Abstract base class for QueueSink notifications. More...

Public Member Functions
virtual bool	sinkConnected (QueueSink &sink, const ImageType &imageType, size_t min_buffers_required)
	Called when the data stream to the sink is created.

virtual void	sinkDisconnected (QueueSink &sink)
	Called when the data stream to the sink is stopped.

virtual void	framesQueued (QueueSink &sink)=0
	Called when new images were added to the sink's queue of filled buffers.

Detailed Description

Abstract base class for QueueSink notifications.

Member Function Documentation

virtual void framesQueued ( QueueSink & sink )

pure virtual

Called when new images were added to the sink's queue of filled buffers.

This callback usually calls QueueSink::popOutputBuffer() to access the filled image buffers.

Parameters

[in] sink The sink object

Note: If this callback function performs a lengthy operation, it is recommended to regularly check QueueSink::isCancelRequested() to determine whether the data stream is being stopped.; The function is executed on dedicated thread managed by the sink.

Warning: When the data stream to the sink is stopped, the Grabber::streamStop() call wait until this function returns. This can quickly lead to a deadlock, if code in the framesQueued callback performs an operation that unconditionally requires activity on the thread that called Grabber::streamStop().

inlinevirtual

Called when the data stream to the sink is created.

Parameters

[in]	sink	The sink object
[in]	imageType	The negotiated image type that the sink will receive
[in]	min_buffers_required	The minimum number of buffers required by the device to start a stream

Returns: true, if the data stream should be created. If false is returned the call to Grabber::streamSetup() will fail.

Note: The function is executed on the thread that calls Grabber::streamSetup().; If the callback function does not allocate any buffers, the sink will automatically allocate the minimum number of buffers required.

virtual void sinkDisconnected ( QueueSink & sink )

inlinevirtual

Called when the data stream to the sink is stopped.

Parameters

[in] sink The sink object

Note: The function is executed on the thread that calls Grabber::streamStop().