PTLib  Version 2.14.3
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Pages
PVideoOutputDevice Class Referenceabstract

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

#include <videoio.h>

Inheritance diagram for PVideoOutputDevice:
Collaboration diagram for PVideoOutputDevice:

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 (unsigned x, unsigned y, unsigned width, unsigned height, const BYTE *data, PBoolean endFrame=true)=0
 Set a section of the output frame buffer. More...
 
virtual PBoolean SetFrameData (unsigned x, unsigned y, unsigned width, unsigned height, const BYTE *data, PBoolean endFrame, bool &keyFrameNeeded)
 
virtual PBoolean SetFrameData (unsigned x, unsigned y, unsigned width, unsigned height, unsigned sarWidth, unsigned sarHeight, const BYTE *data, PBoolean endFrame, bool &keyFrameNeeded, const void *mark)
 
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...
 
 P_DECLARE_STREAMABLE_ENUM (VideoFormat, PAL, NTSC, SECAM, Auto)
 
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 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 SetFrameSizeConverter (unsigned width, unsigned height, PBoolean)
 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 const PStringGetColourFormat () const
 Get the colour format 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 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...
 
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
 P_DECLARE_ENUM_EX (ResizeMode, eMaxResizeMode, eScale, 0, eCropCentre, eCropTopLeft)
 
 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 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...
 
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
unsigned GetTraceContextIdentifier () const
 Get PTRACE context identifier. More...
 
void SetTraceContextIdentifier (unsigned id)
 
void GetTraceContextIdentifier (PObject &obj)
 
void GetTraceContextIdentifier (PObject *obj)
 
void SetTraceContextIdentifier (const PObject &obj)
 
void SetTraceContextIdentifier (const PObject *obj)
 
virtual ~PObject ()
 
virtual PObjectClone () 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 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...
 
__inline const PObjectPTraceObjectInstance () const
 
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 PrintOn (ostream &strm) const
 Output the contents of the object to the stream. 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 PVideoOutputDeviceCreateDevice (const PString &driverName, PPluginManager *pluginMgr=NULL)
 Create the video output device that corresponds to the specified driver name. More...
 
static PVideoOutputDeviceCreateDeviceByName (const PString &deviceName, const PString &driverName=PString::Empty(), PPluginManager *pluginMgr=NULL)
 
static PVideoOutputDeviceCreateOpenedDevice (const PString &driverName, const PString &deviceName, PBoolean startImmediate=true, PPluginManager *pluginMgr=NULL)
 Create an opened video output device that corresponds to the specified names. More...
 
static PVideoOutputDeviceCreateOpenedDevice (const OpenArgs &args, PBoolean startImmediate=true)
 Create an opened video output device that corresponds to the specified arguments. 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
}
 
- 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
 
- Protected Attributes inherited from PVideoDevice
PCaselessString deviceName
 
int lastError
 
VideoFormat videoFormat
 
int channelNumber
 
PString preferredColourFormat
 
PBoolean nativeVerticalFlip
 
PColourConverterconverter
 
PBYTEArray frameStore
 
- Friends inherited from PObject

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.

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
driverNameName of driver
pluginMgrPlug in manager, use default if NULL
static PVideoOutputDevice* PVideoOutputDevice::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 PVideoOutputDevice* PVideoOutputDevice::CreateOpenedDevice ( const PString driverName,
const PString deviceName,
PBoolean  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
driverNameName of driver
deviceNameName of device
startImmediateImmediately start display
pluginMgrPlug in manager, use default if NULL
static PVideoOutputDevice* PVideoOutputDevice::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 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
pluginMgrPlug 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
driverNameName of driver
pluginMgrPlug 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 ( unsigned  x,
unsigned  y,
unsigned  width,
unsigned  height,
const BYTE *  data,
PBoolean  endFrame = true 
)
pure virtual

Set a section of the output frame buffer.

Parameters
xHorizontal position in frame where data is put
yVertical position in frame where data is put
widthWidth of area in frame where data is put
heightHeight of area in frame where data is put
dataData to put into the video frame store
endFrameIndicate no more data for this video frame

Implemented in PVideoOutputDeviceRGB.

virtual PBoolean PVideoOutputDevice::SetFrameData ( unsigned  x,
unsigned  y,
unsigned  width,
unsigned  height,
const BYTE *  data,
PBoolean  endFrame,
bool &  keyFrameNeeded 
)
virtual
Parameters
xHorizontal position in frame where data is put
yVertical position in frame where data is put
widthWidth of area in frame where data is put
heightHeight of area in frame where data is put
dataData to put into the video frame store
endFrameIndicate no more data for this video frame
keyFrameNeededIndicates bad video and a new key frame is required
virtual PBoolean PVideoOutputDevice::SetFrameData ( unsigned  x,
unsigned  y,
unsigned  width,
unsigned  height,
unsigned  sarWidth,
unsigned  sarHeight,
const BYTE *  data,
PBoolean  endFrame,
bool &  keyFrameNeeded,
const void *  mark 
)
virtual
Parameters
xHorizontal position in frame where data is put
yVertical position in frame where data is put
widthWidth of area in frame where data is put
heightHeight of area in frame where data is put
sarWidthAspect ratio width of area in frame where data is put
sarHeightAspect ratio height of area in frame where data is put
dataData to put into the video frame store
endFrameIndicate no more data for this video frame
keyFrameNeededIndicates bad video and a new key frame is required
virtual bool PVideoOutputDevice::SetPosition ( int  x,
int  y 
)
virtual

Set the position of the output device, where relevant.

For devices such as files, this does nothing. For devices such as Windows, this sets the position of the window on the screen.

Returns: TRUE if the position can be set.

virtual PBoolean PVideoOutputDevice::Start ( )
inlinevirtual

Start the video device I/O display.

Implements PVideoDevice.

virtual PBoolean PVideoOutputDevice::Stop ( )
inlinevirtual

Stop the video device I/O display.

Implements PVideoDevice.


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