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A #GstElement is linked to other elements via "pads", which are extremely light-weight generic link points.

Pads have a #GstPadDirection, source pads produce data, sink pads consume data.

Pads are typically created from a #GstPadTemplate with gst_pad_new_from_template() and are then added to a #GstElement. 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 gst_pad_new(), which takes a direction and a name as an argument. If the name is %NULL, then a guaranteed unique name will be assigned to it.

A #GstElement 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 #GstElement that owns the pad.

After two pads are retrieved from an element by gst_element_get_static_pad(), the pads can be linked with gst_pad_link(). (For quick links, you can also use gst_element_link(), which will make the obvious link for you if it's straightforward.). Pads can be unlinked again with gst_pad_unlink(). gst_pad_get_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 gst_pad_set_active().

gst_pad_query() and gst_pad_peer_query() can be used to query various properties of the pad and the stream.

To send a #GstEvent on a pad, use gst_pad_send_event() and gst_pad_push_event(). Some events will be sticky on the pad, meaning that after they pass on the pad they can be queried later with gst_pad_get_sticky_event() and gst_pad_sticky_events_foreach(). gst_pad_get_current_caps() and gst_pad_has_current_caps() are convenience functions to query the current sticky CAPS event on a pad.

GstElements will use gst_pad_push() and gst_pad_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 gst_pad_add_probe(). gst_pad_is_blocked() can be used to check if a block probe is installed on the pad. gst_pad_is_blocking() checks if the blocking probe is currently blocking the pad. gst_pad_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 gst_pad_get_offset(). This offset will be applied to the running_time of all data passing over the pad. gst_pad_set_offset() can be used to change the offset.

Convenience functions exist to start, pause and stop the task on a pad with gst_pad_start_task(), gst_pad_pause_task() and gst_pad_stop_task() respectively.

Hierarchy

Index

Constructors

Properties

Methods

Constructors

Properties

caps: Gst.Caps
direction: Gst.PadDirection

the direction of the pad, cannot change after creating the pad.

field
element_private: object

private data owned by the parent element

field
flags: number

flags for this object

field
g_type_instance: TypeInstance
name: string

The name of the object

field
object: Gst.Object
offset: number

The offset that will be applied to the running time of the pad.

padtemplate: Gst.PadTemplate

padtemplate for this pad

field
parent: Gst.Object

this object's parent, weak ref

field
template: Gst.PadTemplate
$gtype: GType<Gst.Pad>
name: string

Methods

  • activate_mode(mode: PadMode, active: boolean): boolean
  • Activates or deactivates the given pad in mode via dispatching to the pad's activatemodefunc. For use from within pad activation functions only.

    If you don't know what this is, you probably don't want to call it.

    Parameters

    • mode: PadMode

      the requested activation mode

    • active: boolean

      whether or not the pad should be active.

    Returns boolean

  • Attach the #GstControlBinding to the object. If there already was a #GstControlBinding for this property it will be replaced.

    The object's reference count will be incremented, and any floating reference will be removed (see gst_object_ref_sink())

    Parameters

    Returns boolean

  • Be notified of different states of pads. The provided callback is called for every state that matches mask.

    Probes are called in groups: First GST_PAD_PROBE_TYPE_BLOCK probes are called, then others, then finally GST_PAD_PROBE_TYPE_IDLE. The only exception here are GST_PAD_PROBE_TYPE_IDLE probes that are called immediately if the pad is already idle while calling gst_pad_add_probe(). In each of the groups, probes are called in the order in which they were added.

    Parameters

    Returns number

  • Creates a binding between source_property on source and target_property on target.

    Whenever the source_property is changed the target_property is updated using the same value. For instance:

      g_object_bind_property (action, "active", widget, "sensitive", 0);
    

    Will result in the "sensitive" property of the widget #GObject instance to be updated with the same value of the "active" property of the action #GObject instance.

    If flags contains %G_BINDING_BIDIRECTIONAL then the binding will be mutual: if target_property on target changes then the source_property on source will be updated as well.

    The binding will automatically be removed when either the source or the target instances are finalized. To remove the binding without affecting the source and the target you can just call g_object_unref() on the returned #GBinding instance.

    Removing the binding by calling g_object_unref() on it must only be done if the binding, source and target are only used from a single thread and it is clear that both source and target outlive the binding. Especially it is not safe to rely on this if the binding, source or target can be finalized from different threads. Keep another reference to the binding and use g_binding_unbind() instead to be on the safe side.

    A #GObject can have multiple bindings.

    Parameters

    • source_property: string

      the property on source to bind

    • target: GObject.Object

      the target #GObject

    • target_property: string

      the property on target to bind

    • flags: BindingFlags

      flags to pass to #GBinding

    Returns Binding

  • Creates a binding between source_property on source and target_property on target, allowing you to set the transformation functions to be used by the binding.

    This function is the language bindings friendly version of g_object_bind_property_full(), using #GClosures instead of function pointers.

    Parameters

    • source_property: string

      the property on source to bind

    • target: GObject.Object

      the target #GObject

    • target_property: string

      the property on target to bind

    • flags: BindingFlags

      flags to pass to #GBinding

    • transform_to: TClosure<any, any>

      a #GClosure wrapping the transformation function from the source to the target, or %NULL to use the default

    • transform_from: TClosure<any, any>

      a #GClosure wrapping the transformation function from the target to the source, or %NULL to use the default

    Returns Binding

  • can_link(sinkpad: Gst.Pad): boolean
  • Checks if the source pad and the sink pad are compatible so they can be linked.

    Parameters

    • sinkpad: Gst.Pad

      the sink #GstPad.

    Returns boolean

  • Chain a buffer to pad.

    The function returns #GST_FLOW_FLUSHING if the pad was flushing.

    If the buffer type is not acceptable for pad (as negotiated with a preceding GST_EVENT_CAPS event), this function returns #GST_FLOW_NOT_NEGOTIATED.

    The function proceeds calling the chain function installed on pad (see gst_pad_set_chain_function()) and the return value of that function is returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if pad has no chain function.

    In all cases, success or failure, the caller loses its reference to buffer after calling this function.

    Parameters

    • buffer: Gst.Buffer

      the #GstBuffer to send, return GST_FLOW_ERROR if not.

    Returns Gst.FlowReturn

  • Chain a bufferlist to pad.

    The function returns #GST_FLOW_FLUSHING if the pad was flushing.

    If pad was not negotiated properly with a CAPS event, this function returns #GST_FLOW_NOT_NEGOTIATED.

    The function proceeds calling the chainlist function installed on pad (see gst_pad_set_chain_list_function()) and the return value of that function is returned to the caller. #GST_FLOW_NOT_SUPPORTED is returned if pad has no chainlist function.

    In all cases, success or failure, the caller loses its reference to list after calling this function.

    MT safe.

    Parameters

    • list: Gst.BufferList

      the #GstBufferList to send, return GST_FLOW_ERROR if not.

    Returns Gst.FlowReturn

  • check_reconfigure(): boolean
  • Check and clear the #GST_PAD_FLAG_NEED_RECONFIGURE flag on pad and return %TRUE if the flag was set.

    Returns boolean

  • connect(sigName: "linked", callback: Gst.Pad_LinkedSignalCallback): number
  • connect(sigName: "unlinked", callback: Gst.Pad_UnlinkedSignalCallback): number
  • connect(sigName: "notify::caps", callback: (($obj: Gst.Pad, pspec: ParamSpec) => void)): number
  • connect(sigName: "notify::offset", callback: (($obj: Gst.Pad, pspec: ParamSpec) => void)): number
  • connect(sigName: "notify::template", callback: (($obj: Gst.Pad, pspec: ParamSpec) => void)): number
  • connect(sigName: string, callback: ((...args: any[]) => void)): number
  • connect_after(sigName: "linked", callback: Gst.Pad_LinkedSignalCallback): number
  • connect_after(sigName: "unlinked", callback: Gst.Pad_UnlinkedSignalCallback): number
  • connect_after(sigName: "notify::caps", callback: (($obj: Gst.Pad, pspec: ParamSpec) => void)): number
  • connect_after(sigName: "notify::offset", callback: (($obj: Gst.Pad, pspec: ParamSpec) => void)): number
  • connect_after(sigName: "notify::template", callback: (($obj: Gst.Pad, pspec: ParamSpec) => void)): number
  • connect_after(sigName: string, callback: ((...args: any[]) => void)): number
  • create_stream_id(parent: Gst.Element, stream_id: string): string
  • Creates a stream-id for the source #GstPad pad by combining the upstream information with the optional stream_id of the stream of pad. pad must have a parent #GstElement and which must have zero or one sinkpad. stream_id can only be %NULL if the parent element of pad has only a single source pad.

    This function generates an unique stream-id by getting the upstream stream-start event stream ID and appending stream_id to it. If the element has no sinkpad it will generate an upstream stream-id by doing an URI query on the element and in the worst case just uses a random number. Source elements that don't implement the URI handler interface should ideally generate a unique, deterministic stream-id manually instead.

    Since stream IDs are sorted alphabetically, any numbers in the stream ID should be printed with a fixed number of characters, preceded by 0's, such as by using the format %03u instead of %u.

    Parameters

    • parent: Gst.Element

      Parent #GstElement of pad

    • stream_id: string

      The stream-id

    Returns string

  • default_error(error: GLib.Error, debug: string): void
  • A default error function that uses g_printerr() to display the error message and the optional debug string..

    The default handler will simply print the error string using g_print.

    Parameters

    • error: GLib.Error

      the GError.

    • debug: string

      an additional debug information string, or %NULL

    Returns void

  • disconnect(id: number): void
  • emit(sigName: "linked", peer: Gst.Pad, ...args: any[]): void
  • emit(sigName: "unlinked", peer: Gst.Pad, ...args: any[]): void
  • emit(sigName: "notify::caps", ...args: any[]): void
  • emit(sigName: "notify::offset", ...args: any[]): void
  • emit(sigName: "notify::template", ...args: any[]): void
  • emit(sigName: string, ...args: any[]): void
  • Invokes the default event handler for the given pad.

    The EOS event will pause the task associated with pad before it is forwarded to all internally linked pads,

    The event is sent to all pads internally linked to pad. This function takes ownership of event.

    Parameters

    • parent: Gst.Object

      the parent of pad or %NULL

    • event: Gst.Event

      the #GstEvent to handle.

    Returns boolean

  • force_floating(): void
  • This function is intended for #GObject implementations to re-enforce a [floating][floating-ref] object reference. Doing this is seldom required: all #GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling g_object_ref_sink().

    Returns void

  • Calls forward for all internally linked pads of pad. This function deals with dynamically changing internal pads and will make sure that the forward function is only called once for each pad.

    When forward returns %TRUE, no further pads will be processed.

    Parameters

    Returns boolean

  • freeze_notify(): void
  • Increases the freeze count on object. If the freeze count is non-zero, the emission of "notify" signals on object is stopped. The signals are queued until the freeze count is decreased to zero. Duplicate notifications are squashed so that at most one #GObject::notify signal is emitted for each property modified while the object is frozen.

    This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.

    Returns void

  • Gets the capabilities of the allowed media types that can flow through pad and its peer.

    The allowed capabilities is calculated as the intersection of the results of calling gst_pad_query_caps() on pad and its peer. The caller owns a reference on the resulting caps.

    Returns Gst.Caps

  • get_control_rate(): number
  • Obtain the control-rate for this object. Audio processing #GstElement objects will use this rate to sub-divide their processing loop and call gst_object_sync_values() in between. The length of the processing segment should be up to control-rate nanoseconds.

    If the object is not under property control, this will return %GST_CLOCK_TIME_NONE. This allows the element to avoid the sub-dividing.

    The control-rate is not expected to change if the element is in %GST_STATE_PAUSED or %GST_STATE_PLAYING.

    Returns number

  • get_data(key?: string): object
  • Gets a named field from the objects table of associations (see g_object_set_data()).

    Parameters

    • Optional key: string

      name of the key for that association

    Returns object

  • get_element_private(): object
  • get_g_value_array(property_name: string, timestamp?: number, interval?: number, values?: any[]): boolean
  • Gets a number of #GValues for the given controlled property starting at the requested time. The array values need to hold enough space for n_values of #GValue.

    This function is useful if one wants to e.g. draw a graph of the control curve or apply a control curve sample by sample.

    Parameters

    • property_name: string

      the name of the property to get

    • Optional timestamp: number

      the time that should be processed

    • Optional interval: number

      the time spacing between subsequent values

    • Optional values: any[]

      array to put control-values in

    Returns boolean

  • get_name(): string
  • Returns a copy of the name of object. Caller should g_free() the return value after usage. For a nameless object, this returns %NULL, which you can safely g_free() as well.

    Free-function: g_free

    Returns string

  • get_offset(): number
  • get_path_string(): string
  • get_property(property_name?: string, value?: any): void
  • Gets a property of an object.

    The value can be:

    • an empty #GValue initialized by %G_VALUE_INIT, which will be automatically initialized with the expected type of the property (since GLib 2.60)
    • a #GValue initialized with the expected type of the property
    • a #GValue initialized with a type to which the expected type of the property can be transformed

    In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling g_value_unset().

    Note that g_object_get_property() is really intended for language bindings, g_object_get() is much more convenient for C programming.

    Parameters

    • Optional property_name: string

      the name of the property to get

    • Optional value: any

      return location for the property value

    Returns void

  • get_qdata(quark: number): object
  • When pad is flushing this function returns #GST_FLOW_FLUSHING immediately and buffer is %NULL.

    Calls the getrange function of pad, see #GstPadGetRangeFunction for a description of a getrange function. If pad has no getrange function installed (see gst_pad_set_getrange_function()) this function returns #GST_FLOW_NOT_SUPPORTED.

    If buffer points to a variable holding %NULL, a valid new #GstBuffer will be placed in buffer when this function returns #GST_FLOW_OK. The new buffer must be freed with gst_buffer_unref() after usage.

    When buffer points to a variable that points to a valid #GstBuffer, the buffer will be filled with the result data when this function returns #GST_FLOW_OK. If the provided buffer is larger than size, only size bytes will be filled in the result buffer and its size will be updated accordingly.

    Note that less than size bytes can be returned in buffer when, for example, an EOS condition is near or when buffer is not large enough to hold size bytes. The caller should check the result buffer size to get the result size.

    When this function returns any other result value than #GST_FLOW_OK, buffer will be unchanged.

    This is a lowlevel function. Usually gst_pad_pull_range() is used.

    Parameters

    • offset: number

      The start offset of the buffer

    • size: number

      The length of the buffer

    Returns [Gst.FlowReturn, Gst.Buffer]

  • get_single_internal_link(): Gst.Pad
  • Returns a new reference of the sticky event of type event_type from the event.

    Parameters

    • event_type: Gst.EventType

      the #GstEventType that should be retrieved.

    • idx: number

      the index of the event

    Returns Gst.Event

  • Returns the current #GstStream for the pad, or %NULL if none has been set yet, i.e. the pad has not received a stream-start event yet.

    This is a convenience wrapper around gst_pad_get_sticky_event() and gst_event_parse_stream().

    Returns Gst.Stream

  • get_stream_id(): string
  • Returns the current stream-id for the pad, or %NULL if none has been set yet, i.e. the pad has not received a stream-start event yet.

    This is a convenience wrapper around gst_pad_get_sticky_event() and gst_event_parse_stream_start().

    The returned stream-id string should be treated as an opaque string, its contents should not be interpreted.

    Returns string

  • get_value(property_name: string, timestamp?: number): any
  • Gets the value for the given controlled property at the requested time.

    Parameters

    • property_name: string

      the name of the property to get

    • Optional timestamp: number

      the time the control-change should be read from

    Returns any

  • getv(names: string[], values: any[]): void
  • Gets n_properties properties for an object. Obtained properties will be set to values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.

    Parameters

    • names: string[]

      the names of each property to get

    • values: any[]

      the values of each property to get

    Returns void

  • has_active_control_bindings(): boolean
  • Check if object has an ancestor ancestor somewhere up in the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.

    Parameters

    • ancestor: Gst.Object

      a #GstObject to check as ancestor

    Returns boolean

  • has_as_ancestor(ancestor: Gst.Object): boolean
  • has_current_caps(): boolean
  • is_active(): boolean
  • is_blocked(): boolean
  • Checks if the pad is blocked or not. This function returns the last requested state of the pad. It is not certain that the pad is actually blocking at this point (see gst_pad_is_blocking()).

    Returns boolean

  • is_blocking(): boolean
  • Checks if the pad is blocking or not. This is a guaranteed state of whether the pad is actually blocking on a #GstBuffer or a #GstEvent.

    Returns boolean

  • is_floating(): boolean
  • is_linked(): boolean
  • Gets an iterator for the pads to which the given pad is linked to inside of the parent element.

    Each #GstPad element yielded by the iterator will have its refcount increased, so unref after use.

    Free-function: gst_iterator_free

    Returns Gst.Iterator

  • Iterate the list of pads to which the given pad is linked to inside of the parent element. This is the default handler, and thus returns an iterator of all of the pads inside the parent element with opposite direction.

    The caller must free this iterator after use with gst_iterator_free().

    Parameters

    • parent: Gst.Object

      the parent of pad or %NULL

    Returns Gst.Iterator

  • Links the source pad and the sink pad.

    This variant of #gst_pad_link provides a more granular control on the checks being done when linking. While providing some considerable speedups the caller of this method must be aware that wrong usage of those flags can cause severe issues. Refer to the documentation of #GstPadLinkCheck for more information.

    MT Safe.

    Parameters

    Returns Gst.PadLinkReturn

  • link_maybe_ghosting(sink: Gst.Pad): boolean
  • Links src to sink, creating any #GstGhostPad's in between as necessary.

    This is a convenience function to save having to create and add intermediate #GstGhostPad's as required for linking across #GstBin boundaries.

    If src or sink pads don't have parent elements or do not share a common ancestor, the link will fail.

    Parameters

    Returns boolean

  • Links src to sink, creating any #GstGhostPad's in between as necessary.

    This is a convenience function to save having to create and add intermediate #GstGhostPad's as required for linking across #GstBin boundaries.

    If src or sink pads don't have parent elements or do not share a common ancestor, the link will fail.

    Calling gst_pad_link_maybe_ghosting_full() with flags == %GST_PAD_LINK_CHECK_DEFAULT is the recommended way of linking pads with safety checks applied.

    Parameters

    Returns boolean

  • mark_reconfigure(): void
  • Mark a pad for needing reconfiguration. The next call to gst_pad_check_reconfigure() will return %TRUE after this call.

    Returns void

  • needs_reconfigure(): boolean
  • Check the #GST_PAD_FLAG_NEED_RECONFIGURE flag on pad and return %TRUE if the flag was set.

    Returns boolean

  • notify(property_name: string): void
  • Emits a "notify" signal for the property property_name on object.

    When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.

    Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.

    Parameters

    • property_name: string

      the name of a property installed on the class of object.

    Returns void

  • Emits a "notify" signal for the property specified by pspec on object.

    This function omits the property name lookup, hence it is faster than g_object_notify().

    One way to avoid using g_object_notify() from within the class that registered the properties, and using g_object_notify_by_pspec() instead, is to store the GParamSpec used with g_object_class_install_property() inside a static array, e.g.:

      enum
    {
    PROP_0,
    PROP_FOO,
    PROP_LAST
    };

    static GParamSpec *properties[PROP_LAST];

    static void
    my_object_class_init (MyObjectClass *klass)
    {
    properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
    0, 100,
    50,
    G_PARAM_READWRITE);
    g_object_class_install_property (gobject_class,
    PROP_FOO,
    properties[PROP_FOO]);
    }

    and then notify a change on the "foo" property with:

      g_object_notify_by_pspec (self, properties[PROP_FOO]);
    

    Parameters

    • pspec: ParamSpec

      the #GParamSpec of a property installed on the class of object.

    Returns void

  • pause_task(): boolean
  • Pause the task of pad. This function will also wait until the function executed by the task is finished if this function is not called from the task function.

    Returns boolean

  • Performs gst_pad_query() on the peer of pad.

    The caller is responsible for both the allocation and deallocation of the query structure.

    Parameters

    • query: Gst.Query

      the #GstQuery to perform.

    Returns boolean

  • peer_query_accept_caps(caps: Gst.Caps): boolean
  • Check if the peer of pad accepts caps. If pad has no peer, this function returns %TRUE.

    Parameters

    • caps: Gst.Caps

      a #GstCaps to check on the pad

    Returns boolean

  • Gets the capabilities of the peer connected to this pad. Similar to gst_pad_query_caps().

    When called on srcpads filter contains the caps that upstream could produce in the order preferred by upstream. When called on sinkpads filter contains the caps accepted by downstream in the preferred order. filter might be %NULL but if it is not %NULL the returned caps will be a subset of filter.

    Parameters

    • filter: Gst.Caps

      a #GstCaps filter, or %NULL.

    Returns Gst.Caps

  • peer_query_convert(src_format: Gst.Format, src_val: number, dest_format: Gst.Format): [boolean, number]
  • Queries the peer pad of a given sink pad to convert src_val in src_format to dest_format.

    Parameters

    • src_format: Gst.Format

      a #GstFormat to convert from.

    • src_val: number

      a value to convert.

    • dest_format: Gst.Format

      the #GstFormat to convert to.

    Returns [boolean, number]

  • peer_query_duration(format: Gst.Format): [boolean, number]
  • Queries the peer pad of a given sink pad for the total stream duration.

    Parameters

    Returns [boolean, number]

  • peer_query_position(format: Gst.Format): [boolean, number]
  • proxy_query_accept_caps(query: Gst.Query): boolean
  • Checks if all internally linked pads of pad accepts the caps in query and returns the intersection of the results.

    This function is useful as a default accept caps query function for an element that can handle any stream format, but requires caps that are acceptable for all opposite pads.

    Parameters

    • query: Gst.Query

      an ACCEPT_CAPS #GstQuery.

    Returns boolean

  • proxy_query_caps(query: Gst.Query): boolean
  • Calls gst_pad_query_caps() for all internally linked pads of pad and returns the intersection of the results.

    This function is useful as a default caps query function for an element that can handle any stream format, but requires all its pads to have the same caps. Two such elements are tee and adder.

    Parameters

    Returns boolean

  • Pulls a buffer from the peer pad or fills up a provided buffer.

    This function will first trigger the pad block signal if it was installed.

    When pad is not linked #GST_FLOW_NOT_LINKED is returned else this function returns the result of gst_pad_get_range() on the peer pad. See gst_pad_get_range() for a list of return values and for the semantics of the arguments of this function.

    If buffer points to a variable holding %NULL, a valid new #GstBuffer will be placed in buffer when this function returns #GST_FLOW_OK. The new buffer must be freed with gst_buffer_unref() after usage. When this function returns any other result value, buffer will still point to %NULL.

    When buffer points to a variable that points to a valid #GstBuffer, the buffer will be filled with the result data when this function returns #GST_FLOW_OK. When this function returns any other result value, buffer will be unchanged. If the provided buffer is larger than size, only size bytes will be filled in the result buffer and its size will be updated accordingly.

    Note that less than size bytes can be returned in buffer when, for example, an EOS condition is near or when buffer is not large enough to hold size bytes. The caller should check the result buffer size to get the result size.

    Parameters

    • offset: number

      The start offset of the buffer

    • size: number

      The length of the buffer

    Returns [Gst.FlowReturn, Gst.Buffer]

  • Pushes a buffer to the peer of pad.

    This function will call installed block probes before triggering any installed data probes.

    The function proceeds calling gst_pad_chain() on the peer pad and returns the value from that function. If pad has no peer, #GST_FLOW_NOT_LINKED will be returned.

    In all cases, success or failure, the caller loses its reference to buffer after calling this function.

    Parameters

    • buffer: Gst.Buffer

      the #GstBuffer to push returns GST_FLOW_ERROR if not.

    Returns Gst.FlowReturn

  • Sends the event to the peer of the given pad. This function is mainly used by elements to send events to their peer elements.

    This function takes ownership of the provided event so you should gst_event_ref() it if you want to reuse the event after this call.

    Parameters

    • event: Gst.Event

      the #GstEvent to send to the pad.

    Returns boolean

  • Pushes a buffer list to the peer of pad.

    This function will call installed block probes before triggering any installed data probes.

    The function proceeds calling the chain function on the peer pad and returns the value from that function. If pad has no peer, #GST_FLOW_NOT_LINKED will be returned. If the peer pad does not have any installed chainlist function every group buffer of the list will be merged into a normal #GstBuffer and chained via gst_pad_chain().

    In all cases, success or failure, the caller loses its reference to list after calling this function.

    Parameters

    • list: Gst.BufferList

      the #GstBufferList to push returns GST_FLOW_ERROR if not.

    Returns Gst.FlowReturn

  • Dispatches a query to a pad. The query should have been allocated by the caller via one of the type-specific allocation functions. The element that the pad belongs to is responsible for filling the query with an appropriate response, which should then be parsed with a type-specific query parsing function.

    Again, the caller is responsible for both the allocation and deallocation of the query structure.

    Please also note that some queries might need a running pipeline to work.

    Parameters

    • query: Gst.Query

      the #GstQuery to perform.

    Returns boolean

  • query_accept_caps(caps: Gst.Caps): boolean
  • Gets the capabilities this pad can produce or consume. Note that this method doesn't necessarily return the caps set by sending a gst_event_new_caps() - use gst_pad_get_current_caps() for that instead. gst_pad_query_caps returns all possible caps a pad can operate with, using the pad's CAPS query function, If the query fails, this function will return filter, if not %NULL, otherwise ANY.

    When called on sinkpads filter contains the caps that upstream could produce in the order preferred by upstream. When called on srcpads filter contains the caps accepted by downstream in the preferred order. filter might be %NULL but if it is not %NULL the returned caps will be a subset of filter.

    Note that this function does not return writable #GstCaps, use gst_caps_make_writable() before modifying the caps.

    Parameters

    • filter: Gst.Caps

      suggested #GstCaps, or %NULL

    Returns Gst.Caps

  • query_convert(src_format: Gst.Format, src_val: number, dest_format: Gst.Format): [boolean, number]
  • Queries a pad to convert src_val in src_format to dest_format.

    Parameters

    • src_format: Gst.Format

      a #GstFormat to convert from.

    • src_val: number

      a value to convert.

    • dest_format: Gst.Format

      the #GstFormat to convert to.

    Returns [boolean, number]

  • Invokes the default query handler for the given pad. The query is sent to all pads internally linked to pad. Note that if there are many possible sink pads that are internally linked to pad, only one will be sent the query. Multi-sinkpad elements should implement custom query handlers.

    Parameters

    • parent: Gst.Object

      the parent of pad or %NULL

    • query: Gst.Query

      the #GstQuery to handle.

    Returns boolean

  • query_duration(format: Gst.Format): [boolean, number]
  • query_position(format: Gst.Format): [boolean, number]
  • ref(...args: any[]): any
  • Increments the reference count on object. This function does not take the lock on object because it relies on atomic refcounting.

    This object returns the input parameter to ease writing constructs like : result = gst_object_ref (object->parent);

    Parameters

    • Rest ...args: any[]

    Returns any

  • Increase the reference count of object, and possibly remove the [floating][floating-ref] reference, if object has a floating reference.

    In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.

    Since GLib 2.56, the type of object will be propagated to the return type under the same conditions as for g_object_ref().

    Returns GObject.Object

  • remove_probe(id: number): void
  • run_dispose(): void
  • Releases all references to other objects. This can be used to break reference cycles.

    This function should only be called from object system implementations.

    Returns void

  • Sends the event to the pad. This function can be used by applications to send events in the pipeline.

    If pad is a source pad, event should be an upstream event. If pad is a sink pad, event should be a downstream event. For example, you would not send a #GST_EVENT_EOS on a src pad; EOS events only propagate downstream. Furthermore, some downstream events have to be serialized with data flow, like EOS, while some can travel out-of-band, like #GST_EVENT_FLUSH_START. If the event needs to be serialized with data flow, this function will take the pad's stream lock while calling its event function.

    To find out whether an event type is upstream, downstream, or downstream and serialized, see #GstEventTypeFlags, gst_event_type_get_flags(), #GST_EVENT_IS_UPSTREAM, #GST_EVENT_IS_DOWNSTREAM, and #GST_EVENT_IS_SERIALIZED. Note that in practice that an application or plugin doesn't need to bother itself with this information; the core handles all necessary locks and checks.

    This function takes ownership of the provided event so you should gst_event_ref() it if you want to reuse the event after this call.

    Parameters

    • event: Gst.Event

      the #GstEvent to send to the pad.

    Returns boolean

  • Sets the given activate function for pad. The activate function will dispatch to gst_pad_activate_mode() to perform the actual activation. Only makes sense to set on sink pads.

    Call this function if your sink pad can start a pull-based task.

    Parameters

    Returns void

  • set_active(active: boolean): boolean
  • Activates or deactivates the given pad. Normally called from within core state change functions.

    If active, makes sure the pad is active. If it is already active, either in push or pull mode, just return. Otherwise dispatches to the pad's activate function to perform the actual activation.

    If not active, calls gst_pad_activate_mode() with the pad's current mode and a %FALSE argument.

    Parameters

    • active: boolean

      whether or not the pad should be active.

    Returns boolean

  • Sets the given chain function for the pad. The chain function is called to process a #GstBuffer input buffer. see #GstPadChainFunction for more details.

    Parameters

    Returns void

  • Sets the given chain list function for the pad. The chainlist function is called to process a #GstBufferList input buffer list. See #GstPadChainListFunction for more details.

    Parameters

    Returns void

  • set_control_binding_disabled(property_name: string, disabled: boolean): void
  • This function is used to disable the control bindings on a property for some time, i.e. gst_object_sync_values() will do nothing for the property.

    Parameters

    • property_name: string

      property to disable

    • disabled: boolean

      boolean that specifies whether to disable the controller or not.

    Returns void

  • set_control_bindings_disabled(disabled: boolean): void
  • This function is used to disable all controlled properties of the object for some time, i.e. gst_object_sync_values() will do nothing.

    Parameters

    • disabled: boolean

      boolean that specifies whether to disable the controller or not.

    Returns void

  • set_control_rate(control_rate: number): void
  • Change the control-rate for this object. Audio processing #GstElement objects will use this rate to sub-divide their processing loop and call gst_object_sync_values() in between. The length of the processing segment should be up to control-rate nanoseconds.

    The control-rate should not change if the element is in %GST_STATE_PAUSED or %GST_STATE_PLAYING.

    Parameters

    • control_rate: number

      the new control-rate in nanoseconds.

    Returns void

  • set_data(key: string, data?: object): void
  • Each object carries around a table of associations from strings to pointers. This function lets you set an association.

    If the object already had an association with that name, the old association will be destroyed.

    Internally, the key is converted to a #GQuark using g_quark_from_string(). This means a copy of key is kept permanently (even after object has been finalized) — so it is recommended to only use a small, bounded set of values for key in your program, to avoid the #GQuark storage growing unbounded.

    Parameters

    • key: string

      name of the key

    • Optional data: object

      data to associate with that key

    Returns void

  • set_element_private(priv: object): void
  • Set the given private data gpointer on the pad. This function can only be used by the element that owns the pad. No locking is performed in this function.

    Parameters

    • priv: object

      The private data to attach to the pad.

    Returns void

  • Sets the given getrange function for the pad. The getrange function is called to produce a new #GstBuffer to start the processing pipeline. see #GstPadGetRangeFunction for a description of the getrange function.

    Parameters

    Returns void

  • Sets the given link function for the pad. It will be called when the pad is linked with another pad.

    The return value #GST_PAD_LINK_OK should be used when the connection can be made.

    The return value #GST_PAD_LINK_REFUSED should be used when the connection cannot be made for some reason.

    If link is installed on a source pad, it should call the #GstPadLinkFunction of the peer sink pad, if present.

    Parameters

    Returns void

  • set_name(name: string): boolean
  • Sets the name of object, or gives object a guaranteed unique name (if name is %NULL). This function makes a copy of the provided name, so the caller retains ownership of the name it sent.

    Parameters

    • name: string

      new name of object

    Returns boolean

  • set_offset(offset: number): void
  • Set the offset that will be applied to the running time of pad.

    Parameters

    • offset: number

      the offset

    Returns void

  • Sets the parent of object to parent. The object's reference count will be incremented, and any floating reference will be removed (see gst_object_ref_sink()).

    Parameters

    Returns boolean

  • set_property(property_name: string, value?: any): void
  • Sets the given unlink function for the pad. It will be called when the pad is unlinked.

    Note that the pad's lock is already held when the unlink function is called, so most pad functions cannot be called from within the callback.

    Parameters

    Returns void

  • Starts a task that repeatedly calls func with user_data. This function is mostly used in pad activation functions to start the dataflow. The #GST_PAD_STREAM_LOCK of pad will automatically be acquired before func is called.

    Parameters

    Returns boolean

  • steal_data(key?: string): object
  • Remove a specified datum from the object's data associations, without invoking the association's destroy handler.

    Parameters

    • Optional key: string

      name of the key

    Returns object

  • steal_qdata(quark: number): object
  • This function gets back user data pointers stored via g_object_set_qdata() and removes the data from object without invoking its destroy() function (if any was set). Usually, calling this function is only required to update user data pointers with a destroy notifier, for example:

    void
    object_add_to_user_list (GObject *object,
    const gchar *new_string)
    {
    // the quark, naming the object data
    GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
    // retrieve the old string list
    GList *list = g_object_steal_qdata (object, quark_string_list);

    // prepend new string
    list = g_list_prepend (list, g_strdup (new_string));
    // this changed 'list', so we need to set it again
    g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
    }
    static void
    free_string_list (gpointer data)
    {
    GList *node, *list = data;

    for (node = list; node; node = node->next)
    g_free (node->data);
    g_list_free (list);
    }

    Using g_object_get_qdata() in the above example, instead of g_object_steal_qdata() would have left the destroy function set, and thus the partial string list would have been freed upon g_object_set_qdata_full().

    Parameters

    • quark: number

      A #GQuark, naming the user data pointer

    Returns object

  • Iterates all sticky events on pad and calls foreach_func for every event. If foreach_func returns %FALSE the iteration is immediately stopped.

    Parameters

    Returns void

  • stop_task(): boolean
  • Stop the task of pad. This function will also make sure that the function executed by the task will effectively stop if not called from the GstTaskFunction.

    This function will deadlock if called from the GstTaskFunction of the task. Use gst_task_pause() instead.

    Regardless of whether the pad has a task, the stream lock is acquired and released so as to ensure that streaming through this pad has finished.

    Returns boolean

  • suggest_next_sync(): number
  • sync_values(timestamp: number): boolean
  • Sets the properties of the object, according to the #GstControlSources that (maybe) handle them and for the given timestamp.

    If this function fails, it is most likely the application developers fault. Most probably the control sources are not setup correctly.

    Parameters

    • timestamp: number

      the time that should be processed

    Returns boolean

  • thaw_notify(): void
  • Reverts the effect of a previous call to g_object_freeze_notify(). The freeze count is decreased on object and when it reaches zero, queued "notify" signals are emitted.

    Duplicate notifications for each property are squashed so that at most one #GObject::notify signal is emitted for each property, in the reverse order in which they have been queued.

    It is an error to call this function when the freeze count is zero.

    Returns void

  • unlink(sinkpad: Gst.Pad): boolean
  • Unlinks the source pad from the sink pad. Will emit the #GstPad::unlinked signal on both pads.

    Parameters

    • sinkpad: Gst.Pad

      the sink #GstPad to unlink.

    Returns boolean

  • unparent(): void
  • Clear the parent of object, removing the associated reference. This function decreases the refcount of object.

    MT safe. Grabs and releases object's lock.

    Returns void

  • unref(): void
  • Decrements the reference count on object. If reference count hits zero, destroy object. This function does not take the lock on object as it relies on atomic refcounting.

    The unref method should never be called with the LOCK held since this might deadlock the dispose function.

    Returns void

  • use_fixed_caps(): void
  • A helper function you can use that sets the FIXED_CAPS flag This way the default CAPS query will always return the negotiated caps or in case the pad is not negotiated, the padtemplate caps.

    The negotiated caps are the caps of the last CAPS event that passed on the pad. Use this function on a pad that, once it negotiated to a CAPS, cannot be renegotiated to something else.

    Returns void

  • vfunc_constructed(): void
  • vfunc_dispatch_properties_changed(n_pspecs: number, pspecs: ParamSpec): void
  • vfunc_dispose(): void
  • vfunc_finalize(): void
  • vfunc_get_property(property_id: number, value?: any, pspec?: ParamSpec): void
  • vfunc_linked(peer: Gst.Pad): void
  • Emits a "notify" signal for the property property_name on object.

    When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.

    Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.

    virtual

    Parameters

    Returns void

  • vfunc_set_property(property_id: number, value?: any, pspec?: ParamSpec): void
  • vfunc_unlinked(peer: Gst.Pad): void
  • watch_closure(closure: TClosure<any, any>): void
  • This function essentially limits the life time of the closure to the life time of the object. That is, when the object is finalized, the closure is invalidated by calling g_closure_invalidate() on it, in order to prevent invocations of the closure with a finalized (nonexisting) object. Also, g_object_ref() and g_object_unref() are added as marshal guards to the closure, to ensure that an extra reference count is held on object during invocation of the closure. Usually, this function will be called on closures that use this object as closure data.

    Parameters

    • closure: TClosure<any, any>

      #GClosure to watch

    Returns void

  • check_uniqueness(list: Gst.Object[], name: string): boolean
  • Checks to see if there is any object named name in list. This function does not do any locking of any kind. You might want to protect the provided list with the lock of the owner of the list. This function will lock each #GstObject in the list to compare the name, so be careful when passing a list with a locked object.

    Parameters

    • list: Gst.Object[]

      a list of #GstObject to check through

    • name: string

      the name to search for

    Returns boolean

  • compat_control(what: number, data: object): number
  • A default deep_notify signal callback for an object. The user data should contain a pointer to an array of strings that should be excluded from the notify. The default handler will print the new value of the property using g_print.

    MT safe. This function grabs and releases object's LOCK for getting its path string.

    Parameters

    • object: GObject.Object

      the #GObject that signalled the notify.

    • orig: Gst.Object

      a #GstObject that initiated the notify.

    • pspec: ParamSpec

      a #GParamSpec of the property.

    • excluded_props: string[]

      a set of user-specified properties to exclude or %NULL to show all changes.

    Returns void

  • Find the #GParamSpec with the given name for an interface. Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().

    Parameters

    • g_iface: TypeInterface

      any interface vtable for the interface, or the default vtable for the interface

    • property_name: string

      name of a property to look up.

    Returns ParamSpec

  • Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created #GParamSpec, but normally g_object_class_override_property() will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property.

    This function is meant to be called from the interface's default vtable initialization function (the class_init member of #GTypeInfo.) It must not be called after after class_init has been called for any object types implementing this interface.

    If pspec is a floating reference, it will be consumed.

    Parameters

    • g_iface: TypeInterface

      any interface vtable for the interface, or the default vtable for the interface.

    • pspec: ParamSpec

      the #GParamSpec for the new property

    Returns void

  • Lists the properties of an interface.Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().

    Parameters

    • g_iface: TypeInterface

      any interface vtable for the interface, or the default vtable for the interface

    Returns ParamSpec[]

  • Creates a new pad with the given name in the given direction. If name is %NULL, a guaranteed unique name (across all pads) will be assigned. This function makes a copy of the name so you can safely free the name.

    Parameters

    • name: string

      the name of the new pad.

    • direction: Gst.PadDirection

      the #GstPadDirection of the pad.

    Returns Gst.Pad

  • Creates a new pad with the given name from the given static template. If name is %NULL, a guaranteed unique name (across all pads) will be assigned. This function makes a copy of the name so you can safely free the name.

    Parameters

    Returns Gst.Pad

  • Creates a new pad with the given name from the given template. If name is %NULL, a guaranteed unique name (across all pads) will be assigned. This function makes a copy of the name so you can safely free the name.

    Parameters

    • templ: Gst.PadTemplate

      the pad template to use

    • name: string

      the name of the pad

    Returns Gst.Pad

  • Creates a new instance of a #GObject subtype and sets its properties.

    Construction parameters (see %G_PARAM_CONSTRUCT, %G_PARAM_CONSTRUCT_ONLY) which are not explicitly specified are set to their default values.

    Parameters

    • object_type: GType<unknown>

      the type id of the #GObject subtype to instantiate

    • parameters: GObject.Parameter[]

      an array of #GParameter

    Returns GObject.Object

  • Atomically modifies a pointer to point to a new object. The reference count of oldobj is decreased and the reference count of newobj is increased.

    Either newobj and the value pointed to by oldobj may be %NULL.

    Parameters

    • oldobj: Gst.Object

      pointer to a place of a #GstObject to replace

    • newobj: Gst.Object

      a new #GstObject

    Returns [boolean, Gst.Object]

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