#include <qsyntheticpipewirevideosource_p.h>

Collaboration diagram for QSyntheticPipeWireVideoSource:

Classes
class	Private

Public Member Functions
	QSyntheticPipeWireVideoSource ()
	~QSyntheticPipeWireVideoSource ()
q23::expected< void, QString >	start (const SyntheticVideoScene &scene, const QSyntheticPipeWireVideoSourceConfig &config=QSyntheticPipeWireVideoSourceConfig::screenCast())
	Connects to the PipeWire daemon and publishes the source.
void	stop ()
QtPipeWire::ObjectId	nodeId () const
	The PipeWire node id to hand to a consumer. Valid only after a successful start().
void	setScene (const SyntheticVideoScene &scene)
	Replaces the published content. Safe to call from any thread.
void	renderNextFrame ()
	Renders and publishes the next frame. Safe to call from any thread.

Detailed Description

A synthetic PipeWire video source: an output pw_stream advertising {media.class = Stream/Output/Video} that publishes frames rendered by paintSyntheticVideoScene(). It stands in for a compositor's screen-cast stream, so QPipeWireCaptureHelper can be exercised without a real desktop portal.

The pixel format is fixed to SPA_VIDEO_FORMAT_BGRx, which maps to QVideoFrameFormat::Format_BGRX8888 on the consuming side and is byte-identical to QImage::Format_RGB32 on little-endian, avoiding a pixel format conversion.

The source also acts as its own session manager: when it is used against a private pipewire daemon there is no WirePlumber, so nothing honours PW_STREAM_FLAG_AUTOCONNECT and the consumer would sit in "paused" forever. The source therefore links itself, via the link-factory, to consumers meant for it.

Which consumers are "meant for it" is determined by matching media.role, not by the target passed to pw_stream_connect(): PipeWire consumes that target internally, and the resulting consumer node advertises neither target.object nor node.target. media.role is the one property a consumer does advertise – QPipeWireCaptureHelper sets Screen, a camera client sets Camera – so the source links only consumer nodes whose media.role matches its own. This matters as soon as one graph holds both a screen-cast and a camera source: matching by media.role is what keeps camera frames from being linked to a screen-capture client.

Definition at line 85 of file qsyntheticpipewirevideosource_p.h.

Constructor & Destructor Documentation

◆ QSyntheticPipeWireVideoSource()

QSyntheticPipeWireVideoSource::QSyntheticPipeWireVideoSource ( )

Definition at line 299 of file qsyntheticpipewirevideosource.cpp.

◆ ~QSyntheticPipeWireVideoSource()

QSyntheticPipeWireVideoSource::~QSyntheticPipeWireVideoSource ( )

Definition at line 301 of file qsyntheticpipewirevideosource.cpp.

References stop().

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Member Function Documentation

◆ nodeId()

QtPipeWire::ObjectId QSyntheticPipeWireVideoSource::nodeId ( ) const

nodiscard

The PipeWire node id to hand to a consumer. Valid only after a successful start().

Definition at line 438 of file qsyntheticpipewirevideosource.cpp.

◆ renderNextFrame()

void QSyntheticPipeWireVideoSource::renderNextFrame ( )

Renders and publishes the next frame. Safe to call from any thread.

Definition at line 451 of file qsyntheticpipewirevideosource.cpp.

◆ setScene()

void QSyntheticPipeWireVideoSource::setScene ( const SyntheticVideoScene & scene )

Replaces the published content. Safe to call from any thread.

Definition at line 443 of file qsyntheticpipewirevideosource.cpp.

◆ start()

q23::expected< void, QString > QSyntheticPipeWireVideoSource::start	(	const SyntheticVideoScene &	scene,
		const QSyntheticPipeWireVideoSourceConfig &	config = QSyntheticPipeWireVideoSourceConfig::screenCast() )