Base class for all pipeline processing nodes. More...

#include <medianode.h>

Inheritance diagram for MediaNode:

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Collaboration diagram for MediaNode:

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Public Types
enum	State { Idle , Configured , Running , ErrorState }
	Node lifecycle state. More...

enum	ThreadingPolicy { UseGraphPool , DedicatedThread , CustomPool }
	Threading policy for this node. More...

Public Types inherited from ObjectBase
using	SlotVariantFunc = std::function< void(const VariantList &)>
	Function type for invoking a slot with a list of Variants.

Public Member Functions
	MediaNode (ObjectBase *parent=nullptr)
	Constructs a MediaNode.

virtual	~MediaNode ()
	Virtual destructor.

State	state () const
	Returns the current state.

const String &	name () const
	Returns the node name.

void	setName (const String &name)
	Sets the node name.

const MediaPort::PtrList &	inputPorts () const
	Returns the list of input ports.

const MediaPort::PtrList &	outputPorts () const
	Returns the list of output ports.

MediaPort::Ptr	inputPort (int index) const
	Returns the input port at the given index.

MediaPort::Ptr	outputPort (int index) const
	Returns the output port at the given index.

MediaPort::Ptr	inputPort (const String &name) const
	Returns the input port with the given name.

MediaPort::Ptr	outputPort (const String &name) const
	Returns the output port with the given name.

int	inputPortCount () const
	Returns the number of input ports.

int	outputPortCount () const
	Returns the number of output ports.

void	setThreadingPolicy (ThreadingPolicy policy)
	Sets the threading policy.

void	setThreadingPolicy (ThreadPool *pool)
	Sets a custom thread pool and switches policy to CustomPool.

ThreadingPolicy	threadingPolicy () const
	Returns the current threading policy.

ThreadPool *	customThreadPool () const
	Returns the custom thread pool, or nullptr if not using CustomPool.

void	setIdealQueueSize (int size)
	Sets the ideal input queue depth.

int	idealQueueSize () const
	Returns the ideal input queue size.

int	queuedFrameCount () const
	Returns the current input queue depth.

virtual Error	configure ()
	Validates ports and allocates resources.

virtual Error	start ()
	Begins processing.

virtual void	stop ()
	Stops processing.

virtual void	process ()=0
	Processes one cycle of data.

virtual void	starvation ()
	Called when the node's input queue is empty and data is needed.

virtual Map< String, Variant >	properties () const
	Returns all configurable properties as key-value pairs.

virtual Error	setProperty (const String &name, const Variant &value)
	Sets a property by name.

Variant	property (const String &name) const
	Gets a single property value by name.

NodeStats	stats () const
	Returns a snapshot of the node's performance statistics.

void	resetStats ()
	Resets all statistics counters to zero.

virtual Map< String, Variant >	extendedStats () const
	Returns additional node-specific statistics.

	PROMEKI_SIGNAL (stateChanged, State)
	Emitted when the node's state changes.

	PROMEKI_SIGNAL (errorOccurred, Error)
	Emitted when an error occurs.

	PROMEKI_SIGNAL (messageEmitted, NodeMessage)
	Emitted when the node produces a message.

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)

Static Public Member Functions
static void	registerNodeType (const String &typeName, std::function< MediaNode *()> factory)
	Registers a node type for runtime creation.

static MediaNode *	createNode (const String &typeName)
	Creates a node by registered type name.

static List< String >	registeredNodeTypes ()
	Returns the list of all registered node type names.

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

Protected Member Functions
void	enqueueInput (Frame::Ptr frame)
	Enqueues a frame into this node's input queue.

void	recordProcessTiming (double duration)
	Records timing for a process() call.

void	recordStarvation ()
	Records a starvation event.

void	addInputPort (MediaPort::Ptr port)
	Adds an input port to this node.

void	addOutputPort (MediaPort::Ptr port)
	Adds an output port to this node.

void	setState (State state)
	Sets the node state and emits stateChanged.

Frame::Ptr	dequeueInput ()
	Dequeues a frame from this node's input queue.

void	deliverOutput (int portIndex, Frame::Ptr frame)
	Delivers a frame to all outgoing links on the given output port.

void	deliverOutput (Frame::Ptr frame)
	Delivers a frame to all outgoing links on all output ports.

void	emitMessage (Severity severity, const String &message, uint64_t frameNumber=0)
	Emits a message with the given severity and text.

void	emitWarning (const String &message)
	Emits a Warning-severity message.

void	emitError (const String &message)
	Emits an Error-severity message.

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.

Friends
class	MediaGraph

class	MediaLink

class	MediaPipeline

Additional Inherited Members
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)

Detailed Description

Base class for all pipeline processing nodes.

MediaNode is the ObjectBase-derived base class for all processing nodes in the media pipeline framework. It manages input and output ports, lifecycle state transitions, threading policy, and provides a uniform property interface for future JSON serialization.

Concrete node subclasses override the virtual lifecycle methods (configure, start, stop, process, starvation) to implement their specific processing logic.

Member Enumeration Documentation

◆ State

enum MediaNode::State

Node lifecycle state.

Enumerator
Idle	Initial state, not configured.
Configured	Configured and ready to start.
Running	Actively processing data.
ErrorState	An error has occurred.

◆ ThreadingPolicy

enum MediaNode::ThreadingPolicy

Threading policy for this node.

Enumerator
UseGraphPool	Use the graph's default thread pool.
DedicatedThread	Run on a dedicated thread.
CustomPool	Use a custom thread pool.

Constructor & Destructor Documentation

◆ MediaNode()

MediaNode::MediaNode ( ObjectBase * parent = nullptr )

Constructs a MediaNode.

Parameters

parent Optional parent object.

Member Function Documentation

◆ addInputPort()

void MediaNode::addInputPort ( MediaPort::Ptr port )

protected

Adds an input port to this node.

Parameters

port	The port to add.

◆ addOutputPort()

void MediaNode::addOutputPort ( MediaPort::Ptr port )

protected

Adds an output port to this node.

Parameters

port	The port to add.

◆ configure()

virtual Error MediaNode::configure ( )

virtual

Validates ports and allocates resources.

Transitions the node from Idle to Configured on success.

Returns: Error::Ok on success, or an error code.

Reimplemented in FrameDemuxNode, JpegEncoderNode, RtpAudioSinkNode, RtpVideoSinkNode, TestPatternNode, and TimecodeOverlayNode.

◆ createNode()

static MediaNode * MediaNode::createNode ( const String & typeName )

static

Creates a node by registered type name.

Parameters

typeName The type name to instantiate.

Returns: A new node instance, or nullptr if the type is not registered.

◆ deliverOutput() [1/2]

void MediaNode::deliverOutput ( Frame::Ptr frame )

protected

Delivers a frame to all outgoing links on all output ports.

Convenience for single-output nodes.

Parameters

frame The frame to deliver.

◆ deliverOutput() [2/2]

void MediaNode::deliverOutput	(	int	portIndex,
		Frame::Ptr	frame
	)

protected

Delivers a frame to all outgoing links on the given output port.

Source nodes call this from process() to push frames downstream.

Parameters

portIndex	The output port index.
frame	The frame to deliver.

◆ dequeueInput()

Frame::Ptr MediaNode::dequeueInput ( )

protected

Dequeues a frame from this node's input queue.

Returns a null Ptr if the queue is empty. Subclasses call this from process() to pull input frames.

Returns: The next frame, or a null Ptr if the queue is empty.

◆ emitError()

void MediaNode::emitError ( const String & message )

protected

Emits an Error-severity message.

Also transitions the node to ErrorState and emits errorOccurred.

Parameters

message The error text.

◆ emitMessage()

void MediaNode::emitMessage	(	Severity	severity,
		const String &	message,
		uint64_t	frameNumber = `0`
	)

protected

Emits a message with the given severity and text.

Auto-populates timestamp and node pointer. Subclasses call this to report events during processing.

Parameters

severity	The message severity.
message	The message text.
frameNumber	The frame number this relates to (0 if not frame-specific).

◆ emitWarning()

void MediaNode::emitWarning ( const String & message )

protected

Emits a Warning-severity message.

Parameters

message The warning text.

◆ enqueueInput()

void MediaNode::enqueueInput ( Frame::Ptr frame )

protected

Enqueues a frame into this node's input queue.

Called by the pipeline to deliver frames from upstream nodes.

Parameters

frame The frame to enqueue.

◆ extendedStats()

virtual Map< String, Variant > MediaNode::extendedStats ( ) const

virtual

Returns additional node-specific statistics.

Override in concrete nodes to expose custom statistics (e.g., "packetsSent", "bytesSent" for RTP nodes).

Returns: A map of stat names to Variant values.

Reimplemented in JpegEncoderNode, RtpAudioSinkNode, RtpVideoSinkNode, and TestPatternNode.

◆ inputPort() [1/2]

MediaPort::Ptr MediaNode::inputPort ( const String & name ) const

Returns the input port with the given name.

Parameters

name	The port name.

Returns: The port, or a null Ptr if not found.

◆ inputPort() [2/2]

MediaPort::Ptr MediaNode::inputPort ( int index ) const

Returns the input port at the given index.

Parameters

index Zero-based port index.

Returns: The port, or a null Ptr if the index is out of range.

◆ outputPort() [1/2]

MediaPort::Ptr MediaNode::outputPort ( const String & name ) const

Returns the output port with the given name.

Parameters

name	The port name.

Returns: The port, or a null Ptr if not found.

◆ outputPort() [2/2]

MediaPort::Ptr MediaNode::outputPort ( int index ) const

Returns the output port at the given index.

Parameters

index Zero-based port index.

Returns: The port, or a null Ptr if the index is out of range.

◆ process()

virtual void MediaNode::process ( )

pure virtual

Processes one cycle of data.

Pure virtual — must be implemented by concrete node subclasses.

Implemented in FrameDemuxNode, JpegEncoderNode, RtpAudioSinkNode, RtpVideoSinkNode, TestPatternNode, and TimecodeOverlayNode.

◆ properties()

virtual Map< String, Variant > MediaNode::properties ( ) const

virtual

Returns all configurable properties as key-value pairs.

Concrete nodes override this to expose their configuration.

Returns: A map of property names to Variant values.

◆ property()

Variant MediaNode::property ( const String & name ) const

Gets a single property value by name.

Parameters

name	The property name.

Returns: The property value, or an invalid Variant if not found.

◆ recordProcessTiming()

void MediaNode::recordProcessTiming ( double duration )

protected

Records timing for a process() call.

Called by the pipeline to instrument process() with timing. Updates processCount, lastProcessDuration, avgProcessDuration, and peakProcessDuration.

Parameters

duration The wall-clock duration of the process() call in seconds.

◆ recordStarvation()

void MediaNode::recordStarvation ( )

protected

Records a starvation event.

Called by the pipeline when starvation() is invoked. Increments starvationCount.

◆ registeredNodeTypes()

static List< String > MediaNode::registeredNodeTypes ( )

static

Returns the list of all registered node type names.

Returns: A list of type name strings.

◆ registerNodeType()

static void MediaNode::registerNodeType	(	const String &	typeName,
		std::function< MediaNode *()>	factory
	)

static

Registers a node type for runtime creation.

Parameters

typeName	The unique type name string.
factory	A factory function that creates a new instance.

◆ setIdealQueueSize()

void MediaNode::setIdealQueueSize ( int size )

inline

Sets the ideal input queue depth.

The pipeline uses this as a hint for back-pressure.

Parameters

size	Target queue depth (default: 2).

◆ setName()

void MediaNode::setName ( const String & name )

inline

Sets the node name.

Parameters

name	The human-readable node name.

◆ setProperty()

virtual Error MediaNode::setProperty	(	const String &	name,
		const Variant &	value
	)

virtual

Sets a property by name.

Parameters

name	The property name.
value	The value to set.

Returns: Error::Ok on success, or an error (e.g. unknown property, type mismatch).

◆ setState()

void MediaNode::setState ( State state )

protected

Sets the node state and emits stateChanged.

Parameters

state The new state.

◆ setThreadingPolicy() [1/2]

void MediaNode::setThreadingPolicy ( ThreadingPolicy policy )

inline

Sets the threading policy.

Parameters

policy The threading policy to use.

◆ setThreadingPolicy() [2/2]

void MediaNode::setThreadingPolicy ( ThreadPool * pool )

inline

Sets a custom thread pool and switches policy to CustomPool.

Parameters

pool	The custom thread pool.

◆ start()

virtual Error MediaNode::start ( )

virtual

Begins processing.

Transitions the node from Configured to Running on success.

Returns: Error::Ok on success, or an error code.

Reimplemented in RtpAudioSinkNode, RtpVideoSinkNode, and TestPatternNode.

◆ starvation()

virtual void MediaNode::starvation ( )

virtual

Called when the node's input queue is empty and data is needed.

Override for nodes that need to handle starvation (e.g. log, insert silence/black, repeat last frame). Default: no-op.

Reimplemented in RtpAudioSinkNode, and RtpVideoSinkNode.

◆ stats()

NodeStats MediaNode::stats ( ) const

Returns a snapshot of the node's performance statistics.

Returns: The current NodeStats.

◆ stop()

virtual void MediaNode::stop ( )

virtual

Stops processing.

Transitions the node from Running to Idle.

Reimplemented in RtpAudioSinkNode, RtpVideoSinkNode, and TestPatternNode.

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

include/promeki/proav/medianode.h

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Friends

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ State

◆ ThreadingPolicy

Constructor & Destructor Documentation

◆ MediaNode()

Member Function Documentation

◆ addInputPort()

◆ addOutputPort()

◆ configure()

◆ createNode()

◆ deliverOutput() [1/2]

◆ deliverOutput() [2/2]

◆ dequeueInput()

◆ emitError()

◆ emitMessage()

◆ emitWarning()

◆ enqueueInput()

◆ extendedStats()

◆ inputPort() [1/2]

◆ inputPort() [2/2]

◆ outputPort() [1/2]

◆ outputPort() [2/2]

◆ process()

◆ properties()

◆ property()

◆ recordProcessTiming()

◆ recordStarvation()

◆ registeredNodeTypes()

◆ registerNodeType()

◆ setIdealQueueSize()

◆ setName()

◆ setProperty()

◆ setState()

◆ setThreadingPolicy() [1/2]

◆ setThreadingPolicy() [2/2]

◆ start()

◆ starvation()

◆ stats()

◆ stop()