This class defines a video input device. More...

#include <videoio.h>

Inheritance diagram for PVideoInputDevice:

Classes
struct	Capabilities

Public Member Functions
	~PVideoInputDevice ()
	Create a new video input device. More...

virtual bool	GetDeviceCapabilities (Capabilities *capabilities) const
	Retrieve a list of Device Capabilities. More...

virtual PVideoInputControl *	GetVideoInputControls ()
	Get the devices video Input controls By Default return NULL;. More...

virtual PBoolean	Open (const PString &deviceName, PBoolean startImmediate=true)=0
	Open the device given the device name. More...

virtual PBoolean	Close ()
	Close the device. More...

virtual PBoolean	CanCaptureVideo () const
	Is the device a camera, and obtain video. More...

virtual PBoolean	IsCapturing ()=0
	Determine if the video device I/O capture is in progress. More...

virtual PBoolean	SetNearestFrameSize (unsigned width, unsigned height)
	Set the nearest available frame size to be used. More...

virtual PBoolean	GetFrame (PBYTEArray &frame)
	Grab a frame. More...

virtual PBoolean	GetFrameData (BYTE buffer, PINDEX bytesReturned, unsigned int &flags)
	Grab a frame, after a delay as specified by the frame rate. More...

virtual PBoolean	GetFrameData (BYTE buffer, PINDEX bytesReturned=NULL)=0

virtual PBoolean	GetFrameDataNoDelay (BYTE buffer, PINDEX bytesReturned, unsigned int &flags)
	Grab a frame. More...

virtual PBoolean	GetFrameDataNoDelay (BYTE buffer, PINDEX bytesReturned=NULL)=0

virtual bool	FlowControl (const void *flowData)
	Pass data to the inputdevice for flowControl determination. More...

virtual bool	SetCaptureMode (unsigned mode)
	Set the capture modes for implementations that support them. More...

virtual int	GetCaptureMode () const
	Returns the current capture mode. More...

Public Member Functions inherited from PVideoDevice
virtual	~PVideoDevice ()
	Delete structures created by PVideoDevice();. More...

const PString &	GetDeviceName () const
	Get the device name of the open device. More...

virtual PStringArray	GetDeviceNames () const =0
	Get a list of all of the drivers available. More...

virtual PBoolean	OpenFull (const OpenArgs &args, PBoolean startImmediate=true)
	Open the device given the device name. More...

virtual PBoolean	IsOpen ()=0
	Determine if the device is currently open. More...

virtual PBoolean	Start ()=0
	Start the video device I/O capture. More...

virtual PBoolean	Stop ()=0
	Stop the video device I/O capture. More...

virtual PBoolean	SetVideoFormat (VideoFormat videoFormat)
	Set the video format to be used. More...

virtual VideoFormat	GetVideoFormat () const
	Get the video format being used. More...

virtual int	GetNumChannels ()
	Get the number of video channels available on the device. More...

virtual PBoolean	SetChannel (int channelNumber)
	Set the video channel to be used on the device. More...

virtual int	GetChannel () const
	Get the video channel to be used on the device. More...

virtual PBoolean	SetColourFormatConverter (const PString &colourFormat)
	Set the colour format to be used, trying converters if available. More...

virtual PBoolean	GetVFlipState ()
	Get the video conversion vertical flip state. More...

virtual PBoolean	SetVFlipState (PBoolean newVFlipState)
	Set the video conversion vertical flip state. More...

virtual PBoolean	GetFrameSizeLimits (unsigned &minWidth, unsigned &minHeight, unsigned &maxWidth, unsigned &maxHeight)
	Get the minimum & maximum size of a frame on the device. More...

virtual PBoolean	SetFrameSizeConverter (unsigned width, unsigned height, ResizeMode resizeMode=eMaxResizeMode)
	Set the frame size to be used, trying converters if available. More...

virtual PBoolean	SetFrameSizeConverter (unsigned width, unsigned height, PBoolean)
	Set the frame size to be used, trying converters if available. More...

virtual PBoolean	SetFrameSize (unsigned width, unsigned height)
	Set the frame size to be used. More...

virtual PBoolean	GetFrameSize (unsigned &width, unsigned &height) const
	Get the frame size being used. More...

virtual PINDEX	GetMaxFrameBytes ()=0
	Get the maximum frame size in bytes. More...

int	GetLastError () const
	Get the last error code. More...

virtual int	GetBrightness ()
	Get the brightness of the image. More...

virtual PBoolean	SetBrightness (unsigned newBrightness)
	Set brightness of the image. More...

virtual int	GetWhiteness ()
	Get the whiteness of the image. More...

virtual PBoolean	SetWhiteness (unsigned newWhiteness)
	Set whiteness of the image. More...

virtual int	GetColour ()
	Get the colour of the image. More...

virtual PBoolean	SetColour (unsigned newColour)
	Set colour of the image. More...

virtual int	GetContrast ()
	Get the contrast of the image. More...

virtual PBoolean	SetContrast (unsigned newContrast)
	Set contrast of the image. More...

virtual int	GetHue ()
	Get the hue of the image. More...

virtual PBoolean	SetHue (unsigned newHue)
	Set hue of the image. More...

virtual PBoolean	GetParameters (int whiteness, int brightness, int colour, int contrast, int *hue)
	Return whiteness, brightness, colour, contrast and hue in one call. More...

virtual PBoolean	SetVideoChannelFormat (int channelNumber, VideoFormat videoFormat)
	Set VideoFormat and VideoChannel in one ioctl. More...

void	SetPreferredColourFormat (const PString &colourFmt)
	Set preferred native colour format from video capture device. More...

const PString &	GetPreferredColourFormat ()
	Get preferred native colour format from video capture device. More...

Public Member Functions inherited from PVideoFrameInfo
	PVideoFrameInfo ()
	Construct video frame information. More...

	PVideoFrameInfo (unsigned frameWidth, unsigned frameHeight, const PString &colourFormat="YUV420P", unsigned frameRate=15, ResizeMode resizeMode=eScale)

virtual Comparison	Compare (const PObject &obj) const
	Compare the two PVideoFrameInfo and return their relative rank. More...

virtual void	PrintOn (ostream &strm) const
	Output the contents of the object to the stream. More...

virtual unsigned	GetFrameWidth () const
	Get the width of the frame being used. More...

virtual unsigned	GetFrameHeight () const
	Get the height of the frame being used. More...

virtual PBoolean	SetFrameSar (unsigned width, unsigned height)
	Set the sar size to be used. More...

virtual PBoolean	GetSarSize (unsigned &width, unsigned &height) const
	Get the sar size being used. More...

virtual unsigned	GetSarWidth () const
	Get the width of the sar being used. More...

virtual unsigned	GetSarHeight () const
	Get the height of the sar being used. More...

virtual PBoolean	SetFrameRate (unsigned rate)
	Set the video frame rate to be used on the device. More...

virtual unsigned	GetFrameRate () const
	Get the video frame rate used on the device. More...

virtual PBoolean	SetColourFormat (const PString &colourFormat)
	Set the colour format to be used. More...

virtual const PString &	GetColourFormat () const
	Get the colour format to be used. More...

void	SetResizeMode (ResizeMode mode)
	Set the resize mode to be used. More...

ResizeMode	GetResizeMode () const
	Get the resize mode to be used. More...

PINDEX	CalculateFrameBytes () const
	Get the number of bytes of an image, given a particular width, height and colour format. More...

bool	Parse (const PString &str)
	Parse a descriptor string for the video format. More...

Public Member Functions inherited from PObject
virtual	~PObject ()

virtual PObject *	Clone () const
	Create a copy of the class on the heap. More...

virtual PINDEX	HashFunction () const
	This function yields a hash value required by the `PDictionary` class. More...

virtual const char *	GetClass (unsigned ancestor=0) const
	Get the current dynamic type of the object instance. More...

PBoolean	IsClass (const char *cls) const

virtual PBoolean	InternalIsDescendant (const char *clsName) const
	Determine if the dynamic type of the current instance is a descendent of the specified class. More...

virtual Comparison	CompareObjectMemoryDirect (const PObject &obj) const
	Determine the byte wise comparison of two objects. More...

bool	operator== (const PObject &obj) const
	Compare the two objects. More...

bool	operator!= (const PObject &obj) const
	Compare the two objects. More...

bool	operator< (const PObject &obj) const
	Compare the two objects. More...

bool	operator> (const PObject &obj) const
	Compare the two objects. More...

bool	operator<= (const PObject &obj) const
	Compare the two objects. More...

bool	operator>= (const PObject &obj) const
	Compare the two objects. More...

virtual void	ReadFrom (istream &strm)
	Input the contents of the object from the stream. More...

Static Public Member Functions
static PStringArray	GetDriverNames (PPluginManager *pluginMgr=NULL)
	Get the list of available video input drivers (plug-ins) More...

static PStringArray	GetDriversDeviceNames (const PString &driverName, PPluginManager *pluginMgr=NULL)
	Get video input devices that correspond to the specified driver name. More...

static PVideoInputDevice *	CreateDevice (const PString &driverName, PPluginManager *pluginMgr=NULL)
	Create the video input device that corresponds to the specified driver name. More...

static PVideoInputDevice *	CreateDeviceByName (const PString &deviceName, const PString &driverName=PString::Empty(), PPluginManager *pluginMgr=NULL)

static PVideoInputDevice *	CreateOpenedDevice (const PString &driverName, const PString &deviceName, PBoolean startImmediate=true, PPluginManager *pluginMgr=NULL)
	Create an opened video input device that corresponds to the specified names. More...

static PVideoInputDevice *	CreateOpenedDevice (const OpenArgs &args, PBoolean startImmediate=true)
	Create an opened video output device that corresponds to the specified arguments. More...

static PBoolean	GetDeviceCapabilities (const PString &deviceName, Capabilities capabilities, PPluginManager pluginMgr=NULL)
	Retrieve a list of Device Capabilities for particular device. More...

static PBoolean	GetDeviceCapabilities (const PString &deviceName, const PString &driverName, Capabilities caps, PPluginManager pluginMgr=NULL)
	Retrieve a list of Device Capabilities for a particular driver. More...

Static Public Member Functions inherited from PVideoFrameInfo
static PINDEX	CalculateFrameBytes (unsigned width, unsigned height, const PString &colourFormat)

static bool	ParseSize (const PString &str, unsigned &width, unsigned &height)
	Parse the standard size string names. More...

static PString	AsString (unsigned width, unsigned height)
	Get a width/height as a standard size string name. More...

static PStringArray	GetSizeNames ()
	Get all "known" image size names. More...

Static Public Member Functions inherited from PObject
static const char *	Class ()
	Get the name of the class as a C string. More...

static Comparison	InternalCompareObjectMemoryDirect (const PObject obj1, const PObject obj2, PINDEX size)
	Internal function caled from CompareObjectMemoryDirect() More...

Additional Inherited Members
Public Types inherited from PVideoDevice
enum	VideoFormat { PAL, NTSC, SECAM, Auto, NumVideoFormats }

Public Types inherited from PVideoFrameInfo
enum	ResizeMode { eScale, eCropCentre, eCropTopLeft, eMaxResizeMode }

enum	StandardSizes { SQCIFWidth = 128, SQCIFHeight = 96, QCIFWidth = 176, QCIFHeight = 144, CIFWidth = 352, CIFHeight = 288, CIF4Width = 704, CIF4Height = 576, CIF16Width = 1408, CIF16Height = 1152, HD480Width = 704, HD480Height = 480, i480Width = 704, i480Height = 480, HD720Width = 1280, HD720Height = 720, p720Width = 1280, p720Height = 720, HD1080Width = 1920, HD1080Height = 1080, i1080Width = 1920, i1080Height = 1080, HDTVWidth = 1920, HDTVHeight = 1080, MaxWidth = 1920, MaxHeight = 1200 }

Public Types inherited from PObject
enum	Comparison { LessThan = -1, EqualTo = 0, GreaterThan = 1 }
	Result of the comparison operation performed by the `Compare()` function. More...

Protected Member Functions inherited from PVideoDevice
	PVideoDevice ()
	Create a new video device (input or output). More...

PINDEX	GetMaxFrameBytesConverted (PINDEX rawFrameBytes) const

Protected Member Functions inherited from PObject
	PObject ()
	Constructor for PObject, made protected so cannot ever create one on its own. More...

Protected Attributes inherited from PVideoDevice
PString	deviceName

int	lastError

VideoFormat	videoFormat

int	channelNumber

PString	preferredColourFormat

PBoolean	nativeVerticalFlip

PColourConverter *	converter

PBYTEArray	frameStore

int	frameBrightness

int	frameWhiteness

int	frameContrast

int	frameColour

int	frameHue

Protected Attributes inherited from PVideoFrameInfo
unsigned	frameWidth

unsigned	frameHeight

unsigned	sarWidth

unsigned	sarHeight

unsigned	frameRate

PString	colourFormat

ResizeMode	resizeMode

Detailed Description

This class defines a video input device.

Constructor & Destructor Documentation

§ ~PVideoInputDevice()

PVideoInputDevice::~PVideoInputDevice ( )

inline

Create a new video input device.

Close the video input device on destruction.

References PString::Empty().

Member Function Documentation

§ CanCaptureVideo()

virtual PBoolean PVideoInputDevice::CanCaptureVideo ( ) const

virtual

Is the device a camera, and obtain video.

Implements PVideoDevice.

§ Close()

virtual PBoolean PVideoInputDevice::Close ( )

inlinevirtual

Close the device.

Implements PVideoDevice.

Reimplemented in PVideoInput1394DcDevice.

§ CreateDevice()

static PVideoInputDevice* PVideoInputDevice::CreateDevice	(	const PString &	driverName,
		PPluginManager *	pluginMgr = `NULL`
	)

static

Create the video input device that corresponds to the specified driver name.

Parameters

driverName	Name of driver
pluginMgr	Plug in manager, use default if NULL

§ CreateDeviceByName()

static PVideoInputDevice* PVideoInputDevice::CreateDeviceByName	(	const PString &	deviceName,
		const PString &	driverName = `PString::Empty()`,
		PPluginManager *	pluginMgr = `NULL`
	)

static

Parameters

deviceName	Name of device
driverName	Name of driver (if any)
pluginMgr	Plug in manager, use default if NULL

§ CreateOpenedDevice() [1/2]

static PVideoInputDevice* PVideoInputDevice::CreateOpenedDevice	(	const PString &	driverName,
		const PString &	deviceName,
		PBoolean	startImmediate = `true`,
		PPluginManager *	pluginMgr = `NULL`
	)

static

Create an opened video input device that corresponds to the specified names.

If the driverName parameter is an empty string or "*" then CreateDeviceByName is used with the deviceName parameter which is assumed to be a value returned from GetDriversDeviceNames().

Parameters

driverName	Name of driver
deviceName	Name of device
startImmediate	Immediately start grabbing
pluginMgr	Plug in manager, use default if NULL

§ CreateOpenedDevice() [2/2]

static PVideoInputDevice* PVideoInputDevice::CreateOpenedDevice	(	const OpenArgs &	args,
		PBoolean	startImmediate = `true`
	)

static

Create an opened video output device that corresponds to the specified arguments.

Parameters

args	Parameters to set on opened device
startImmediate	Immediately start display

§ FlowControl()

virtual bool PVideoInputDevice::FlowControl ( const void * flowData )

virtual

Pass data to the inputdevice for flowControl determination.

§ GetCaptureMode()

virtual int PVideoInputDevice::GetCaptureMode ( ) const

virtual

Returns the current capture mode.

See SetCaptureMode() for more details. A return value of -1 indicates an error or the mode is not supported.

§ GetDeviceCapabilities() [1/3]

virtual bool PVideoInputDevice::GetDeviceCapabilities ( Capabilities * capabilities ) const

inlinevirtual

Retrieve a list of Device Capabilities.

Parameters

capabilities List of supported capabilities

§ GetDeviceCapabilities() [2/3]

static PBoolean PVideoInputDevice::GetDeviceCapabilities	(	const PString &	deviceName,
		Capabilities *	capabilities,
		PPluginManager *	pluginMgr = `NULL`
	)

static

Retrieve a list of Device Capabilities for particular device.

Parameters

deviceName	Name of device
capabilities	List of supported capabilities
pluginMgr	Plug in manager, use default if NULL

§ GetDeviceCapabilities() [3/3]

static PBoolean PVideoInputDevice::GetDeviceCapabilities	(	const PString &	deviceName,
		const PString &	driverName,
		Capabilities *	caps,
		PPluginManager *	pluginMgr = `NULL`
	)

static

Retrieve a list of Device Capabilities for a particular driver.

Parameters

deviceName	Name of device
driverName	Device Driver
caps	List of supported capabilities
pluginMgr	Plug in manager, use default if NULL

§ GetDriverNames()

static PStringArray PVideoInputDevice::GetDriverNames ( PPluginManager * pluginMgr = NULL )

static

Get the list of available video input drivers (plug-ins)

Parameters

pluginMgr Plug in manager, use default if NULL

§ GetDriversDeviceNames()

static PStringArray PVideoInputDevice::GetDriversDeviceNames	(	const PString &	driverName,
		PPluginManager *	pluginMgr = `NULL`
	)

static

Get video input devices that correspond to the specified driver name.

If driverName is an empty string or the value "*" then this will return a list of unique device names across all of the available drivers. If two drivers have identical names for devices, then the string returned will be of the form driver+'\t'+device.

Parameters

driverName	Name of driver
pluginMgr	Plug in manager, use default if NULL

§ GetFrame()

virtual PBoolean PVideoInputDevice::GetFrame ( PBYTEArray & frame )

virtual

Grab a frame.

§ GetFrameData() [1/2]

virtual PBoolean PVideoInputDevice::GetFrameData	(	BYTE *	buffer,
		PINDEX *	bytesReturned,
		unsigned int &	flags
	)

virtual

Grab a frame, after a delay as specified by the frame rate.

Parameters

buffer	Buffer to receive frame
bytesReturned	Optional bytes returned.
flags	optional flags returned

§ GetFrameData() [2/2]

virtual PBoolean PVideoInputDevice::GetFrameData	(	BYTE *	buffer,
		PINDEX *	bytesReturned = `NULL`
	)

pure virtual

Parameters

buffer	Buffer to receive frame
bytesReturned	Optional bytes returned.

Implemented in PVideoInput1394DcDevice.

§ GetFrameDataNoDelay() [1/2]

virtual PBoolean PVideoInputDevice::GetFrameDataNoDelay	(	BYTE *	buffer,
		PINDEX *	bytesReturned,
		unsigned int &	flags
	)

virtual

Grab a frame.

Do not delay according to the current frame rate parameter.

Parameters

buffer	Buffer to receive frame
bytesReturned	Optional bytes returned.
flags	optional flags returned

§ GetFrameDataNoDelay() [2/2]

virtual PBoolean PVideoInputDevice::GetFrameDataNoDelay	(	BYTE *	buffer,
		PINDEX *	bytesReturned = `NULL`
	)

pure virtual

Parameters

buffer	Buffer to receive frame
bytesReturned	Optional bytes returned.

Implemented in PVideoInput1394DcDevice.

§ GetVideoInputControls()

virtual PVideoInputControl* PVideoInputDevice::GetVideoInputControls ( )

virtual

Get the devices video Input controls By Default return NULL;.

§ IsCapturing()

virtual PBoolean PVideoInputDevice::IsCapturing ( )

pure virtual

Determine if the video device I/O capture is in progress.

Implemented in PVideoInput1394DcDevice.

§ Open()

virtual PBoolean PVideoInputDevice::Open	(	const PString &	deviceName,
		PBoolean	startImmediate = `true`
	)

pure virtual

Open the device given the device name.

Parameters

deviceName	Device name to open
startImmediate	Immediately start device

Implements PVideoDevice.

Implemented in PVideoInput1394DcDevice.

§ SetCaptureMode()

virtual bool PVideoInputDevice::SetCaptureMode ( unsigned mode )

virtual

Set the capture modes for implementations that support them.

For example with Video For Windows, this is used to select picture (0) or video (1) modes.

In picture-mode the implementation requests a single frame from the connected camera device. The camera device then does nothing until the frame has been processed and the next is requested.

In video-mode the camera continuously sends new frames.

The default implementation does nothing but returns PFalse.

§ SetNearestFrameSize()

virtual PBoolean PVideoInputDevice::SetNearestFrameSize	(	unsigned	width,
		unsigned	height
	)

virtual

Set the nearest available frame size to be used.

Note that devices may not be able to produce the requested size, so this function picks the nearest available size.

Default behaviour simply calls SetFrameSize().

Parameters

width	New width of frame
height	New height of frame

Reimplemented from PVideoDevice.

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

videoio.h

Classes

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

§ ~PVideoInputDevice()

Member Function Documentation

§ CanCaptureVideo()

§ Close()

§ CreateDevice()

§ CreateDeviceByName()

§ CreateOpenedDevice() [1/2]

§ CreateOpenedDevice() [2/2]

§ FlowControl()

§ GetCaptureMode()

§ GetDeviceCapabilities() [1/3]

§ GetDeviceCapabilities() [2/3]

§ GetDeviceCapabilities() [3/3]

§ GetDriverNames()

§ GetDriversDeviceNames()

§ GetFrame()

§ GetFrameData() [1/2]

§ GetFrameData() [2/2]

§ GetFrameDataNoDelay() [1/2]

§ GetFrameDataNoDelay() [2/2]

§ GetVideoInputControls()

§ IsCapturing()

§ Open()

§ SetCaptureMode()

§ SetNearestFrameSize()