MediaGraph Class Reference

Directed acyclic graph of MediaNodes connected by MediaLinks. More...

#include <mediagraph.h>

Inheritance diagram for MediaGraph:

Collaboration diagram for MediaGraph:

Public Member Functions
	MediaGraph (ObjectBase *parent=nullptr)
	Constructs an empty graph.
virtual	~MediaGraph ()
	Destructor. Deletes all owned nodes.
Error	addNode (MediaNode *node)
	Adds a node to the graph. Takes ownership.
Error	removeNode (MediaNode *node)
	Removes a node from the graph.
const List< MediaNode * > &	nodes () const
	Returns all nodes in the graph.
MediaNode *	node (const String &name) const
	Finds a node by name.
MediaLink::Ptr	connect (MediaPort::Ptr output, MediaPort::Ptr input)
	Connects an output port to an input port.
MediaLink::Ptr	connect (MediaNode *source, int outputIndex, MediaNode *sink, int inputIndex)
	Connects nodes by port index.
MediaLink::Ptr	connect (MediaNode *source, const String &outputName, MediaNode *sink, const String &inputName)
	Connects nodes by port name.
Error	disconnect (MediaLink::Ptr link)
	Disconnects a link.
Error	disconnect (MediaPort::Ptr output, MediaPort::Ptr input)
	Disconnects the link between two specific ports.
const MediaLink::PtrList &	links () const
	Returns all links in the graph.
Error	validate () const
	Validates the graph topology.
List< MediaNode * >	topologicalSort () const
	Returns nodes in topological order (dependencies first).
List< MediaNode * >	sourceNodes () const
	Returns nodes with no input connections (source nodes).
List< MediaNode * >	sinkNodes () const
	Returns nodes with no output connections (sink nodes).
void	clear ()
	Removes all nodes and links.
Public Member Functions inherited from ObjectBase
	ObjectBase (ObjectBase *p=nullptr)
	Default ObjectBase constructor.
virtual	~ObjectBase ()
	Destructor. Emits aboutToDestroy, detaches from parent, and destroys children.
ObjectBase *	parent () const
	Returns the parent object, if one. nullptr if none.
void	setParent (ObjectBase *p)
	Sets the parent of this object. If the object already has a parent, it will be removed as a child from the old parent and added as a child to the new one.
const ObjectBaseList &	childList () const
	Returns a list of children of this object.
template<typename... Args>
int	registerSlot (Slot< Args... > *slot)
	Registers a slot with this object and assigns it an ID.
EventLoop *	eventLoop () const
	Returns the EventLoop this object is affiliated with.
void	moveToThread (EventLoop *loop)
	Changes the EventLoop affinity of this object.
int	startTimer (unsigned int intervalMs, bool singleShot=false)
	Starts a timer on this object's EventLoop.
void	stopTimer (int timerId)
	Stops a timer previously started with startTimer().
template<typename... Args>
PROMEKI_NAMESPACE_BEGIN void	connect (Signal< Args... > *signal, Slot< Args... > *slot)

Additional Inherited Members
Public Types inherited from ObjectBase
using	SlotVariantFunc = std::function< void(const VariantList &)>
	Function type for invoking a slot with a list of Variants.
Static Public Member Functions inherited from ObjectBase
static const MetaInfo &	metaInfo ()
	Returns the MetaInfo for the ObjectBase class.
template<typename... Args>
static void	connect (Signal< Args... > *signal, Slot< Args... > *slot)
	connects a signal and slot together. This function assumes both the signal and slot exist in a ObjectBase or derived object
Public Attributes inherited from ObjectBase
Signal< ObjectBase * >	aboutToDestroySignal = Signal< ObjectBase * >(this, aboutToDestroySignalName)
Static Public Attributes inherited from ObjectBase
static constexpr const char *	aboutToDestroySignalName = PROMEKI_STRINGIFY( aboutToDestroy ) "(" PROMEKI_STRINGIFY_ARGS( ObjectBase * ) ")"
static SignalMeta	aboutToDestroySignalMeta = SignalMeta(metaInfo(), aboutToDestroySignalName)
Protected Member Functions inherited from ObjectBase
ObjectBase *	signalSender ()
	Returns the ObjectBase that emitted the signal currently being handled.
virtual void	event (Event *e)
	Called by EventLoop to deliver events to this object.
virtual void	timerEvent (TimerEvent *e)
	Called when a timer fires for this object.

Detailed Description

Directed acyclic graph of MediaNodes connected by MediaLinks.

MediaGraph manages the topology of a media processing pipeline. Nodes are added to the graph, then connected via their ports. The graph validates the topology (no cycles, compatible formats, all required ports connected) and provides topological ordering for processing.

An output port may be connected to multiple input ports (fan-out). The same frame is delivered to all connected links.

Constructor & Destructor Documentation

MediaGraph()

MediaGraph::MediaGraph

(

ObjectBase *

parent = nullptr

)

Constructs an empty graph.

Parameters

parent

Optional parent object.

Member Function Documentation

addNode()

Error MediaGraph::addNode

(

MediaNode *

node

)

Adds a node to the graph. Takes ownership.

Parameters

node	The node to add.

Returns

Error::Ok on success.

clear()

void MediaGraph::clear

(

)

Removes all nodes and links.

Deletes all owned nodes.

connect() [1/3]

MediaLink::Ptr MediaGraph::connect	(	MediaNode *	source,
		const String &	outputName,
		MediaNode *	sink,
		const String &	inputName
	)

Connects nodes by port name.

Parameters

source	The source node.
outputName	Output port name on the source node.
sink	The sink node.
inputName	Input port name on the sink node.

Returns

The created link, or a null Ptr on error.

connect() [2/3]

MediaLink::Ptr MediaGraph::connect	(	MediaNode *	source,
		int	outputIndex,
		MediaNode *	sink,
		int	inputIndex
	)

Connects nodes by port index.

Parameters

source	The source node.
outputIndex	Output port index on the source node.
sink	The sink node.
inputIndex	Input port index on the sink node.

Returns

The created link, or a null Ptr on error.

connect() [3/3]

MediaLink::Ptr MediaGraph::connect	(	MediaPort::Ptr	output,
		MediaPort::Ptr	input
	)

Connects an output port to an input port.

Parameters

output	The source output port.
input	The sink input port.

Returns

The created link, or a null Ptr on error.

disconnect() [1/2]

Error MediaGraph::disconnect

(

MediaLink::Ptr

link

)

Disconnects a link.

Parameters

link	The link to disconnect.

Returns

Error::Ok on success.

disconnect() [2/2]

Error MediaGraph::disconnect	(	MediaPort::Ptr	output,
		MediaPort::Ptr	input
	)

Disconnects the link between two specific ports.

Parameters

output	The output port.
input	The input port.

Returns

Error::Ok on success, Error::NotExist if not found.

node()

MediaNode * MediaGraph::node

(

const String &

name

)

const

Finds a node by name.

Parameters

name	The node name.

Returns

The node, or nullptr if not found.

removeNode()

Error MediaGraph::removeNode

(

MediaNode *

node

)

Removes a node from the graph.

Disconnects all links involving this node first. The caller regains ownership and must delete the node.

Parameters

node	The node to remove.

Returns

Error::Ok on success, Error::NotExist if not found.

sinkNodes()

List< MediaNode * > MediaGraph::sinkNodes

(

)

const

Returns nodes with no output connections (sink nodes).

Returns

A list of sink nodes.

sourceNodes()

List< MediaNode * > MediaGraph::sourceNodes

(

)

const

Returns nodes with no input connections (source nodes).

Returns

A list of source nodes.

topologicalSort()

List< MediaNode * > MediaGraph::topologicalSort

(

)

const

Returns nodes in topological order (dependencies first).

Source nodes appear first, sink nodes last.

Returns

An ordered list of node pointers, or empty if the graph has cycles.

validate()

Error MediaGraph::validate

(

)

const

Validates the graph topology.

Checks for cycles (DAG requirement), format compatibility on all links, and that the graph is non-empty.

Returns

Error::Ok if valid, or an error describing the problem.

---

The documentation for this class was generated from the following file:

• include/promeki/proav/mediagraph.h