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PVideoInputDevice Class Referenceabstract

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

#include <videoio.h>

Inheritance diagram for PVideoInputDevice:
PVideoDevice PVideoFrameInfo PObject PVideoInput1394DcDevice

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 PVideoInputControlGetVideoInputControls ()
 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 PStringGetDeviceName () 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 PStringGetPreferredColourFormat ()
 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 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 PStringGetColourFormat () 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 PObjectClone () 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 Compare (const PObject &obj) const
 Compare the two objects and return their relative rank. 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 PVideoInputDeviceCreateDevice (const PString &driverName, PPluginManager *pluginMgr=NULL)
 Create the video input device that corresponds to the specified driver name. More...
 
static PVideoInputDeviceCreateDeviceByName (const PString &deviceName, const PString &driverName=PString::Empty(), PPluginManager *pluginMgr=NULL)
 
static PVideoInputDeviceCreateOpenedDevice (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 PVideoInputDeviceCreateOpenedDevice (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
 
PColourConverterconverter
 
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 ( )
inline

Create a new video input device.

Close the video input device on destruction.

References Close().

Member Function Documentation

virtual PBoolean PVideoInputDevice::CanCaptureVideo ( ) const
virtual

Is the device a camera, and obtain video.

Implements PVideoDevice.

virtual PBoolean PVideoInputDevice::Close ( )
inlinevirtual

Close the device.

Implements PVideoDevice.

Reimplemented in PVideoInput1394DcDevice.

Referenced by ~PVideoInputDevice().

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

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

Parameters
driverNameName of driver
pluginMgrPlug in manager, use default if NULL
static PVideoInputDevice* PVideoInputDevice::CreateDeviceByName ( const PString deviceName,
const PString driverName = PString::Empty(),
PPluginManager pluginMgr = NULL 
)
static
Parameters
deviceNameName of device
driverNameName of driver (if any)
pluginMgrPlug in manager, use default if NULL
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
driverNameName of driver
deviceNameName of device
startImmediateImmediately start grabbing
pluginMgrPlug in manager, use default if NULL
static PVideoInputDevice* PVideoInputDevice::CreateOpenedDevice ( const OpenArgs args,
PBoolean  startImmediate = true 
)
static

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

Parameters
argsParameters to set on opened device
startImmediateImmediately start display
virtual bool PVideoInputDevice::FlowControl ( const void *  flowData)
virtual

Pass data to the inputdevice for flowControl determination.

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.

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

Retrieve a list of Device Capabilities.

Parameters
capabilitiesList of supported capabilities

References PVideoDevice::GetDeviceName().

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

Retrieve a list of Device Capabilities for particular device.

Parameters
deviceNameName of device
capabilitiesList of supported capabilities
pluginMgrPlug in manager, use default if NULL
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
deviceNameName of device
driverNameDevice Driver
capsList of supported capabilities
pluginMgrPlug in manager, use default if NULL
static PStringArray PVideoInputDevice::GetDriverNames ( PPluginManager pluginMgr = NULL)
static

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

Parameters
pluginMgrPlug in manager, use default if NULL
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
driverNameName of driver
pluginMgrPlug in manager, use default if NULL
virtual PBoolean PVideoInputDevice::GetFrame ( PBYTEArray frame)
virtual

Grab a frame.

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
bufferBuffer to receive frame
bytesReturnedOptional bytes returned.
flagsoptional flags returned
virtual PBoolean PVideoInputDevice::GetFrameData ( BYTE *  buffer,
PINDEX *  bytesReturned = NULL 
)
pure virtual
Parameters
bufferBuffer to receive frame
bytesReturnedOptional bytes returned.

Implemented in PVideoInput1394DcDevice.

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
bufferBuffer to receive frame
bytesReturnedOptional bytes returned.
flagsoptional flags returned
virtual PBoolean PVideoInputDevice::GetFrameDataNoDelay ( BYTE *  buffer,
PINDEX *  bytesReturned = NULL 
)
pure virtual
Parameters
bufferBuffer to receive frame
bytesReturnedOptional bytes returned.

Implemented in PVideoInput1394DcDevice.

virtual PVideoInputControl* PVideoInputDevice::GetVideoInputControls ( )
virtual

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

virtual PBoolean PVideoInputDevice::IsCapturing ( )
pure virtual

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

Implemented in PVideoInput1394DcDevice.

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

Open the device given the device name.

Parameters
deviceNameDevice name to open
startImmediateImmediately start device

Implements PVideoDevice.

Implemented in PVideoInput1394DcDevice.

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.

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
widthNew width of frame
heightNew height of frame

Reimplemented from PVideoDevice.


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