The V4L2 M2M converter implements the converter interface based on V4L2 M2M device. More...

Inheritance diagram for libcamera::V4L2M2MConverter:

Collaboration diagram for libcamera::V4L2M2MConverter:

Public Member Functions
	V4L2M2MConverter (MediaDevice *media)
	Construct a V4L2M2MConverter instance. More...

int	loadConfiguration ([[maybe_unused]] const std::string &filename)

bool	isValid () const

std::vector< PixelFormat >	formats (PixelFormat input)

SizeRange	sizes (const Size &input)
	Retrieve the range of minimum and maximum output sizes for an input size. More...

std::tuple< unsigned int, unsigned int >	strideAndFrameSize (const PixelFormat &pixelFormat, const Size &size)
	Retrieve the output stride and frame size for an input configutation. More...

int	configure (const StreamConfiguration &inputCfg, const std::vector< std::reference_wrapper< StreamConfiguration >> &outputCfg)
	Configure a set of output stream conversion from an input stream. More...

int	exportBuffers (unsigned int output, unsigned int count, std::vector< std::unique_ptr< FrameBuffer >> *buffers)
	Export buffers from the converter device. More...

int	start ()
	Start the converter streaming operation. More...

void	stop ()
	Stop the converter streaming operation. More...

int	queueBuffers (FrameBuffer input, const std::map< unsigned int, FrameBuffer > &outputs)
	Queue buffers to converter device. More...

Public Member Functions inherited from libcamera::Converter
	Converter (MediaDevice *media)
	Construct a Converter instance. More...

virtual int	loadConfiguration (const std::string &filename)=0
	Load converter configuration from file. More...

const std::string &	deviceNode () const
	The converter device node attribute accessor. More...

Additional Inherited Members
Public Attributes inherited from libcamera::Converter
Signal< FrameBuffer * >	inputBufferReady
	A signal emitted when the input frame buffer completes.

Signal< FrameBuffer * >	outputBufferReady
	A signal emitted on each frame buffer completion of the output queue.

Detailed Description

The V4L2 M2M converter implements the converter interface based on V4L2 M2M device.

Constructor & Destructor Documentation

◆ V4L2M2MConverter()

libcamera::V4L2M2MConverter::V4L2M2MConverter ( MediaDevice * media )

Construct a V4L2M2MConverter instance.

Parameters

[in] media The media device implementing the converter

Member Function Documentation

◆ configure()

int libcamera::V4L2M2MConverter::configure	(	const StreamConfiguration &	inputCfg,
		const std::vector< std::reference_wrapper< StreamConfiguration >> &	outputCfgs
	)

virtual

Configure a set of output stream conversion from an input stream.

Parameters

[in]	inputCfg	Input stream configuration
[out]	outputCfgs	A list of output stream configurations

Returns: 0 on success or a negative error code otherwise

Implements libcamera::Converter.

◆ exportBuffers()

int libcamera::V4L2M2MConverter::exportBuffers	(	unsigned int	output,
		unsigned int	count,
		std::vector< std::unique_ptr< FrameBuffer >> *	buffers
	)

virtual

Export buffers from the converter device.

Parameters

[in]	output	Output stream index exporting the buffers
[in]	count	Number of buffers to allocate
[out]	buffers	Vector to store allocated buffers

This function operates similarly to V4L2VideoDevice::exportBuffers() on the output stream indicated by the output index.

Returns: The number of allocated buffers on success or a negative error code otherwise

Implements libcamera::Converter.

◆ formats()

std::vector< PixelFormat > libcamera::V4L2M2MConverter::formats ( PixelFormat input )

virtual

Parameters

[in] input Input pixel format to retrieve output pixel format list for

Returns: The list of supported output pixel formats

Implements libcamera::Converter.

◆ isValid()

libcamera::V4L2M2MConverter::isValid ( ) const

inlinevirtual

Returns: True is the converter is valid, false otherwise

Implements libcamera::Converter.

◆ loadConfiguration()

libcamera::V4L2M2MConverter::loadConfiguration ( [[maybe_unused] ] const std::string & filename )

inline

Parameters

[in] filename The file name path

Load converter dependent configuration parameters to apply on the hardware.

Returns: 0 on success or a negative error code otherwise

◆ queueBuffers()

int libcamera::V4L2M2MConverter::queueBuffers	(	FrameBuffer *	input,
		const std::map< unsigned int, FrameBuffer *> &	outputs
	)

virtual

Queue buffers to converter device.

Parameters

[in]	input	The frame buffer to apply the conversion
[out]	outputs	The container holding the output stream indexes and their respective frame buffer outputs.

This function queues the input frame buffer on the output streams of the outputs map key and retrieve the output frame buffer indicated by the buffer map value.

Returns: 0 on success or a negative error code otherwise

Implements libcamera::Converter.

◆ sizes()

SizeRange libcamera::V4L2M2MConverter::sizes ( const Size & input )

virtual

Retrieve the range of minimum and maximum output sizes for an input size.

Parameters

[in] input Input stream size to retrieve range for

Returns: A range of output image sizes

Implements libcamera::Converter.

◆ start()

int libcamera::V4L2M2MConverter::start ( )

virtual

Start the converter streaming operation.

Returns: 0 on success or a negative error code otherwise

Implements libcamera::Converter.

◆ stop()

void libcamera::V4L2M2MConverter::stop ( )

virtual

Stop the converter streaming operation.

Implements libcamera::Converter.

◆ strideAndFrameSize()

std::tuple< unsigned int, unsigned int > libcamera::V4L2M2MConverter::strideAndFrameSize	(	const PixelFormat &	pixelFormat,
		const Size &	size
	)

virtual

Retrieve the output stride and frame size for an input configutation.

Parameters

[in]	pixelFormat	Input stream pixel format
[in]	size	Input stream size

Returns: A tuple indicating the stride and frame size or an empty tuple on error

Implements libcamera::Converter.

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

include/libcamera/internal/converter/converter_v4l2_m2m.h
src/libcamera/converter/converter_v4l2_m2m.cpp

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ V4L2M2MConverter()

Member Function Documentation

◆ configure()

◆ exportBuffers()

◆ formats()

◆ isValid()

◆ loadConfiguration()

◆ queueBuffers()

◆ sizes()

◆ start()

◆ stop()

◆ strideAndFrameSize()