Struct gstreamer_editing_services::Asset
source · [−]#[repr(transparent)]pub struct Asset { /* private fields */ }
Expand description
A Asset
in the GStreamer Editing Services represents a resources
that can be used. In particular, any class that implements the
Extractable
interface may have some associated assets with a
corresponding property::Asset::extractable-type
, from which its objects can be
extracted using AssetExt::extract()
. Some examples would be
Clip
, Formatter
and TrackElement
.
All assets that are created within GES are stored in a cache; one per
each property::Asset::id
and property::Asset::extractable-type
pair. These assets can
be fetched, and initialized if they do not yet exist in the cache,
using request()
.
⚠️ The following code is in c ⚠️
GESAsset *effect_asset;
GESEffect *effect;
// You create an asset for an effect
effect_asset = ges_asset_request (GES_TYPE_EFFECT, "agingtv", NULL);
// And now you can extract an instance of GESEffect from that asset
effect = GES_EFFECT (ges_asset_extract (effect_asset));
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 TransitionClip
and
Formatter
, which you can use to list all the available transition
types and supported formats.
The other advantage is that Asset
implements MetaContainer
, so
metadata can be set on the asset, with some subclasses automatically
creating this metadata on initiation.
For example, to display information about the supported formats, you could do the following:
GList *formatter_assets, *tmp;
// List all the transitions
formatter_assets = ges_list_assets (GES_TYPE_FORMATTER);
// Print some infos about the formatter GESAsset
for (tmp = formatter_assets; tmp; tmp = tmp->next) {
gst_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));
}
g_list_free (transition_assets);
ID
Each asset is uniquely defined in the cache by its
property::Asset::extractable-type
and property::Asset::id
. Depending on the
property::Asset::extractable-type
, the property::Asset::id
can be used to parametrise
the creation of the object upon extraction. By default, a class that
implements Extractable
will only have a single associated asset,
with an property::Asset::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 TransitionClip
the
property::Asset::id
will be a nickname of the property::TransitionClip::vtype
. You
should check the documentation for each extractable type to see if they
differ from the default.
Moreover, each property::Asset::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 Project
to easily manage the assets of a
Timeline
.
Proxies
Some assets can (temporarily) act as the property::Asset::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 UriClipAsset
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 AssetExt::set_proxy()
, and you can remove
them with AssetExt::unproxy()
.
Implements
Implementations
Indicate that an existing Asset
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.
Note, the asset is not immediately changed, but will only actually
reload on the next call to request()
or
request_async()
.
extractable_type
The property::Asset::extractable-type
of the asset that
needs reloading
id
The property::Asset::id
of the asset asset that needs
reloading
Returns
true
if the specified asset exists in the cache and could be
marked for reloading.
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.
If the requested asset has been loaded with an error, then error
is
set, if given, and None
will be returned instead.
Note that the given id
may not be exactly the property::Asset::id
that is
set on the returned asset. For instance, it may be adjusted into a
standard format. Or, if a Extractable
type does not have its
extraction parametrised, as is the case by default, then the given id
may be ignored entirely and the property::Asset::id
set to some standard, in
which case a None
id
can be given.
Similarly, the given extractable_type
may not be exactly the
property::Asset::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 Asset
.
Finally, if the requested asset has a property::Asset::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 UriClip
. For such assets this method will fail, and
you should use request_async()
instead. In the case of
UriClip
, you can use UriClipAsset::request_sync()
if you only
want to wait for the request to finish.
extractable_type
The property::Asset::extractable-type
of the asset
id
The property::Asset::id
of the asset
Returns
A reference to the requested
asset, or None
if an error occurred.
Requests an asset with the given properties asynchronously (see
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
.
Note that the source object passed to the callback will be the
Asset
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.
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 following code is in c ⚠️
// The request callback
static void
asset_loaded_cb (GESAsset * source, GAsyncResult * res, gpointer user_data)
{
GESAsset *asset;
GError *error = NULL;
asset = ges_asset_request_finish (res, &error);
if (asset) {
gst_print ("The file: %s is usable as a GESUriClip",
ges_asset_get_id (asset));
} else {
gst_print ("The file: %s is *not* usable as a GESUriClip because: %s",
ges_asset_get_id (source), error->message);
}
gst_object_unref (asset);
}
// The request:
ges_asset_request_async (GES_TYPE_URI_CLIP, some_uri, NULL,
(GAsyncReadyCallback) asset_loaded_cb, user_data);
extractable_type
The property::Asset::extractable-type
of the asset
id
The property::Asset::id
of the asset
cancellable
An object to allow cancellation of the
asset request, or None
to ignore
callback
A function to call when the initialization is finished
Trait Implementations
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
Returns the type identifier of Self
.
Auto Trait Implementations
impl RefUnwindSafe for Asset
impl UnwindSafe for Asset
Blanket Implementations
Mutably borrows from an owned value. Read more
Upcasts an object to a superclass or interface T
. Read more
Upcasts an object to a reference of its superclass or interface T
. Read more
Tries to downcast to a subclass or interface implementor T
. Read more
Tries to downcast to a reference of its subclass or interface implementor T
. Read more
Tries to cast to an object of type T
. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast
and upcast
will do many checks at compile-time already. Read more
Tries to cast to reference to an object of type T
. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast
and upcast
will do many checks at compile-time already. Read more
Casts to T
unconditionally. Read more
Casts to &T
unconditionally. Read more
pub fn parent_class_init<T>(class: &mut Class<U>) where
T: ObjectSubclass,
<U as ParentClassIs>::Parent: IsSubclassable<T>,
pub fn parent_instance_init<T>(instance: &mut InitializingObject<T>) where
T: ObjectSubclass,
<U as ParentClassIs>::Parent: IsSubclassable<T>,
Returns true
if the object is an instance of (can be cast to) T
.
Returns the ObjectClass
of the object. Read more
Returns the class of the object in the given type T
. Read more
Returns the interface T
of the object. Read more
Similar to Self::set_property
but fails instead of panicking.
Sets the property property_name
of the object to value value
. Read more
Similar to Self::set_property
but fails instead of panicking.
Sets the property property_name
of the object to value value
. Read more
Similar to Self::set_properties
but fails instead of panicking.
Sets multiple properties of the object at once. Read more
Similar to Self::set_properties_from_value
but fails instead of panicking.
Sets multiple properties of the object at once. Read more
Similar to Self::property
but fails instead of panicking.
Gets the property property_name
of the object and cast it to the type V. Read more
Similar to Self::property_value
but fails instead of panicking.
Gets the property property_name
of the object. Read more
Check if the object has a property property_name
of the given type_
. Read more
Get the type of the property property_name
of this object. Read more
Get the ParamSpec
of the property property_name
of this object.
Return all ParamSpec
of the properties of this object.
Freeze all property notifications until the return guard object is dropped. Read more
Set arbitrary data on this object with the given key
. Read more
Return previously set arbitrary data of this object with the given key
. Read more
Retrieve previously set arbitrary data of this object with the given key
. Read more
Set arbitrary data on this object with the given key
. Read more
Return previously set arbitrary data of this object with the given key
. Read more
Retrieve previously set arbitrary data of this object with the given key
. Read more
Block a given signal handler. Read more
Unblock a given signal handler.
Stop emission of the currently emitted signal.
Stop emission of the currently emitted signal by the (possibly detailed) signal name.
Similar to Self::connect
but fails instead of panicking.
Connect to the signal signal_name
on this object. Read more
Similar to Self::connect_id
but fails instead of panicking.
Connect to the signal signal_id
on this object. Read more
Similar to Self::connect_local
but fails instead of panicking.
Connect to the signal signal_name
on this object. Read more
Similar to Self::connect_local_id
but fails instead of panicking.
Connect to the signal signal_id
on this object. Read more
Similar to Self::connect_unsafe
but fails instead of panicking.
Connect to the signal signal_name
on this object. Read more
Similar to Self::connect_unsafe_id
but fails instead of panicking.
pub fn try_connect_closure(
&self,
signal_name: &str,
after: bool,
closure: RustClosure
) -> Result<SignalHandlerId, BoolError>
pub fn try_connect_closure(
&self,
signal_name: &str,
after: bool,
closure: RustClosure
) -> Result<SignalHandlerId, BoolError>
Similar to Self::connect_closure
but fails instead of panicking.
pub fn connect_closure(
&self,
signal_name: &str,
after: bool,
closure: RustClosure
) -> SignalHandlerId
pub fn connect_closure(
&self,
signal_name: &str,
after: bool,
closure: RustClosure
) -> SignalHandlerId
Connect a closure to the signal signal_name
on this object. Read more
pub fn try_connect_closure_id(
&self,
signal_id: SignalId,
details: Option<Quark>,
after: bool,
closure: RustClosure
) -> Result<SignalHandlerId, BoolError>
pub fn try_connect_closure_id(
&self,
signal_id: SignalId,
details: Option<Quark>,
after: bool,
closure: RustClosure
) -> Result<SignalHandlerId, BoolError>
Similar to Self::connect_closure_id
but fails instead of panicking.
pub fn connect_closure_id(
&self,
signal_id: SignalId,
details: Option<Quark>,
after: bool,
closure: RustClosure
) -> SignalHandlerId
pub fn connect_closure_id(
&self,
signal_id: SignalId,
details: Option<Quark>,
after: bool,
closure: RustClosure
) -> SignalHandlerId
Connect a closure to the signal signal_id
on this object. Read more
Limits the lifetime of closure
to the lifetime of the object. When
the object’s reference count drops to zero, the closure will be
invalidated. An invalidated closure will ignore any calls to
Closure::invoke
. Read more
Connect to the signal signal_id
on this object. Read more
Similar to Self::emit
but fails instead of panicking.
Emit signal by signal id. Read more
Similar to Self::emit_with_values
but fails instead of panicking.
Same as Self::emit
but takes Value
for the arguments.
pub fn try_emit_by_name<R>(
&self,
signal_name: &str,
args: &[&dyn ToValue]
) -> Result<R, BoolError> where
R: TryFromClosureReturnValue,
pub fn try_emit_by_name<R>(
&self,
signal_name: &str,
args: &[&dyn ToValue]
) -> Result<R, BoolError> where
R: TryFromClosureReturnValue,
Similar to Self::emit_by_name
but fails instead of panicking.
pub fn emit_by_name<R>(&self, signal_name: &str, args: &[&dyn ToValue]) -> R where
R: TryFromClosureReturnValue,
pub fn emit_by_name<R>(&self, signal_name: &str, args: &[&dyn ToValue]) -> R where
R: TryFromClosureReturnValue,
Emit signal by its name. Read more
Similar to Self::emit_by_name_with_values
but fails instead of panicking.
Emit signal by its name. Read more
pub fn try_emit_with_details<R>(
&self,
signal_id: SignalId,
details: Quark,
args: &[&dyn ToValue]
) -> Result<R, BoolError> where
R: TryFromClosureReturnValue,
pub fn try_emit_with_details<R>(
&self,
signal_id: SignalId,
details: Quark,
args: &[&dyn ToValue]
) -> Result<R, BoolError> where
R: TryFromClosureReturnValue,
Similar to Self::emit_with_details
but fails instead of panicking.
pub fn emit_with_details<R>(
&self,
signal_id: SignalId,
details: Quark,
args: &[&dyn ToValue]
) -> R where
R: TryFromClosureReturnValue,
pub fn emit_with_details<R>(
&self,
signal_id: SignalId,
details: Quark,
args: &[&dyn ToValue]
) -> R where
R: TryFromClosureReturnValue,
Emit signal by signal id with details. Read more
Similar to Self::emit_with_details_and_values
but fails instead of panicking.
Emit signal by signal id with details. Read more
Disconnect a previously connected signal handler.
pub fn connect_notify<F>(&self, name: Option<&str>, f: F) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec) + Send + Sync,
pub fn connect_notify<F>(&self, name: Option<&str>, f: F) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec) + Send + Sync,
Connect to the notify
signal of the object. Read more
pub fn connect_notify_local<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec),
pub fn connect_notify_local<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec),
Connect to the notify
signal of the object. Read more
pub unsafe fn connect_notify_unsafe<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: Fn(&T, &ParamSpec),
pub unsafe fn connect_notify_unsafe<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: Fn(&T, &ParamSpec),
Connect to the notify
signal of the object. Read more
Notify that the given property has changed its value. Read more
Notify that the given property has changed its value. Read more
pub fn bind_property<O>(
&'a self,
source_property: &'a str,
target: &'a O,
target_property: &'a str
) -> BindingBuilder<'a> where
O: ObjectType,
pub fn bind_property<O>(
&'a self,
source_property: &'a str,
target: &'a O,
target_property: &'a str
) -> BindingBuilder<'a> where
O: ObjectType,
Bind property source_property
on this object to the target_property
on the target
object. Read more
Ensures that the type has been registered with the type system.
Returns a SendValue
clone of self
.