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

#include <videoio.h>

Inheritance diagram for PVideoOutputDevice:

Collaboration diagram for PVideoOutputDevice:

Classes
struct	FrameData

Public Member Functions
	PVideoOutputDevice ()
	Create a new video output device. More...

virtual	~PVideoOutputDevice ()
	Close the video output device on destruction. More...

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

virtual PBoolean	Start ()
	Start the video device I/O display. More...

virtual PBoolean	Stop ()
	Stop the video device I/O display. More...

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

virtual PBoolean	SetFrameData (const FrameData &frameData)=0
	Set a section of the output frame buffer. More...

bool	SetFrameData (unsigned x, unsigned y, unsigned width, unsigned height, const BYTE *data, bool endFrame=true)

bool	SetFrameData (unsigned x, unsigned y, unsigned width, unsigned height, const BYTE *data, bool endFrame, bool &keyFrameNeeded)

virtual PBoolean	DisableDecode ()
	Allow the outputdevice decide whether the decoder should ignore decode hence not render any output. More...

virtual PBoolean	GetPosition (int &x, int &y) const
	Get the position of the output device, where relevant. More...

virtual bool	SetPosition (int x, int y)
	Set the position of the output device, where relevant. More...

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

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

	P_DECLARE_STREAMABLE_ENUM (VideoFormat, PAL, NTSC, SECAM, Auto)

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

virtual PBoolean	IsOpen ()=0
	Determine if the device is currently open. 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 PStringArray	GetChannelNames ()
	Get the names 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 bool	SetFrameInfoConverter (const PVideoFrameInfo &info)
	Set the frame info to be used, trying converters if available. 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	SetNearestFrameSize (unsigned width, unsigned height)
	Set the nearest available frame size to be used. 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 PString	GetColourFormat () const
	Get the colour format being used. More...

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

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

virtual bool	GetAttributes (Attributes &attributes)
	Get video attributes. More...

virtual bool	SetAttributes (const Attributes &attributes)
	Set video attributes. More...

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

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

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

Public Member Functions inherited from PVideoFrameInfo
	P_DECLARE_ENUM_EX (ResizeMode, eMaxResizeMode, eScale, 0, eCropCentre, eCropTopLeft, eScaleKeepAspect)

	PVideoFrameInfo ()
	Construct video frame information. More...

	PVideoFrameInfo (unsigned frameWidth, unsigned frameHeight, const PString &colourFormat=PVideoFrameInfo::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 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 Storage Aspect Ratio size to be used. More...

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

virtual unsigned	GetSarWidth () const
	Get the width of the Storage Aspect Ratio being used. More...

virtual unsigned	GetSarHeight () const
	Get the height of the Storage Aspect Ratio 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 void	SetResizeMode (ResizeMode mode)
	Set the resize mode to be used. More...

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

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

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

Public Member Functions inherited from PObject
__inline unsigned	GetTraceContextIdentifier () const
	Get PTRACE context identifier. More...

__inline void	SetTraceContextIdentifier (unsigned id)

__inline void	SetTraceContextIdentifier (const PObject &obj)

__inline void	SetTraceContextIdentifier (const PObject *obj)

__inline void	CopyTraceContextIdentifier (PObject &obj) const

__inline void	CopyTraceContextIdentifier (PObject *obj) const

virtual	~PObject ()

__inline const char *	GetClass () const

__inline bool	IsClass (const char *name) const

__inline const PObject *	PTraceObjectInstance () const

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

template<class CLS >
CLS *	CloneAs () const
	As for Clone() but converts to specified type. More...

virtual PINDEX	HashFunction () const
	This function yields a hash value required by the `PDictionary` 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 output drivers (plug-ins) More...

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

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

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

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

static PVideoOutputDevice *	CreateOpenedDevice (const PString &deviceName, bool startImmediate=true, PPluginManager *pluginMgr=NULL)

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

Static Public Member Functions inherited from PVideoFrameInfo
static const PString &	YUV420P ()

static PINDEX	CalculateFrameBytes (unsigned width, unsigned height, const PString &colourFormat=PVideoFrameInfo::YUV420P())

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 __inline void	CopyTraceContextIdentifier (PObject &to, const PObject &from)

static __inline void	CopyTraceContextIdentifier (PObject &to, const PObject *from)

static __inline void	CopyTraceContextIdentifier (PObject *to, const PObject &from)

static __inline void	CopyTraceContextIdentifier (PObject to, const PObject from)

static __inline const char *	Class ()

static __inline const PObject *	PTraceObjectInstance (const char *)

static __inline const PObject *	PTraceObjectInstance (const PObject *obj)

template<typename T >
static Comparison	Compare2 (T v1, T v2)
	Compare two types, returning Comparison type. 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 PVideoFrameInfo
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

PString	GetDeviceNameFromOpenArgs (const OpenArgs &args) const

PString	ParseDeviceNameTokenString (const char token, const char defaultValue)

int	ParseDeviceNameTokenInt (const char *token, int defaultValue)

uint64_t	ParseDeviceNameTokenUnsigned (const char *token, uint64_t defaultValue)

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
PCaselessString	m_deviceName

int	m_lastError

VideoFormat	m_videoFormat

int	m_channelNumber

PString	m_preferredColourFormat

bool	m_nativeVerticalFlip

PColourConverter *	m_converter

PBYTEArray	m_frameStore

Protected Attributes inherited from PVideoFrameInfo
unsigned	m_frameWidth

unsigned	m_frameHeight

unsigned	m_sarWidth

unsigned	m_sarHeight

unsigned	m_frameRate

PString	m_colourFormat

ResizeMode	m_resizeMode

Protected Attributes inherited from PObject
unsigned	m_traceContextIdentifier

Detailed Description

This class defines a video output device.

typically, a window.

Constructor & Destructor Documentation

PVideoOutputDevice::PVideoOutputDevice ( )

Create a new video output device.

virtual PVideoOutputDevice::~PVideoOutputDevice ( )

inlinevirtual

Close the video output device on destruction.

References Close().

Member Function Documentation

virtual PBoolean PVideoOutputDevice::CanCaptureVideo ( ) const

virtual

Is the device a camera, and obtain video.

Implements PVideoDevice.

virtual PBoolean PVideoOutputDevice::Close ( )

inlinevirtual

Close the device.

Implements PVideoDevice.

Reimplemented in P_WXWINDOWS_DEVICE_CLASS.

Referenced by ~PVideoOutputDevice().

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

static

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

Parameters

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

static PVideoOutputDevice* PVideoOutputDevice::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

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

static

Create an opened video output 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 display
pluginMgr	Plug in manager, use default if NULL

Referenced by CreateOpenedDevice().

static PVideoOutputDevice* PVideoOutputDevice::CreateOpenedDevice	(	const PString &	deviceName,
		bool	startImmediate = `true`,
		PPluginManager *	pluginMgr = `NULL`
	)

inlinestatic

Parameters

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

References CreateOpenedDevice(), and PString::Empty().

static PVideoOutputDevice* PVideoOutputDevice::CreateOpenedDevice	(	const OpenArgs &	args,
		bool	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

virtual PBoolean PVideoOutputDevice::DisableDecode ( )

virtual

Allow the outputdevice decide whether the decoder should ignore decode hence not render any output.

Returns: false if to decode and render.

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

static

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

Parameters

pluginMgr Plug in manager, use default if NULL

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

static

Get video output 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

virtual PBoolean PVideoOutputDevice::GetPosition	(	int &	x,
		int &	y
	)		const

virtual

Get the position of the output device, where relevant.

For devices such as files, this always returns zeros. For devices such as Windows, this is the position of the window on the screen.

Returns: TRUE if the position is available.

virtual PBoolean PVideoOutputDevice::SetFrameData ( const FrameData & frameData )

pure virtual

Set a section of the output frame buffer.

Parameters

frameData Data for frame output

Implemented in PVideoOutputDeviceRGB.

bool PVideoOutputDevice::SetFrameData	(	unsigned	x,
		unsigned	y,
		unsigned	width,
		unsigned	height,
		const BYTE *	data,
		bool	endFrame = `true`
	)

Parameters

x	Horizontal position in frame where data is put
y	Vertical position in frame where data is put
width	Width of area in frame where data is put
height	Height of area in frame where data is put
data	Data to put into the video frame store
endFrame	Indicate no more data for this video frame

bool PVideoOutputDevice::SetFrameData	(	unsigned	x,
		unsigned	y,
		unsigned	width,
		unsigned	height,
		const BYTE *	data,
		bool	endFrame,
		bool &	keyFrameNeeded
	)

Parameters

x	Horizontal position in frame where data is put
y	Vertical position in frame where data is put
width	Width of area in frame where data is put
height	Height of area in frame where data is put
data	Data to put into the video frame store
endFrame	Indicate no more data for this video frame
keyFrameNeeded	Indicates bad video and a new key frame is required