Aggregator

Manages a set of pads with the purpose of aggregating their buffers. Control is given to the subclass when all pads have data.

* Base class for mixers and muxers. Subclasses should at least implement the #GstAggregatorClass.aggregate() virtual method.

* Installs a #GstPadChainFunction, a #GstPadEventFullFunction and a #GstPadQueryFunction to queue all serialized data packets per sink pad. Subclasses should not overwrite those, but instead implement #GstAggregatorClass.sink_event() and #GstAggregatorClass.sink_query() as needed.

* When data is queued on all pads, the aggregate vmethod is called.

* One can peek at the data on any given GstAggregatorPad with the gst_aggregator_pad_peek_buffer () method, and remove it from the pad with the gst_aggregator_pad_pop_buffer () method. When a buffer has been taken with pop_buffer (), a new buffer can be queued on that pad.

* If the subclass wishes to push a buffer downstream in its aggregate implementation, it should do so through the gst_aggregator_finish_buffer () method. This method will take care of sending and ordering mandatory events such as stream start, caps and segment.

* Same goes for EOS events, which should not be pushed directly by the subclass, it should instead return GST_FLOW_EOS in its aggregate implementation.

* Note that the aggregator logic regarding gap event handling is to turn these into gap buffers with matching PTS and duration. It will also flag these buffers with GST_BUFFER_FLAG_GAP and GST_BUFFER_FLAG_DROPPABLE to ease their identification and subsequent processing.

* Subclasses must use (a subclass of) #GstAggregatorPad for both their sink and source pads. See gst_element_class_add_static_pad_template_with_gtype().

This class used to live in gst-plugins-bad and was moved to core.

Constructors

this
this(GstAggregator* gstAggregator, bool ownedRef)

Sets our main struct and passes it to the parent class.

Members

Functions

finishBuffer
GstFlowReturn finishBuffer(Buffer buffer)

This method will push the provided output buffer downstream. If needed, mandatory events such as stream-start, caps, and segment events will be sent before pushing the buffer.

getAggregatorStruct
GstAggregator* getAggregatorStruct(bool transferOwnership)

Get the main Gtk struct

getAllocator
void getAllocator(Allocator allocator, AllocationParams params)

Lets #GstAggregator sub-classes get the memory @allocator acquired by the base class and its @params.

getBufferPool
BufferPool getBufferPool()
getLatency
GstClockTime getLatency()

Retrieves the latency values reported by @self in response to the latency query, or %GST_CLOCK_TIME_NONE if there is not live source connected and the element will not wait for the clock.

getStruct
void* getStruct()

the main Gtk struct as a void*

setLatency
void setLatency(GstClockTime minLatency, GstClockTime maxLatency)

Lets #GstAggregator sub-classes tell the baseclass what their internal latency is. Will also post a LATENCY message on the bus so the pipeline can reconfigure its global latency.

setSrcCaps
void setSrcCaps(Caps caps)

Sets the caps to be used on the src pad.

simpleGetNextTime
GstClockTime simpleGetNextTime()

This is a simple #GstAggregator::get_next_time implementation that just looks at the #GstSegment on the srcpad of the aggregator and bases the next time on the running time there.

Static functions

getType
GType getType()

Variables

gstAggregator
GstAggregator* gstAggregator;

the main Gtk struct

Inherited Members

From Element

gstElement
GstElement* gstElement;

the main Gtk struct

getElementStruct
GstElement* getElementStruct(bool transferOwnership)

Get the main Gtk struct

getStruct
void* getStruct()

the main Gtk struct as a void*

queryPosition
long queryPosition()

Queries an element for the stream position. This is a convenience function for gstreamerD.

queryDuration
long queryDuration()

Queries an element for the stream duration. This is a convenience function for gstreamerD.

location
void location(string set)

This set's the filename for a filesrc element.

caps
void caps(Caps cp)

Set the caps property of an Element.

seek
int seek(long time_nanoseconds)

For your convenience in gstreamerD: you can seek to the position of the pipeline measured in time_nanoseconds.

pads
Pad[] pads()

Get's all the pads from an element in a Pad[].

getType
GType getType()
makeFromUri
Element makeFromUri(GstURIType type, string uri, string elementname)

Creates an element for handling the given URI.

register
bool register(Plugin plugin, string name, uint rank, GType type)

Create a new elementfactory capable of instantiating objects of the @type and add the factory to @plugin.

stateChangeReturnGetName
string stateChangeReturnGetName(GstStateChangeReturn stateRet)

Gets a string representing the given state change result.

stateGetName
string stateGetName(GstState state)

Gets a string representing the given state.

abortState
void abortState()

Abort the state change of the element. This function is used by elements that do asynchronous state changes and find out something is wrong.

addPad
bool addPad(Pad pad)

Adds a pad (link point) to @element. @pad's parent will be set to @element; see gst_object_set_parent() for refcounting information.

addPropertyDeepNotifyWatch
gulong addPropertyDeepNotifyWatch(string propertyName, bool includeValue)
addPropertyNotifyWatch
gulong addPropertyNotifyWatch(string propertyName, bool includeValue)
callAsync
void callAsync(GstElementCallAsyncFunc func, void* userData, GDestroyNotify destroyNotify)

Calls @func from another thread and passes @user_data to it. This is to be used for cases when a state change has to be performed from a streaming thread, directly via gst_element_set_state() or indirectly e.g. via SEEK events.

changeState
GstStateChangeReturn changeState(GstStateChange transition)

Perform @transition on @element.

continueState
GstStateChangeReturn continueState(GstStateChangeReturn ret)

Commit the state change of the element and proceed to the next pending state if any. This function is used by elements that do asynchronous state changes. The core will normally call this method automatically when an element returned %GST_STATE_CHANGE_SUCCESS from the state change function.

createAllPads
void createAllPads()

Creates a pad for each pad template that is always available. This function is only useful during object initialization of subclasses of #GstElement.

foreachPad
bool foreachPad(GstElementForeachPadFunc func, void* userData)

Call @func with @user_data for each of @element's pads. @func will be called exactly once for each pad that exists at the time of this call, unless one of the calls to @func returns %FALSE in which case we will stop iterating pads and return early. If new pads are added or pads are removed while pads are being iterated, this will not be taken into account until next time this function is used.

foreachSinkPad
bool foreachSinkPad(GstElementForeachPadFunc func, void* userData)

Call @func with @user_data for each of @element's sink pads. @func will be called exactly once for each sink pad that exists at the time of this call, unless one of the calls to @func returns %FALSE in which case we will stop iterating pads and return early. If new sink pads are added or sink pads are removed while the sink pads are being iterated, this will not be taken into account until next time this function is used.

foreachSrcPad
bool foreachSrcPad(GstElementForeachPadFunc func, void* userData)

Call @func with @user_data for each of @element's source pads. @func will be called exactly once for each source pad that exists at the time of this call, unless one of the calls to @func returns %FALSE in which case we will stop iterating pads and return early. If new source pads are added or source pads are removed while the source pads are being iterated, this will not be taken into account until next time this function is used.

getBaseTime
GstClockTime getBaseTime()

Returns the base time of the element. The base time is the absolute time of the clock when this element was last put to PLAYING. Subtracting the base time from the clock time gives the running time of the element.

getBus
Bus getBus()

Returns the bus of the element. Note that only a #GstPipeline will provide a bus for the application.

getClock
Clock getClock()

Gets the currently configured clock of the element. This is the clock as was last set with gst_element_set_clock().

getCompatiblePad
Pad getCompatiblePad(Pad pad, Caps caps)

Looks for an unlinked pad to which the given pad can link. It is not guaranteed that linking the pads will work, though it should work in most cases.

getCompatiblePadTemplate
PadTemplate getCompatiblePadTemplate(PadTemplate compattempl)

Retrieves a pad template from @element that is compatible with @compattempl. Pads from compatible templates can be linked together.

getContext
Context getContext(string contextType)

Gets the context with @context_type set on the element or NULL.

getContextUnlocked
Context getContextUnlocked(string contextType)

Gets the context with @context_type set on the element or NULL.

getContexts
ListG getContexts()

Gets the contexts set on the element.

getFactory
ElementFactory getFactory()

Retrieves the factory that was used to create this element.

getMetadata
string getMetadata(string key)

Get metadata with @key in @klass.

getPadTemplate
PadTemplate getPadTemplate(string name)

Retrieves a padtemplate from @element with the given name.

getPadTemplateList
ListG getPadTemplateList()

Retrieves a list of the pad templates associated with @element. The list must not be modified by the calling code.

getRequestPad
Pad getRequestPad(string name)

Retrieves a pad from the element by name (e.g. "src_\%d"). This version only retrieves request pads. The pad should be released with gst_element_release_request_pad().

getStartTime
GstClockTime getStartTime()

Returns the start time of the element. The start time is the running time of the clock when this element was last put to PAUSED.

getState
GstStateChangeReturn getState(GstState state, GstState pending, GstClockTime timeout)

Gets the state of the element.

getStaticPad
Pad getStaticPad(string name)

Retrieves a pad from @element by name. This version only retrieves already-existing (i.e. 'static') pads.

isLockedState
bool isLockedState()

Checks if the state of an element is locked. If the state of an element is locked, state changes of the parent don't affect the element. This way you can leave currently unused elements inside bins. Just lock their state before changing the state from #GST_STATE_NULL.

iteratePads
Iterator iteratePads()

Retrieves an iterator of @element's pads. The iterator should be freed after usage. Also more specialized iterators exists such as gst_element_iterate_src_pads() or gst_element_iterate_sink_pads().

iterateSinkPads
Iterator iterateSinkPads()

Retrieves an iterator of @element's sink pads.

iterateSrcPads
Iterator iterateSrcPads()

Retrieves an iterator of @element's source pads.

link
bool link(Element dest)

Links @src to @dest. The link must be from source to destination; the other direction will not be tried. The function looks for existing pads that aren't linked yet. It will request new pads if necessary. Such pads need to be released manually when unlinking. If multiple links are possible, only one is established.

linkFiltered
bool linkFiltered(Element dest, Caps filter)

Links @src to @dest using the given caps as filtercaps. The link must be from source to destination; the other direction will not be tried. The function looks for existing pads that aren't linked yet. It will request new pads if necessary. If multiple links are possible, only one is established.

linkPads
bool linkPads(string srcpadname, Element dest, string destpadname)

Links the two named pads of the source and destination elements. Side effect is that if one of the pads has no parent, it becomes a child of the parent of the other element. If they have different parents, the link fails.

linkPadsFiltered
bool linkPadsFiltered(string srcpadname, Element dest, string destpadname, Caps filter)

Links the two named pads of the source and destination elements. Side effect is that if one of the pads has no parent, it becomes a child of the parent of the other element. If they have different parents, the link fails. If @caps is not %NULL, makes sure that the caps of the link is a subset of @caps.

linkPadsFull
bool linkPadsFull(string srcpadname, Element dest, string destpadname, GstPadLinkCheck flags)

Links the two named pads of the source and destination elements. Side effect is that if one of the pads has no parent, it becomes a child of the parent of the other element. If they have different parents, the link fails.

lostState
void lostState()

Brings the element to the lost state. The current state of the element is copied to the pending state so that any call to gst_element_get_state() will return %GST_STATE_CHANGE_ASYNC.

messageFull
void messageFull(GstMessageType type, GQuark domain, int code, string text, string debug_, string file, string function_, int line)

Post an error, warning or info message on the bus from inside an element.

messageFullWithDetails
void messageFullWithDetails(GstMessageType type, GQuark domain, int code, string text, string debug_, string file, string function_, int line, Structure structure)

Post an error, warning or info message on the bus from inside an element.

noMorePads
void noMorePads()

Use this function to signal that the element does not expect any more pads to show up in the current pipeline. This function should be called whenever pads have been added by the element itself. Elements with #GST_PAD_SOMETIMES pad templates use this in combination with autopluggers to figure out that the element is done initializing its pads.

postMessage
bool postMessage(Message message)

Post a message on the element's #GstBus. This function takes ownership of the message; if you want to access the message after this call, you should add an additional reference before calling.

provideClock
Clock provideClock()

Get the clock provided by the given element. > An element is only required to provide a clock in the PAUSED > state. Some elements can provide a clock in other states.

query
bool query(Query query)

Performs a query on the given element.

queryConvert
bool queryConvert(GstFormat srcFormat, long srcVal, GstFormat destFormat, long destVal)

Queries an element to convert @src_val in @src_format to @dest_format.

queryDuration
bool queryDuration(GstFormat format, long duration)

Queries an element (usually top-level pipeline or playbin element) for the total stream duration in nanoseconds. This query will only work once the pipeline is prerolled (i.e. reached PAUSED or PLAYING state). The application will receive an ASYNC_DONE message on the pipeline bus when that is the case.

queryPosition
bool queryPosition(GstFormat format, long cur)

Queries an element (usually top-level pipeline or playbin element) for the stream position in nanoseconds. This will be a value between 0 and the stream duration (if the stream duration is known). This query will usually only work once the pipeline is prerolled (i.e. reached PAUSED or PLAYING state). The application will receive an ASYNC_DONE message on the pipeline bus when that is the case.

releaseRequestPad
void releaseRequestPad(Pad pad)

Makes the element free the previously requested pad as obtained with gst_element_request_pad().

removePad
bool removePad(Pad pad)

Removes @pad from @element. @pad will be destroyed if it has not been referenced elsewhere using gst_object_unparent().

removePropertyNotifyWatch
void removePropertyNotifyWatch(gulong watchId)
requestPad
Pad requestPad(PadTemplate templ, string name, Caps caps)

Retrieves a request pad from the element according to the provided template. Pad templates can be looked up using gst_element_factory_get_static_pad_templates().

seek
bool seek(double rate, GstFormat format, GstSeekFlags flags, GstSeekType startType, long start, GstSeekType stopType, long stop)

Sends a seek event to an element. See gst_event_new_seek() for the details of the parameters. The seek event is sent to the element using gst_element_send_event().

seekSimple
bool seekSimple(GstFormat format, GstSeekFlags seekFlags, long seekPos)

Simple API to perform a seek on the given element, meaning it just seeks to the given position relative to the start of the stream. For more complex operations like segment seeks (e.g. for looping) or changing the playback rate or seeking relative to the last configured playback segment you should use gst_element_seek().

sendEvent
bool sendEvent(Event event)

Sends an event to an element. If the element doesn't implement an event handler, the event will be pushed on a random linked sink pad for downstream events or a random linked source pad for upstream events.

setBaseTime
void setBaseTime(GstClockTime time)

Set the base time of an element. See gst_element_get_base_time().

setBus
void setBus(Bus bus)

Sets the bus of the element. Increases the refcount on the bus. For internal use only, unless you're testing elements.

setClock
bool setClock(Clock clock)

Sets the clock for the element. This function increases the refcount on the clock. Any previously set clock on the object is unreffed.

setContext
void setContext(Context context)

Sets the context of the element. Increases the refcount of the context.

setLockedState
bool setLockedState(bool lockedState)

Locks the state of an element, so state changes of the parent don't affect this element anymore.

setStartTime
void setStartTime(GstClockTime time)

Set the start time of an element. The start time of the element is the running time of the element when it last went to the PAUSED state. In READY or after a flushing seek, it is set to 0.

setState
GstStateChangeReturn setState(GstState state)

Sets the state of the element. This function will try to set the requested state by going through all the intermediary states and calling the class's state change function for each.

syncStateWithParent
bool syncStateWithParent()

Tries to change the state of the element to the same as its parent. If this function returns %FALSE, the state of element is undefined.

unlink
void unlink(Element dest)

Unlinks all source pads of the source element with all sink pads of the sink element to which they are linked.

unlinkPads
void unlinkPads(string srcpadname, Element dest, string destpadname)

Unlinks the two named pads of the source and destination elements.

addOnNoMorePads
gulong addOnNoMorePads(void delegate(Element) dlg, ConnectFlags connectFlags)

This signals that the element will not generate more dynamic pads. Note that this signal will usually be emitted from the context of the streaming thread.

addOnPadAdded
gulong addOnPadAdded(void delegate(Pad, Element) dlg, ConnectFlags connectFlags)

a new #GstPad has been added to the element. Note that this signal will usually be emitted from the context of the streaming thread. Also keep in mind that if you add new elements to the pipeline in the signal handler you will need to set them to the desired target state with gst_element_set_state() or gst_element_sync_state_with_parent().

addOnPadRemoved
gulong addOnPadRemoved(void delegate(Pad, Element) dlg, ConnectFlags connectFlags)

a #GstPad has been removed from the element

Meta

Since

1.14