multiple associated assets. For example, for #GESTransitionClip the
* #GESAsset:id will be a nickname of the #GESTransitionClip:vtype. You
* should check the documentation for each extractable type to see if they
* differ from the default.
*
* Moreover, each #GESAsset:extractable-type may also associate itself
* with a specific asset subclass. In such cases, when their asset is
* requested, an asset of this subclass will be returned instead.
*
* ## Managing
*
* You can use a #GESProject to easily manage the assets of a
* #GESTimeline.
*
* ## Proxies
*
* Some assets can (temporarily) act as the #GESAsset:proxy of another
* asset. When the original asset is requested from the cache, the proxy
* will be returned in its place. This can be useful if, say, you want
* to substitute a #GESUriClipAsset corresponding to a high resolution
* media file with the asset of a lower resolution stand in.
*
* An asset may even have several proxies, the first of which will act as
* its default and be returned on requests, but the others will be ordered
* to take its place once it is removed. You can add a proxy to an asset,
* or set its default, using ges_asset_set_proxy(), and you can remove
* them with ges_asset_unproxy().
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
@ -206,6 +242,9 @@ _check_and_update_parameters (GType * extractable_type, const gchar * id,
return real_id;
}
/* FIXME: why are we not accepting a GError ** error argument, which we
* could pass to ges_asset_cache_set_loaded ()? Which would allow the
* error to be set for the GInitable init method below */
static gboolean
start_loading (GESAsset * asset)
{
@ -218,6 +257,8 @@ static gboolean
initable_init (GInitable * initable, GCancellable * cancellable,
GError ** error)
{
/* FIXME: Is there actually a reason to be freeing the GError that
* error points to? */
g_clear_error (error);
return start_loading (GES_ASSET (initable));
@ -257,6 +298,10 @@ async_initable_init_async (GAsyncInitable * initable, gint io_priority,
}
case GES_ASSET_LOADING_ASYNC:
/* If Async.... let it go */
/* FIXME: how are user subclasses that implement ->start_loading
* to return GES_ASSET_LOADING_ASYNC meant to invoke the private
* method ges_asset_cache_set_loaded once they finish initializing?
*/
break;
}
}
@ -374,6 +419,8 @@ ges_asset_set_property (GObject * object, guint property_id,
switch (property_id) {
case PROP_TYPE:
asset->priv->extractable_type = g_value_get_gtype (value);
/* NOTE: we calling this in the setter so metadata is set on the
* asset upon initiation, but before it has been loaded. */
ges_extractable_register_metas (asset->priv->extractable_type, asset);
break;
case PROP_ID:
@ -383,6 +430,8 @@ ges_asset_set_property (GObject * object, guint property_id,
ges_asset_set_proxy (asset, g_value_get_object (value));
break;
case PROP_PROXY_TARGET:
/* FIXME: Need to remove self as a proxy from the previous target
* and only call the below when the new target is not NULL */
ges_asset_set_proxy (g_value_get_object (value), asset);
break;
default:
@ -421,20 +470,54 @@ ges_asset_class_init (GESAssetClass * klass)
object_class->set_property = ges_asset_set_property;
object_class->finalize = ges_asset_finalize;
/**
* GESAsset:extractable-type:
*
* The #GESExtractable object type that can be extracted from the asset.
*/
_properties[PROP_TYPE] =
g_param_spec_gtype ("extractable-type", "Extractable type",
"The type of the Object that can be extracted out of the asset",
G_TYPE_OBJECT, G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE);
/**
* GESAsset:id:
*
* The ID of the asset. This should be unique amongst all assets with
* the same #GESAsset:extractable-type. Depending on the associated
* #GESExtractable implementation, this id may convey some information
* about the #GObject that should be extracted. Note that, as such, the
* ID will have an expected format, and you can not choose this value
* arbitrarily. By default, this will be set to the type name of the
* #GESAsset:extractable-type, but you should check the documentation
* of the extractable type to see whether they differ from the
* default behaviour.
*/
_properties[PROP_ID] =
g_param_spec_string ("id", "Identifier",
"The unic identifier of the asset", NULL,
"The unique identifier of the asset", NULL,
G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE);
/**
* GESAsset:proxy:
*
* The default proxy for this asset, or %NULL if it has no proxy. A
* proxy will act as a substitute for the original asset when the
* original is requested (see ges_asset_request()).
*
* Setting this property will not remove the existing proxy, but will
* replace it as the default (see ges_asset_set_proxy()).
*/
_properties[PROP_PROXY] =
g_param_spec_object ("proxy", "Proxy",
"The asset default proxy.", GES_TYPE_ASSET, G_PARAM_READWRITE);
/**
* GESAsset:proxy-target:
*
* The asset that this asset is a proxy of, or %NULL if it is not a
* proxy for another asset.
*/
_properties[PROP_PROXY_TARGET] =
g_param_spec_object ("proxy-target", "Proxy target",
"The target of a proxy asset.", GES_TYPE_ASSET, G_PARAM_READWRITE);
@ -445,6 +528,7 @@ ges_asset_class_init (GESAssetClass * klass)
klass->extract = ges_asset_extract_default;
klass->request_id_update = ges_asset_request_id_update_default;
klass->inform_proxy = NULL;
/* FIXME: ->proxied vmethod unset */
GST_DEBUG_CATEGORY_INIT (ges_asset_debug, "ges-asset",
GST_DEBUG_FG_BLUE | GST_DEBUG_BOLD, "GES Asset");
@ -715,6 +799,9 @@ ges_asset_try_proxy (GESAsset * asset, const gchar * new_id)
asset->priv->state = ASSET_PROXIED;
asset->priv->proxied_asset_id = g_strdup (new_id);
/* FIXME: inform_proxy is not used consistently. For example, it is
* not called in set_proxy. However, it is still used by GESUriAsset.
* We should find some other method */
class = GES_ASSET_GET_CLASS (asset);
if (class->inform_proxy)
GES_ASSET_GET_CLASS (asset)->inform_proxy (asset, new_id);
@ -733,17 +820,24 @@ _lookup_proxied_asset (const gchar * id, GESAssetCacheEntry * entry,
/**
* ges_asset_set_proxy:
* @asset: The #GESAsset to set proxy on
* @proxy: (allow-none): The #GESAsset that should be used as default proxy for @asset or
* %NULL if you want to use the currently set proxy. Note that an asset can proxy one and only
* one other asset.
* @asset: The #GESAsset to proxy
* @proxy: (allow-none): A new default proxy for @asset
*
* A proxying asset is an asset that can substitue the real @asset. For example if you
* have a full HD #GESUriClipAsset you might want to set a lower resolution (HD version
* of the same file) as proxy. Note that when an asset is proxied, calling
* #ges_asset_request will actually return the proxy asset.
* Sets one asset as the default #GESAsset:proxy of another (the
* original asset).
*
* Returns: %TRUE if @proxy has been set on @asset, %FALSE otherwise.
* If the given proxy is among the existing proxies of the asset (see
* ges_asset_list_proxies()) it will be moved to become the default
* proxy. Otherwise, the proxy will be added to the list of proxies, as
* the new default. The previous default proxy will become 'next in line'
* for if the new one is removed, and so on. As such, this method will
* **not** actually remove the previous default proxy
* (use ges_asset_unproxy() for that).
*
* Note that an asset can only act as a proxy for one other asset.
*
* Returns: %TRUE if @proxy was successfully set as the default for
* @asset.
*/
gboolean
ges_asset_set_proxy (GESAsset * asset, GESAsset * proxy)
@ -776,6 +870,8 @@ ges_asset_set_proxy (GESAsset * asset, GESAsset * proxy)
return TRUE;
}
/* FIXME: why are we allowing for a NULL asset? What is the desired
* behaviour? */
if (asset == NULL) {
GHashTable *entries_table;
GESAssetCacheEntry *entry;
@ -837,18 +933,26 @@ ges_asset_set_proxy (GESAsset * asset, GESAsset * proxy)
asset->priv->state = ASSET_PROXIED;
g_object_notify_by_pspec (G_OBJECT (asset), _properties[PROP_PROXY]);
/* FIXME: ->inform_proxy is not called. We should figure out what the
* purpose of ->inform_proxy should be generically. Currently, it is
* only called in ges_asset_try_proxy! */
return TRUE;
}
/**
* ges_asset_unproxy:
* @asset: The #GESAsset to stop proxying with @proxy
* @proxy: The #GESAsset to stop considering as a proxy for @asset
* @asset: The #GESAsset to no longer proxy with @proxy
* @proxy: An existing proxy of @asset
*
* Removes @proxy from the list of known proxies for @asset.
* If @proxy was the current proxy for @asset, stop using it.
* Removes the proxy from the available list of proxies for the asset. If
* the given proxy is the default proxy of the list, then the next proxy
* in the available list (see ges_asset_list_proxies()) will become the
* default. If there are no other proxies, then the asset will no longer
* have a default #GESAsset:proxy.
*
* Returns: %TRUE if @proxy was a known proxy for @asset, %FALSE otherwise.
* Returns: %TRUE if @proxy was successfully removed from @asset's proxy
* list.
*/
gboolean
ges_asset_unproxy (GESAsset * asset, GESAsset * proxy)
@ -873,10 +977,14 @@ ges_asset_unproxy (GESAsset * asset, GESAsset * proxy)
/**
* ges_asset_list_proxies:
* @asset: The #GESAsset to get proxies from
* @asset: A #GESAsset
*
* Returns: (element-type GESAsset) (transfer none): The list of proxies @asset has. Note that the default asset to be
* used is always the first in that list.
* Get all the proxies that the asset has. The first item of the list will
* be the default #GESAsset:proxy. The second will be the proxy that is
* 'next in line' to be default, and so on.
*
* Returns: (element-type GESAsset) (transfer none): The list of proxies
* that @asset has.
*/
GList *
ges_asset_list_proxies (GESAsset * asset)
@ -888,9 +996,11 @@ ges_asset_list_proxies (GESAsset * asset)
/**
* ges_asset_get_proxy:
* @asset: The #GESAsset to get currenlty used proxy
* @asset: A #GESAsset
*
* Returns: (transfer none) (nullable): The proxy in use for @asset
* Gets the default #GESAsset:proxy of the asset.
*
* Returns: (transfer none) (nullable): The default proxy of @asset.
*/
GESAsset *
ges_asset_get_proxy (GESAsset * asset)
@ -906,9 +1016,15 @@ ges_asset_get_proxy (GESAsset * asset)
/**
* ges_asset_get_proxy_target:
* @proxy: The #GESAsset from which to get the the asset it proxies.
* @proxy: A #GESAsset
*
* Returns: (transfer none) (nullable): The #GESAsset that is proxied by @proxy
* Gets the #GESAsset:proxy-target of the asset.
*
* Note that the proxy target may have loaded with an error, so you should
* call ges_asset_get_error() on the returned target.
*
* Returns: (transfer none) (nullable): The asset that @proxy is a proxy
* of.
*/
GESAsset *
ges_asset_get_proxy_target (GESAsset * proxy)
@ -993,9 +1109,9 @@ _ensure_asset_for_wrong_id (const gchar * wrong_id, GType extractable_type,
* ges_asset_get_extractable_type:
* @self: The #GESAsset
*
* Gets the type of object that can be extracted from @self
* Gets the #GESAsset:extractable-type of the asset.
*
* Returns: the type of object that can be extracted from @self
* Returns: The extractable type of @self.
*/
GType
ges_asset_get_extractable_type (GESAsset * self)
@ -1007,18 +1123,46 @@ ges_asset_get_extractable_type (GESAsset * self)
/**
* ges_asset_request:
* @extractable_type: The #GType of the object that can be extracted from the new asset.
* @id: (allow-none): The Identifier or %NULL
* @error: (allow-none): An error to be set in case something wrong happens or %NULL
* @extractable_type: The #GESAsset:extractable-type of the asset
* @id: (allow-none): The #GESAsset:id of the asset
* @error: (allow-none): An error to be set if the requested asset has
* loaded with an error, or %NULL to ignore
*
* Create a #GESAsset in the most simple cases, you should look at the @extractable_type
* documentation to see if that constructor can be called for this particular type
* Returns an asset with the given properties. If such an asset already
* exists in the cache (it has been previously created in GES), then a
* reference to the existing asset is returned. Otherwise, a newly created
* asset is returned, and also added to the cache.
*
* As it is recommanded not to instanciate assets for GESUriClip synchronously,
* it will not work with this method, but you can instead use the specific
* #ges_uri_clip_asset_request_sync method if you really want to.
* If the requested asset has been loaded with an error, then @error is
* set, if given, and %NULL will be returned instead.
*
* Returns: (transfer full) (allow-none): A reference to the wanted #GESAsset or %NULL
* Note that the given @id may not be exactly the #GESAsset:id that is
* set on the returned asset. For instance, it may be adjusted into a
* standard format. Or, if a #GESExtractable type does not have its
* extraction parametrised, as is the case by default, then the given @id
* may be ignored entirely and the #GESAsset:id set to some standard, in
* which case a %NULL @id can be given.
*
* Similarly, the given @extractable_type may not be exactly the
* #GESAsset:extractable-type that is set on the returned asset. Instead,
* the actual extractable type may correspond to a subclass of the given
* @extractable_type, depending on the given @id.
*
* Moreover, depending on the given @extractable_type, the returned asset
* may belong to a subclass of #GESAsset.
*
* Finally, if the requested asset has a #GESAsset:proxy, then the proxy
* that is found at the end of the chain of proxies is returned (a proxy's
* proxy will take its place, and so on, unless it has no proxy).
*
* Some asset subclasses only support asynchronous construction of its
* assets, such as #GESUriClip. For such assets this method will fail, and
* you should use ges_asset_request_async() instead. In the case of
* #GESUriClip, you can use ges_uri_clip_asset_request_sync() if you only
* want to wait for the request to finish.
*
* Returns: (transfer full) (allow-none): A reference to the requested
* asset, or %NULL if an error occurred.
*/
GESAsset *
ges_asset_request (GType extractable_type, const gchar * id, GError ** error)
@ -1091,6 +1235,8 @@ ges_asset_request (GType extractable_type, const gchar * id, GError ** error)
iface = g_type_interface_peek (klass, G_TYPE_INITABLE);
if (iface->init) {
/* FIXME: allow the error to be set, which GInitable is designed
* for! */
asset = g_initable_new (asset_type,
NULL, NULL, "id", real_id, "extractable-type",
extractable_type, NULL);
@ -1111,32 +1257,32 @@ done:
/**
* ges_asset_request_async:
* @extractable_type: The #GType of the object that can be extracted from the
* new asset. The class must implement the #GESExtractable interface.
* @id: The Identifier of the asset we want to create. This identifier depends of the extractable,
* type you want. By default it is the name of the class itself (or %NULL), but for example for a
* GESEffect, it will be the pipeline description, for a GESUriClip it
* will be the name of the file, etc... You should refer to the documentation of the #GESExtractable
* type you want to create a #GESAsset for.
* @cancellable: (allow-none): optional %GCancellable object, %NULL to ignore.
* @callback: a #GAsyncReadyCallback to call when the initialization is finished,
* Note that the @source of the callback will be the #GESAsset, but you need to
* make sure that the asset is properly loaded using the #ges_asset_request_finish
* method. This asset can not be used as is.
* @user_data: The user data to pass when @callback is called
* @extractable_type: The #GESAsset:extractable-type of the asset
* @id: (allow-none): The #GESAsset:id of the asset
* @cancellable: (allow-none): An object to allow cancellation of the
* asset request, or %NULL to ignore
* @callback: A function to call when the initialization is finished
* @user_data: Data to be passed to @callback
*
* The @callback will be called from a running #GMainLoop which is iterating a #GMainContext.
* Note that, users should ensure the #GMainContext, since this method will notify
* @callback from the thread which was associated with a thread default
* #GMainContext at calling ges_init().
* For example, if a user wants non-default #GMainContext to be associated
* with @callback, ges_init() must be called after g_main_context_push_thread_default ()
* with custom #GMainContext.
* Requests an asset with the given properties asynchronously (see
* ges_asset_request()). When the asset has been initialized or fetched
* from the cache, the given callback function will be called. The
* asset can then be retrieved in the callback using the
* ges_asset_request_finish() method on the given #GAsyncResult.
*
* Request a new #GESAsset asyncronously, @callback will be called when the materail is
* ready to be used or if an error occured.
* Note that the source object passed to the callback will be the
* #GESAsset corresponding to the request, but it may not have loaded
* correctly and therefore can not be used as is. Instead,
* ges_asset_request_finish() should be used to fetch a usable asset, or
* indicate that an error occurred in the asset's creation.
*
* Example of request of a GESAsset async:
* Note that the callback will be called in the #GMainLoop running under
* the same #GMainContext that ges_init() was called in. So, if you wish
* the callback to be invoked outside the default #GMainContext, you can
* call g_main_context_push_thread_default() in a new thread before
* calling ges_init().
*
* Example of an asynchronous asset request:
* |[
* // The request callback
* static void
@ -1255,21 +1401,23 @@ done:
/**
* ges_asset_needs_reload
* @extractable_type: The #GType of the object that can be extracted from the
* asset to be reloaded.
* @id: The identifier of the asset to mark as needing reload
* @extractable_type: The #GESAsset:extractable-type of the asset that
* needs reloading
* @id: (allow-none): The #GESAsset:id of the asset asset that needs
* reloading
*
* Sets an asset from the internal cache as needing reload. An asset needs reload
* in the case where, for example, we were missing a GstPlugin to use it and that
* plugin has been installed, or, that particular asset content as changed
* meanwhile (in the case of the usage of proxies).
* Indicate that an existing #GESAsset in the cache should be reloaded
* upon the next request. This can be used when some condition has
* changed, which may require that an existing asset should be updated.
* For example, if an external resource has changed or now become
* available.
*
* Once an asset has been set as "needs reload", requesting that asset again
* will lead to it being re discovered, and reloaded as if it was not in the
* cache before.
* Note, the asset is not immediately changed, but will only actually
* reload on the next call to ges_asset_request() or
* ges_asset_request_async().
*
* Returns: %TRUE if the asset was in the cache and could be set as needing reload,
* %FALSE otherwise.
* Returns: %TRUE if the specified asset exists in the cache and could be
* marked for reloading.
*/
gboolean
ges_asset_needs_reload (GType extractable_type, const gchar * id)
@ -1305,11 +1453,11 @@ ges_asset_needs_reload (GType extractable_type, const gchar * id)
/**
* ges_asset_get_id:
* @self: The #GESAsset to get ID from
* @self: A #GESAsset
*
* Gets the ID of a #GESAsset
* Gets the #GESAsset:id of the asset.
*
* Returns: The ID of @self
* Returns: The ID of @self.
*/
const gchar *
ges_asset_get_id (GESAsset * self)
@ -1321,15 +1469,16 @@ ges_asset_get_id (GESAsset * self)
/**
* ges_asset_extract:
* @self: The #GESAsset to get extract an object from
* @error: (allow-none): An error to be set in case something wrong happens or %NULL
* @self: The #GESAsset to extract an object from
* @error: (allow-none): An error to be set in case something goes wrong,
* or %NULL to ignore
*
* Extracts a new #GObject from @asset. The type of the object is
* defined by the extractable-type of @asset, you can check what
* type will be extracted from @asset using
* #ges_asset_get_extractable_type
* Extracts a new #GESAsset:extractable-type object from the asset. The
* #GESAsset:id of the asset may determine the properties and state of the
* newly created object.
*
* Returns: (transfer floating) (allow-none): A newly created #GESExtractable
* Returns: (transfer floating): A newly created object, or %NULL if an
* error occurred.
*/
GESExtractable *
ges_asset_extract (GESAsset * self, GError ** error)
@ -1354,13 +1503,15 @@ ges_asset_extract (GESAsset * self, GError ** error)
/**
* ges_asset_request_finish:
* @res: The #GAsyncResult from which to get the newly created #GESAsset
* @res: The task result to fetch the asset from
* @error: (out) (allow-none) (transfer full): An error to be set in case
* something wrong happens or %NULL
* something goes wrong, or %NULL to ignore
*
* Finalize the request of an async #GESAsset
* Fetches an asset requested by ges_asset_request_async(), which
* finalises the request.
*
* Returns: (transfer full)(allow-none): The #GESAsset previously requested
* Returns: (transfer full): The requested asset, or %NULL if an error
* occurred.
*/
GESAsset *
ges_asset_request_finish (GAsyncResult * res, GError ** error)
@ -1383,14 +1534,19 @@ ges_asset_request_finish (GAsyncResult * res, GError ** error)
/**
* ges_list_assets:
* @filter: Type of assets to list, `GES_TYPE_EXTRACTABLE` will list
* all assets
* @filter: The type of object that can be extracted from the asset
*
* List all @asset filtering per filter as defined by @filter.
* It copies the asset and thus will not be updated in time.
* List all the assets in the current cache whose
* #GESAsset:extractable-type are of the given type (including
* subclasses).
*
* Returns: (transfer container) (element-type GESAsset): The list of
* #GESAsset the object contains
* Note that, since only a #GESExtractable can be extracted from an asset,
* using `GES_TYPE_EXTRACTABLE` as @filter will return all the assets in
* the current cache.
*
* Returns: (transfer container) (element-type GESAsset): A list of all
* #GESAsset-s currently in the cache whose #GESAsset:extractable-type is
* of the @filter type.
*/
GList *
ges_list_assets (GType filter)
@ -1423,10 +1579,12 @@ ges_list_assets (GType filter)
/**
* ges_asset_get_error:
* @self: The asset to retrieve the error from
* @self: A #GESAsset
*
* Returns: (transfer none) (nullable): The #GError of the asset or %NULL if
* the asset was loaded without issue
* Retrieve the error that was set on the asset when it was loaded.
*
* Returns: (transfer none) (nullable): The error set on @asset, or
* %NULL if no error occurred when @asset was loaded.
*
* Since: 1.8
*/

28
ges/ges-asset.h
View file

@ -42,6 +42,14 @@ G_BEGIN_DECLS
#define GES_ASSET_GET_CLASS(obj) \
(G_TYPE_INSTANCE_GET_CLASS ((obj), GES_TYPE_ASSET, GESAssetClass))
/**
* GESAssetLoadingReturn:
* @GES_ASSET_LOADING_ERROR: Indicates that an error occurred
* @GES_ASSET_LOADING_ASYNC: Indicates that the loading is being performed
* asynchronously
* @GES_ASSET_LOADING_OK: Indicates that the loading is complete, without
* error
*/
typedef enum
{
GES_ASSET_LOADING_ERROR,
@ -65,6 +73,26 @@ struct _GESAsset
gpointer _ges_reserved[GES_PADDING];
};
/**
* GESAssetClass:
* @start_loading: A method to be called when an asset is being requested
* asynchronously. This will be after the properties of the asset have
* been set, so it is tasked with (re)loading the 'state' of the asset.
* The return value should indicated whether the loading is complete, is
* carrying on asynchronously, or an error occurred. The default
* implementation will simply return that loading is already complete (the
* asset is already in a usable state after the properties have been set).
* @extract: A method that returns a new object of the asset's
* #GESAsset:extractable-type, or %NULL if an error occurs. The default
* implementation will fetch the properties of the #GESExtractable from
* its get_parameters_from_id() class method and set them on a new
* #GESAsset:extractable-type #GObject, which is returned.
* @request_id_update: A method called by a #GESProject when an asset has
* failed to load. @error is the error given by
* ges_asset_request_finish (). Returns: %TRUE if a new id for @self was
* passed to @proposed_new_id.
*/
/* FIXME: add documentation for inform_proxy when it is used properly */
struct _GESAssetClass
{
GObjectClass parent;