PVideoDevice Class Reference

This class defines a video device. More...

#include <videoio.h>

Inheritance diagram for PVideoDevice:


Public Types
	PAL
	NTSC
	SECAM
	Auto
	NumVideoFormats
enum	VideoFormat { PAL, NTSC, SECAM, Auto, NumVideoFormats }
Public Member Functions
virtual	~PVideoDevice ()
	Delete structures created by PVideoDevice();.
const PString &	GetDeviceName () const
	Get the device name of the open device.
virtual PStringArray	GetDeviceNames () const =0
	Get a list of all of the drivers available.
virtual PBoolean	OpenFull (const OpenArgs &args, PBoolean startImmediate=true)
	Open the device given the device name.
virtual PBoolean	Open (const PString &deviceName, PBoolean startImmediate=true)=0
	Open the device given the device name.
virtual PBoolean	IsOpen ()=0
	Determine if the device is currently open.
virtual PBoolean	Close ()=0
	Close the device.
virtual PBoolean	Start ()=0
	Start the video device I/O capture.
virtual PBoolean	Stop ()=0
	Stop the video device I/O capture.
virtual PBoolean	SetVideoFormat (VideoFormat videoFormat)
	Set the video format to be used.
virtual VideoFormat	GetVideoFormat () const
	Get the video format being used.
virtual int	GetNumChannels ()
	Get the number of video channels available on the device.
virtual PBoolean	SetChannel (int channelNumber)
	Set the video channel to be used on the device.
virtual int	GetChannel () const
	Get the video channel to be used on the device.
virtual PBoolean	SetColourFormatConverter (const PString &colourFormat)
	Set the colour format to be used, trying converters if available.
virtual PBoolean	GetVFlipState ()
	Get the video conversion vertical flip state.
virtual PBoolean	SetVFlipState (PBoolean newVFlipState)
	Set the video conversion vertical flip state.
virtual PBoolean	GetFrameSizeLimits (unsigned &minWidth, unsigned &minHeight, unsigned &maxWidth, unsigned &maxHeight)
	Get the minimum & maximum size of a frame on the device.
virtual PBoolean	SetFrameSizeConverter (unsigned width, unsigned height, ResizeMode resizeMode=eMaxResizeMode)
	Set the frame size to be used, trying converters if available.
virtual PBoolean	SetFrameSizeConverter (unsigned width, unsigned height, PBoolean)
	Set the frame size to be used, trying converters if available.
virtual PBoolean	SetFrameSize (unsigned width, unsigned height)
	Set the frame size to be used.
virtual PBoolean	GetFrameSize (unsigned &width, unsigned &height) const
	Get the frame size being used.
virtual PINDEX	GetMaxFrameBytes ()=0
	Get the maximum frame size in bytes.
int	GetLastError () const
	Get the last error code.
virtual PBoolean	CanCaptureVideo () const =0
	Is the device a camera, and obtain video.
virtual int	GetBrightness ()
	Get the brightness of the image.
virtual PBoolean	SetBrightness (unsigned newBrightness)
	Set brightness of the image.
virtual int	GetWhiteness ()
	Get the whiteness of the image.
virtual PBoolean	SetWhiteness (unsigned newWhiteness)
	Set whiteness of the image.
virtual int	GetColour ()
	Get the colour of the image.
virtual PBoolean	SetColour (unsigned newColour)
	Set colour of the image.
virtual int	GetContrast ()
	Get the contrast of the image.
virtual PBoolean	SetContrast (unsigned newContrast)
	Set contrast of the image.
virtual int	GetHue ()
	Get the hue of the image.
virtual PBoolean	SetHue (unsigned newHue)
	Set hue of the image.
virtual PBoolean	GetParameters (int whiteness, int brightness, int colour, int contrast, int *hue)
	Return whiteness, brightness, colour, contrast and hue in one call.
virtual PBoolean	SetVideoChannelFormat (int channelNumber, VideoFormat videoFormat)
	Set VideoFormat and VideoChannel in one ioctl.
void	SetPreferredColourFormat (const PString &colourFmt)
	Set preferred native colour format from video capture device.
const PString &	GetPreferredColourFormat ()
	Get preferred native colour format from video capture device.
Protected Member Functions
	PVideoDevice ()
	Create a new video device (input or output).
PINDEX	GetMaxFrameBytesConverted (PINDEX rawFrameBytes) const
Protected Attributes
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
Classes
struct	OpenArgs

Detailed Description

This class defines a video device.

This class is used to abstract the few parameters that are common to both\ input and output devices.

Example colour formats are:

"Grey" Simple 8 bit linear grey scale "Gray" Synonym for Grey "RGB32" 32 bit RGB "RGB24" 24 bit RGB "RGB565" 16 bit RGB (6 bit green) "RGB555" 15 bit RGB "YUV422" YUV 4:2:2 packed "YUV422P" YUV 4:2:2 planar "YUV411" YUV 4:1:1 packed "YUV411P" YUV 4:1:1 planar "YUV420" YUV 4:2:0 packed "YUV420P" YUV 4:2:0 planar "YUV410" YUV 4:1:0 packed "YUV410P" YUV 4:1:0 planar "MJPEG" Motion JPEG "UYVY422" YUV 4:2:2 packed as U Y V Y U Y V Y ... "UYV444" YUV 4:4:4 packed as U Y V U Y V ... They are used in IEEE 1394 digital cameras. The specification is found at http://www.1394ta.org/Download/Technology/Specifications/2000/IIDC_Spec_v1_30.pdf

Member Enumeration Documentation

enum PVideoDevice::VideoFormat

Enumerator:

PAL
NTSC
SECAM
Auto
NumVideoFormats

Constructor & Destructor Documentation

PVideoDevice::PVideoDevice ( ) [protected]

Create a new video device (input or output).

virtual PVideoDevice::~PVideoDevice ( ) [virtual]

Delete structures created by PVideoDevice();.

Member Function Documentation

virtual PBoolean PVideoDevice::CanCaptureVideo ( ) const [pure virtual]

Is the device a camera, and obtain video.

Implemented in PVideoOutputDevice, and PVideoInputDevice.

virtual PBoolean PVideoDevice::Close ( ) [pure virtual]

Close the device.

Implemented in PVideoOutputDevice, PVideoInputDevice, and PVideoInput1394DcDevice.

virtual int PVideoDevice::GetBrightness ( ) [virtual]

Get the brightness of the image.

0xffff-Very bright. -1 is unknown.

Reimplemented in PVideoInput1394DcDevice.

virtual int PVideoDevice::GetChannel ( ) const [virtual]

Get the video channel to be used on the device.

Default behaviour returns the value of the channelNumber variable.

virtual int PVideoDevice::GetColour ( ) [virtual]

Get the colour of the image.

0xffff-lots of colour. -1 is unknown.

Reimplemented in PVideoInput1394DcDevice.

virtual int PVideoDevice::GetContrast ( ) [virtual]

Get the contrast of the image.

0xffff-High contrast. -1 is unknown.

Reimplemented in PVideoInput1394DcDevice.

const PString& PVideoDevice::GetDeviceName ( ) const [inline]

Get the device name of the open device.

virtual PStringArray PVideoDevice::GetDeviceNames ( ) const [pure virtual]

Get a list of all of the drivers available.

virtual PBoolean PVideoDevice::GetFrameSize	(	unsigned &	width,
		unsigned &	height
	)			const `[virtual]`

Get the frame size being used.

Default behaviour returns the value of the frameWidth and frameHeight variable and returns true.

Reimplemented from PVideoFrameInfo.

virtual PBoolean PVideoDevice::GetFrameSizeLimits	(	unsigned &	minWidth,
		unsigned &	minHeight,
		unsigned &	maxWidth,
		unsigned &	maxHeight
	)			`[virtual]`

Get the minimum & maximum size of a frame on the device.

Default behaviour returns the value 1 to UINT_MAX for both and returns false.

Parameters:

minWidth	Variable to receive minimum width
minHeight	Variable to receive minimum height
maxWidth	Variable to receive maximum width
maxHeight	Variable to receive maximum height

Reimplemented in PVideoInput1394DcDevice.

virtual int PVideoDevice::GetHue ( ) [virtual]

Get the hue of the image.

0xffff-High hue. -1 is unknown.

Reimplemented in PVideoInput1394DcDevice.

int PVideoDevice::GetLastError ( ) const [inline]

Get the last error code.

This is a platform dependent number.

virtual PINDEX PVideoDevice::GetMaxFrameBytes ( ) [pure virtual]

Get the maximum frame size in bytes.

Note a particular device may be able to provide variable length frames (eg motion JPEG) so will be the maximum size of all frames.

Implemented in PVideoOutputDeviceRGB, and PVideoInput1394DcDevice.

PINDEX PVideoDevice::GetMaxFrameBytesConverted ( PINDEX rawFrameBytes ) const [protected]

virtual int PVideoDevice::GetNumChannels ( ) [virtual]

Get the number of video channels available on the device.

Default behaviour returns 1.

Reimplemented in PVideoInput1394DcDevice.

virtual PBoolean PVideoDevice::GetParameters	(	int *	whiteness,
		int *	brightness,
		int *	colour,
		int *	contrast,
		int *	hue
	)			`[virtual]`

Return whiteness, brightness, colour, contrast and hue in one call.

Reimplemented in PVideoInput1394DcDevice.

const PString& PVideoDevice::GetPreferredColourFormat ( ) [inline]

Get preferred native colour format from video capture device.

Returns empty == no preference

virtual PBoolean PVideoDevice::GetVFlipState ( ) [virtual]

Get the video conversion vertical flip state.

Default action is to return false.

virtual VideoFormat PVideoDevice::GetVideoFormat ( ) const [virtual]

Get the video format being used.

Default behaviour returns the value of the videoFormat variable.

virtual int PVideoDevice::GetWhiteness ( ) [virtual]

Get the whiteness of the image.

0xffff-Very white. -1 is unknown.

Reimplemented in PVideoInput1394DcDevice.

virtual PBoolean PVideoDevice::IsOpen ( ) [pure virtual]

Determine if the device is currently open.

Implemented in PVideoInput1394DcDevice.

virtual PBoolean PVideoDevice::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

Implemented in PVideoInputDevice, and PVideoInput1394DcDevice.

virtual PBoolean PVideoDevice::OpenFull	(	const OpenArgs &	args,
		PBoolean	startImmediate = `true`
	)			`[virtual]`

Open the device given the device name.

Parameters:

args	Parameters to set on opened device
startImmediate	Immediately start device

virtual PBoolean PVideoDevice::SetBrightness ( unsigned newBrightness ) [virtual]

Set brightness of the image.

0xffff-Very bright.

Reimplemented in PVideoInput1394DcDevice.

virtual PBoolean PVideoDevice::SetChannel ( int channelNumber ) [virtual]

Set the video channel to be used on the device.

The channel number is an integer from 0 to GetNumChannels()-1. The special value of -1 will find the first working channel number.

Default behaviour sets the value of the channelNumber variable and then returns true.

Parameters:

channelNumber

New channel number for device.

Reimplemented in PVideoInput1394DcDevice.

virtual PBoolean PVideoDevice::SetColour ( unsigned newColour ) [virtual]

Set colour of the image.

0xffff-lots of colour.

Reimplemented in PVideoInput1394DcDevice.

virtual PBoolean PVideoDevice::SetColourFormatConverter ( const PString & colourFormat ) [virtual]

Set the colour format to be used, trying converters if available.

This function will set the colour format on the device to one that is compatible with a registered converter, and install that converter so that the correct format is used.

Reimplemented in PVideoInput1394DcDevice.

virtual PBoolean PVideoDevice::SetContrast ( unsigned newContrast ) [virtual]

Set contrast of the image.

0xffff-High contrast.

Reimplemented in PVideoInput1394DcDevice.

virtual PBoolean PVideoDevice::SetFrameSize	(	unsigned	width,
		unsigned	height
	)			`[virtual]`

Set the frame size to be used.

Note that devices may not be able to produce the requested size, and this function will fail. See SetFrameSizeConverter().

Default behaviour sets the frameWidth and frameHeight variables and returns true.

Parameters:

width	New width of frame
height	New height of frame

Reimplemented from PVideoFrameInfo.

Reimplemented in PVideoOutputDeviceRGB, and PVideoInput1394DcDevice.

virtual PBoolean PVideoDevice::SetFrameSizeConverter	(	unsigned	width,
		unsigned	height,
		PBoolean
	)			`[inline, virtual]`

Set the frame size to be used, trying converters if available.

Function used for Backward compatibility only. If the device does not support the size, a set of alternate resolutions are attempted. A converter is setup if possible.

Parameters: