Pipeline

A #GstPipeline is a special #GstBin used as the toplevel container for the filter graph. The #GstPipeline will manage the selection and distribution of a global #GstClock as well as provide a #GstBus to the application.

gst_pipeline_new() is used to create a pipeline. when you are done with the pipeline, use gst_object_unref() to free its resources including all added #GstElement objects (if not otherwise referenced).

Elements are added and removed from the pipeline using the #GstBin methods like gst_bin_add() and gst_bin_remove() (see #GstBin).

Before changing the state of the #GstPipeline (see #GstElement) a #GstBus can be retrieved with gst_pipeline_get_bus(). This bus can then be used to receive #GstMessage from the elements in the pipeline.

By default, a #GstPipeline will automatically flush the pending #GstBus messages when going to the NULL state to ensure that no circular references exist when no messages are read from the #GstBus. This behaviour can be changed with gst_pipeline_set_auto_flush_bus().

When the #GstPipeline performs the PAUSED to PLAYING state change it will select a clock for the elements. The clock selection algorithm will by default select a clock provided by an element that is most upstream (closest to the source). For live pipelines (ones that return #GST_STATE_CHANGE_NO_PREROLL from the gst_element_set_state() call) this will select the clock provided by the live source. For normal pipelines this will select a clock provided by the sinks (most likely the audio sink). If no element provides a clock, a default #GstSystemClock is used.

The clock selection can be controlled with the gst_pipeline_use_clock() method, which will enforce a given clock on the pipeline. With gst_pipeline_auto_clock() the default clock selection algorithm can be restored.

A #GstPipeline maintains a running time for the elements. The running time is defined as the difference between the current clock time and the base time. When the pipeline goes to READY or a flushing seek is performed on it, the running time is reset to 0. When the pipeline is set from PLAYING to PAUSED, the current clock time is sampled and used to configure the base time for the elements when the pipeline is set to PLAYING again. The effect is that the running time (as the difference between the clock time and the base time) will count how much time was spent in the PLAYING state. This default behaviour can be changed with the gst_element_set_start_time() method.

class Pipeline : Bin {

protected

GstPipeline* gstPipeline;

GstPipeline* getPipelineStruct();

void* getStruct();

void setStruct(GObject* obj);

this(GstPipeline* gstPipeline, bool ownedRef);

static GType getType();

this(string name);

void autoClock();

bool getAutoFlushBus();

Bus getBus();

Clock getClock();

GstClockTime getDelay();

void setAutoFlushBus(bool autoFlush);

bool setClock(Clock clock);

void setDelay(GstClockTime delay);

void useClock(Clock clock);

}

Constructors

this this(GstPipeline* gstPipeline, bool ownedRef): Sets our main struct and passes it to the parent class.
this this(string name): Create a new pipeline with the given name.

Members

Functions

autoClock void autoClock(): Let @pipeline select a clock automatically. This is the default behaviour.
getAutoFlushBus bool getAutoFlushBus(): Check if @pipeline will automatically flush messages when going to the NULL state.
getBus Bus getBus(): Gets the #GstBus of @pipeline. The bus allows applications to receive #GstMessage packets.
getClock Clock getClock(): Gets the current clock used by @pipeline.
getDelay GstClockTime getDelay(): Get the configured delay (see gst_pipeline_set_delay()).
getPipelineStruct GstPipeline* getPipelineStruct(): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
setAutoFlushBus void setAutoFlushBus(bool autoFlush): Usually, when a pipeline goes from READY to NULL state, it automatically flushes all pending messages on the bus, which is done for refcounting purposes, to break circular references.
setClock bool setClock(Clock clock): Set the clock for @pipeline. The clock will be distributed to all the elements managed by the pipeline.
setDelay void setDelay(GstClockTime delay): Set the expected delay needed for all elements to perform the PAUSED to PLAYING state change. @delay will be added to the base time of the elements so that they wait an additional @delay amount of time before starting to process buffers and cannot be #GST_CLOCK_TIME_NONE.
setStruct void setStruct(GObject* obj): Undocumented in source. Be warned that the author may not have intended to support it.
useClock void useClock(Clock clock): Force @pipeline to use the given @clock. The pipeline will always use the given clock even if new clock providers are added to this pipeline.

Static functions

getType GType getType()

Variables

gstPipeline GstPipeline* gstPipeline;: the main Gtk struct

Inherited Members

From Bin

gstBin GstBin* gstBin;: the main Gtk struct
getBinStruct GstBin* getBinStruct(): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
setStruct void setStruct(GObject* obj): Undocumented in source. Be warned that the author may not have intended to support it.
__anonymous mixin ChildProxyT!(GstBin): Undocumented in source.
getType GType getType()
add bool add(Element element): Adds the given element to the bin. Sets the element's parent, and thus takes ownership of the element. An element can only be added to one bin.
findUnlinkedPad Pad findUnlinkedPad(GstPadDirection direction): Recursively looks for elements with an unlinked pad of the given direction within the specified bin and returns an unlinked pad if one is found, or %NULL otherwise. If a pad is found, the caller owns a reference to it and should use gst_object_unref() on the pad when it is not needed any longer.
getByInterface Element getByInterface(GType iface): Looks for an element inside the bin that implements the given interface. If such an element is found, it returns the element. You can cast this element to the given interface afterwards. If you want all elements that implement the interface, use gst_bin_iterate_all_by_interface(). This function recurses into child bins.
getByName Element getByName(string name): Gets the element with the given name from a bin. This function recurses into child bins.
getByNameRecurseUp Element getByNameRecurseUp(string name): Gets the element with the given name from this bin. If the element is not found, a recursion is performed on the parent bin.
iterateAllByInterface Iterator iterateAllByInterface(GType iface): Looks for all elements inside the bin that implements the given interface. You can safely cast all returned elements to the given interface. The function recurses inside child bins. The iterator will yield a series of #GstElement that should be unreffed after use.
iterateElements Iterator iterateElements(): Gets an iterator for the elements in this bin.
iterateRecurse Iterator iterateRecurse(): Gets an iterator for the elements in this bin. This iterator recurses into GstBin children.
iterateSinks Iterator iterateSinks(): Gets an iterator for all elements in the bin that have the #GST_ELEMENT_FLAG_SINK flag set.
iterateSorted Iterator iterateSorted(): Gets an iterator for the elements in this bin in topologically sorted order. This means that the elements are returned from the most downstream elements (sinks) to the sources.
iterateSources Iterator iterateSources(): Gets an iterator for all elements in the bin that have the #GST_ELEMENT_FLAG_SOURCE flag set.
recalculateLatency bool recalculateLatency(): Query @bin for the current latency using and reconfigures this latency to all the elements with a LATENCY event.
remove bool remove(Element element): Removes the element from the bin, unparenting it as well. Unparenting the element means that the element will be dereferenced, so if the bin holds the only reference to the element, the element will be freed in the process of removing it from the bin. If you want the element to still exist after removing, you need to call gst_object_ref() before removing it from the bin.
connectedSignals int[string] connectedSignals;: Undocumented in source.
onDoLatencyListeners bool delegate(Bin)[] onDoLatencyListeners;: Undocumented in source.
addOnDoLatency void addOnDoLatency(bool delegate(Bin) dlg, ConnectFlags connectFlags): Will be emitted when the bin needs to perform latency calculations. This signal is only emitted for toplevel bins or when async-handling is enabled.
callBackDoLatency int callBackDoLatency(GstBin* binStruct, Bin _bin): Undocumented in source. Be warned that the author may not have intended to support it.
onElementAddedListeners void delegate(Element, Bin)[] onElementAddedListeners;: Undocumented in source.
addOnElementAdded void addOnElementAdded(void delegate(Element, Bin) dlg, ConnectFlags connectFlags): Will be emitted after the element was added to the bin.
callBackElementAdded void callBackElementAdded(GstBin* binStruct, GstElement* element, Bin _bin): Undocumented in source. Be warned that the author may not have intended to support it.
onElementRemovedListeners void delegate(Element, Bin)[] onElementRemovedListeners;: Undocumented in source.
addOnElementRemoved void addOnElementRemoved(void delegate(Element, Bin) dlg, ConnectFlags connectFlags): Will be emitted after the element was removed from the bin.
callBackElementRemoved void callBackElementRemoved(GstBin* binStruct, GstElement* element, Bin _bin): Undocumented in source. Be warned that the author may not have intended to support it.