#[repr(transparent)]pub struct Pad { /* private fields */ }
Expand description
A Element
is linked to other elements via “pads”, which are extremely
light-weight generic link points.
Pads have a PadDirection
, source pads produce data, sink pads consume
data.
Pads are typically created from a PadTemplate
with
from_template()
and are then added to a Element
. This usually
happens when the element is created but it can also happen dynamically based
on the data that the element is processing or based on the pads that the
application requests.
Pads without pad templates can be created with new()
,
which takes a direction and a name as an argument. If the name is None
,
then a guaranteed unique name will be assigned to it.
A Element
creating a pad will typically use the various
gst_pad_set_*_function() calls to register callbacks for events, queries or
dataflow on the pads.
gst_pad_get_parent()
will retrieve the Element
that owns the pad.
After two pads are retrieved from an element by ElementExt::static_pad()
,
the pads can be linked with PadExt::link()
. (For quick links,
you can also use ElementExt::link()
, which will make the obvious
link for you if it’s straightforward.). Pads can be unlinked again with
PadExt::unlink()
. PadExt::peer()
can be used to check what the pad is
linked to.
Before dataflow is possible on the pads, they need to be activated with
PadExt::set_active()
.
PadExtManual::query()
and PadExtManual::peer_query()
can be used to query various
properties of the pad and the stream.
To send a Event
on a pad, use PadExtManual::send_event()
and
PadExtManual::push_event()
. Some events will be sticky on the pad, meaning that
after they pass on the pad they can be queried later with
PadExtManual::sticky_event()
and PadExtManual::sticky_events_foreach()
.
PadExt::current_caps()
and PadExt::has_current_caps()
are convenience
functions to query the current sticky CAPS event on a pad.
GstElements will use PadExtManual::push()
and PadExtManual::pull_range()
to push out
or pull in a buffer.
The dataflow, events and queries that happen on a pad can be monitored with
probes that can be installed with PadExtManual::add_probe()
. PadExt::is_blocked()
can be used to check if a block probe is installed on the pad.
PadExt::is_blocking()
checks if the blocking probe is currently blocking the
pad. PadExtManual::remove_probe()
is used to remove a previously installed probe
and unblock blocking probes if any.
Pad have an offset that can be retrieved with PadExt::offset()
. This
offset will be applied to the running_time of all data passing over the pad.
PadExt::set_offset()
can be used to change the offset.
Convenience functions exist to start, pause and stop the task on a pad with
PadExtManual::start_task()
, PadExt::pause_task()
and PadExt::stop_task()
respectively.
Implements
Implementations
pub fn builder_with_static_template(
templ: &StaticPadTemplate,
name: Option<&str>
) -> PadBuilder<Self>
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
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
.