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VideoWrapper.h File Reference

Declares VideoWrapper, an interface adapter for multiple video capture APIs. More...

#include "VideoWrapperTypes.h"
#include <time.h>

Go to the source code of this file.

Camera Library Management Functions

VW_API VWResult VW_API_ENTRY VIDEO_loadLibrary (char *szLibIdentifier, char *szLibImplementation)

Dynamically loads support for a camera library.

typedef void (VW_API_ENTRY VWPrintFcn)(char *)

Type definition for print callback functions.

VW_API VWResult VW_API_ENTRY VIDEO_setPrintFunction (VWPrintFcn *fp)

Sets a callback function that may be used for printing messages from the video libraries.

Camera Management Functions

VW_API VWResult VW_API_ENTRY VIDEO_openVideo (char *szInit, VWHVideo *phVideo)

Intializes a video camera.

VW_API VWResult VW_API_ENTRY VIDEO_close (VWHVideo hVideo)

Close the video camera.

VW_API VWResult VW_API_ENTRY VIDEO_startVideo (VWHVideo hVideo)

Starts aquiring frames from the camera.

VW_API VWResult VW_API_ENTRY VIDEO_stopVideo (VWHVideo hVideo)

Stops aquiring frames from the camera.

VW_API VWResult VW_API_ENTRY VIDEO_resetVideo (VWHVideo hVideo, VWBool bAutomatic)

Resets all the camera parameters to defaults.

Frame Capture Functions

VW_API VWResult VW_API_ENTRY VIDEO_getFrame (VWHVideo hVideo, unsigned char **ppbFrame, timeval *pTimestamp)

Polls for new video frame.

VW_API VWResult VW_API_ENTRY VIDEO_releaseFrame (VWHVideo hVideo)

Releases the frame so that memory may be deallocated.

VW_API VWResult VW_API_ENTRY VIDEO_getFrameRate (VWHVideo hVideo, double *pdFrameRate)

Gets the frame rate of the camera as frames per second.

Image Format Accessor Functions

VW_API VWResult VW_API_ENTRY VIDEO_getWidth (VWHVideo hVideo, int *pnWidth)

Gets the video width.

VW_API VWResult VW_API_ENTRY VIDEO_getHeight (VWHVideo hVideo, int *pnHeight)

Gets the video height.

VW_API VWResult VW_API_ENTRY VIDEO_getPixelFormat (VWHVideo hVideo, int *pnFormat)

Gets the pixel format.

VW_API VWResult VW_API_ENTRY VIDEO_getDepth (VWHVideo hVideo, int *pnDepth)

Gets color depth as bits per pixel.

Error Reporting Functions

VW_API char *VW_API_ENTRY VIDEO_getErrDescription (VWResult resultCode)

Gets a string describing the given VWResult code.

Camera Property Functions

VW_API VWResult VW_API_ENTRY VIDEO_showPropertiesDialog (VWHVideo hVideo)

Displays the a pop-up property window associated with this device.

VW_API VWResult VW_API_ENTRY VIDEO_setPropertyLong (VWHVideo hVideo, VWCamProp propId, long lValue1, long lValue2=0L, VWBool bAuto=FALSE)

Sets a long-typed camera property such as white balance, gain, etc.

VW_API VWResult VW_API_ENTRY VIDEO_getPropertyLong (VWHVideo hVideo, VWCamProp propId, long *plValue1=NULL, long *plValue2=NULL, VWBool *pbAuto=NULL)

Gets a long-typed camera property such as white balance, gain, etc.

VW_API VWResult VW_API_ENTRY VIDEO_getPropertyRangeLong (VWHVideo hVideo, VWCamProp propId, long *plMinValue=NULL, long *plMaxValue=NULL, VWBool *pbAuto=NULL)

Gets the valid range for a long-typed camera property such as white balance, gain, etc.

VW_API VWResult VW_API_ENTRY VIDEO_setPropertyString (VWHVideo hVideo, VWCamProp propId, char *szValue)

Sets a string-typed camera property.

VW_API VWResult VW_API_ENTRY VIDEO_getPropertyString (VWHVideo hVideo, VWCamProp propId, char *szValue, int nSize)

Gets a string-typed camera property.

Disk Capture Functions

VW_API VWResult VW_API_ENTRY VIDEO_startFramesToDisk (VWHVideo hVideo, char *szOutputDirectory, long lBufferSizeLimit=VW_UNLIMITED_BUFFER)

Starts the capture of video frames to disk.

VW_API VWResult VW_API_ENTRY VIDEO_stopFramesToDisk (VWHVideo hVideo, int *pnFrames=NULL)

Stops the capture of frames to disk.

Replay Camera Functions

These functions operate only on the "replay" camera.

VW_API VWResult VW_API_ENTRY VIDEO_replaySetPlaybackPosition (VWHVideo hVideo, timeval tvNewPosition)

Sets the current position for video playback to permit random access.

VW_API VWResult VW_API_ENTRY VIDEO_replaySetPlaybackLoop (VWHVideo hVideo, VWBool bLoop)

Sets the loop state of the replay camera.

VW_API VWBool VW_API_ENTRY VIDEO_replayIsPlaybackFinished (VWHVideo hVideo, VWBool *pbFinished)

Checks to see if playback is finished.

Detailed Description

Declares VideoWrapper, an interface adapter for multiple video capture APIs.

Function Documentation

VW_API VWResult VW_API_ENTRY VIDEO_close ( VWHVideo hVideo )

Close the video camera.

Parameters:

hVideo Handle to video camera.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_getDepth ( VWHVideo hVideo,

int * pnDepth

)

Gets color depth as bits per pixel.

Parameters:

hVideo Handle to video camera.

[out] pnDepth Pointer returning the bits per pixel.

Returns:
VWResult indicating success or failure.

VW_API char* VW_API_ENTRY VIDEO_getErrDescription ( VWResult resultCode )

Gets a string describing the given VWResult code.

Parameters:

resultCode VWResult code to describe.

Returns:
A string describing the VWResult code

VW_API VWResult VW_API_ENTRY VIDEO_getFrame ( VWHVideo hVideo,

unsigned char ** ppbFrame,

timeval * pTimestamp

)

Polls for new video frame.

Parameters:

hVideo Handle to video camera.

[out] ppbFrame Pointer returning the captured video frame. Memory is alocated by the camera library. If no frame is availible, ppbFrame returns NULL.

[out] pTimestamp Pointer returning the timestamp of the captured video frame.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_getFrameRate ( VWHVideo hVideo,

double * pdFrameRate

)

Gets the frame rate of the camera as frames per second.

Parameters:

hVideo Handle to video camera.

[out] pdFrameRate Pointer returning the frame rate of the camera.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_getHeight ( VWHVideo hVideo,

int * pnHeight

)

Gets the video height.

Parameters:

hVideo Handle to video camera.

[out] pnHeight Pointer returning the height of the video.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_getPixelFormat ( VWHVideo hVideo,

int * pnFormat

)

Gets the pixel format.

Parameters:

hVideo Handle to video camera.

[out] pnFormat Pointer returning an integer expressing the pixel format.

Returns:
VWResult indicating success or failure.

See also:
VWPixelFormat

VW_API VWResult VW_API_ENTRY VIDEO_getPropertyLong ( VWHVideo hVideo,

VWCamProp propId,

long * plValue1 = NULL,

long * plValue2 = NULL,

VWBool * pbAuto = NULL

)

Gets a long-typed camera property such as white balance, gain, etc.
Some properties are composed of two values. Symbols for camera properties are defined in VideoWrapperTypes.h.

Parameters:

propId Identifier of the property.

[out] plValue1 Pointer returning first property value.

[out] plValue2 Pointer returning second property value. Not used with most properties.

Returns:
VWResult indicating success or failure.

See also:
VWCamProp

VW_API VWResult VW_API_ENTRY VIDEO_getPropertyRangeLong ( VWHVideo hVideo,

VWCamProp propId,

long * plMinValue = NULL,

long * plMaxValue = NULL,

VWBool * pbAuto = NULL

)

Gets the valid range for a long-typed camera property such as white balance, gain, etc.
Symbols for camera properties are defined in VideoWrapperTypes.h.

Parameters:

propId Identifier of the property.

lValue1 First property value.

lValue2 Second property value. Not used with most properties.

Returns:
VWResult indicating success or failure.

See also:
VWCamProp

VW_API VWResult VW_API_ENTRY VIDEO_getPropertyString ( VWHVideo hVideo,

VWCamProp propId,

char * szValue,

int nSize

)

Gets a string-typed camera property.

Parameters:

propId Identifier of the property.

[in] szValue Property value.

Returns:
VWResult indicating success or failure.

See also:
VWCamProp

VW_API VWResult VW_API_ENTRY VIDEO_getWidth ( VWHVideo hVideo,

int * pnWidth

)

Gets the video width.

Parameters:

hVideo Handle to video camera.

[out] pnWidth Pointer returning the width of the video.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_loadLibrary ( char * szLibIdentifier,

char * szLibImplementation

)

Dynamically loads support for a camera library.
Some camera libraries are 'preset' and VideoWrapper can load them automatically, however this function allows VideoWrapper to be extended at runtime to support additional camera libraries.

Parameters:

[in] szLibIdentifier Identifier to represent library in calls to VIDEO_openVideo.

[in] szLibImplementation Platform-specific implementation string.

Windows: File name of DLL implementing support.
Apple: Unsupported.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_openVideo ( char * szInit,

VWHVideo * phVideo

)

Intializes a video camera.

Parameters:

[in] szInit An implementation-dependent string used to configure the camera. Consult the 'VideoWrapper_xxx Details' page for the API adapter you are instantiating for the string format. Generally, however, the string is formatted as follows: "libId: camNum width frameRate colorMode scale outputMode" where

libId is the identifier for the API adapter library.
camNum is a number (starting at 0) representing the camera to open.
width is the desired frame width.
frameRate is the desired frame rate
colorMode is a string specifying the format of the desired color mode (e.g. rgb, yuv).
scale is 0 or 1. 1 means a mode of 2x or 4x the size can be used, and scaled to the correct size.
A noteable exception is the "replay" camera library, which will replay video frames that have been previously saved. In this case szInit takes the form: "replay: directory" where

replay is the identifier of the replay camera library.
directory is the path to the directory containing the saved video frames.

[out] phVideo Pointer to the handle for opened camera.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_releaseFrame ( VWHVideo hVideo )

Releases the frame so that memory may be deallocated.

Parameters:

hVideo Handle to video camera.

Returns:
VWResult indicating success or failure.

VW_API VWBool VW_API_ENTRY VIDEO_replayIsPlaybackFinished ( VWHVideo hVideo,

VWBool * pbFinished

)

Checks to see if playback is finished.
Will return true after a call to getNextFrame goes past the last saved frame.

Parameters:

hVideo Handle to video camera.

[out] pbFinished Pointer returning TRUE if playback is finished, otherwise FALSE.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_replaySetPlaybackLoop ( VWHVideo hVideo,

VWBool bLoop

)

Sets the loop state of the replay camera.
Has no effect with other camera libraries. If the loop state is true, video playback will loop when the end is reached.

Parameters:

hVideo Handle to video camera.

bLoop The new loop state.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_replaySetPlaybackPosition ( VWHVideo hVideo,

timeval tvNewPosition

)

Sets the current position for video playback to permit random access.

Parameters:

hVideo Handle to video camera.

tvNewPosition Time offset from the beginning of the captured video.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_resetVideo ( VWHVideo hVideo,

VWBool bAutomatic

)

Resets all the camera parameters to defaults.

Parameters:

hVideo Handle to video camera.

bAutomatic If true, allow the camera to auto-adust.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_setPrintFunction ( VWPrintFcn * fp )

Sets a callback function that may be used for printing messages from the video libraries.

Parameters:

function: ptr to print function

VW_API VWResult VW_API_ENTRY VIDEO_setPropertyLong ( VWHVideo hVideo,

VWCamProp propId,

long lValue1,

long lValue2 = 0L,

VWBool bAuto = FALSE

)

Sets a long-typed camera property such as white balance, gain, etc.
Some properties are composed of two values. Symbols for camera properties are defined in VideoWrapperTypes.h.

Parameters:

propId Identifier of the property.

lValue1 First property value.

lValue2 Second property value. Not used with most properties.

Returns:
VWResult indicating success or failure.

See also:
VWCamProp

VW_API VWResult VW_API_ENTRY VIDEO_setPropertyString ( VWHVideo hVideo,

VWCamProp propId,

char * szValue

)

Sets a string-typed camera property.

Parameters:

propId Identifier of the property.

[in] szValue Property value.

Returns:
VWResult indicating success or failure.

See also:
VWCamProp

VW_API VWResult VW_API_ENTRY VIDEO_showPropertiesDialog ( VWHVideo hVideo )

Displays the a pop-up property window associated with this device.
Not supported by all camera libraries.

Parameters:

hVideo Handle to video camera.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_startFramesToDisk ( VWHVideo hVideo,

char * szOutputDirectory,

long lBufferSizeLimit = VW_UNLIMITED_BUFFER

)

Starts the capture of video frames to disk.
Frames are written as TIFFs. This version does not write frames to disk until VIDEO_stopFramesToDisk is executed. Unless lBufferSizeLimit is set to VW_UNLIMITED_BUFFER, frames will be discarded when the buffer limit is reached.

Parameters:

hVideo Handle to video camera.

szOutputDirectory Directory to write frames. start-time for video capture.

lBufferSizeLimit Limit for capture buffer in bytes. Set to VW_UNLIMITED_BUFFER for unlimited buffer size.

Returns:
VWResult indicating success or failure.

Note:
The current implementation is not very efficient and recommended only for small captures.

VW_API VWResult VW_API_ENTRY VIDEO_startVideo ( VWHVideo hVideo )

Starts aquiring frames from the camera.

Parameters:

hCam Handle to video camera.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_stopFramesToDisk ( VWHVideo hVideo,

int * pnFrames = NULL

)

Stops the capture of frames to disk.

Parameters:

hVideo Handle to video camera.

[out] pnFrames Pointer returning the number of frames captured.

Returns:
VWResult indicating success or failure.

VW_API VWResult VW_API_ENTRY VIDEO_stopVideo ( VWHVideo hVideo )

Stops aquiring frames from the camera.

Parameters:

hCam Handle to video camera.

Returns:
VWResult indicating success or failure.

Generated on Tue Oct 18 12:18:51 2005 for VideoWrapper API by

1.4.1


Camera Library Management Functions
VW_API VWResult VW_API_ENTRY	VIDEO_loadLibrary (char szLibIdentifier, char szLibImplementation)
	Dynamically loads support for a camera library.
typedef	void (VW_API_ENTRY VWPrintFcn)(char *)
	Type definition for print callback functions.
VW_API VWResult VW_API_ENTRY	VIDEO_setPrintFunction (VWPrintFcn *fp)
	Sets a callback function that may be used for printing messages from the video libraries.
Camera Management Functions
VW_API VWResult VW_API_ENTRY	VIDEO_openVideo (char szInit, VWHVideo phVideo)
	Intializes a video camera.
VW_API VWResult VW_API_ENTRY	VIDEO_close (VWHVideo hVideo)
	Close the video camera.
VW_API VWResult VW_API_ENTRY	VIDEO_startVideo (VWHVideo hVideo)
	Starts aquiring frames from the camera.
VW_API VWResult VW_API_ENTRY	VIDEO_stopVideo (VWHVideo hVideo)
	Stops aquiring frames from the camera.
VW_API VWResult VW_API_ENTRY	VIDEO_resetVideo (VWHVideo hVideo, VWBool bAutomatic)
	Resets all the camera parameters to defaults.
Frame Capture Functions
VW_API VWResult VW_API_ENTRY	VIDEO_getFrame (VWHVideo hVideo, unsigned char *ppbFrame, timeval pTimestamp)
	Polls for new video frame.
VW_API VWResult VW_API_ENTRY	VIDEO_releaseFrame (VWHVideo hVideo)
	Releases the frame so that memory may be deallocated.
VW_API VWResult VW_API_ENTRY	VIDEO_getFrameRate (VWHVideo hVideo, double *pdFrameRate)
	Gets the frame rate of the camera as frames per second.
Image Format Accessor Functions
VW_API VWResult VW_API_ENTRY	VIDEO_getWidth (VWHVideo hVideo, int *pnWidth)
	Gets the video width.
VW_API VWResult VW_API_ENTRY	VIDEO_getHeight (VWHVideo hVideo, int *pnHeight)
	Gets the video height.
VW_API VWResult VW_API_ENTRY	VIDEO_getPixelFormat (VWHVideo hVideo, int *pnFormat)
	Gets the pixel format.
VW_API VWResult VW_API_ENTRY	VIDEO_getDepth (VWHVideo hVideo, int *pnDepth)
	Gets color depth as bits per pixel.
Error Reporting Functions
VW_API char *VW_API_ENTRY	VIDEO_getErrDescription (VWResult resultCode)
	Gets a string describing the given VWResult code.
Camera Property Functions
VW_API VWResult VW_API_ENTRY	VIDEO_showPropertiesDialog (VWHVideo hVideo)
	Displays the a pop-up property window associated with this device.
VW_API VWResult VW_API_ENTRY	VIDEO_setPropertyLong (VWHVideo hVideo, VWCamProp propId, long lValue1, long lValue2=0L, VWBool bAuto=FALSE)
	Sets a long-typed camera property such as white balance, gain, etc.
VW_API VWResult VW_API_ENTRY	VIDEO_getPropertyLong (VWHVideo hVideo, VWCamProp propId, long plValue1=NULL, long plValue2=NULL, VWBool *pbAuto=NULL)
	Gets a long-typed camera property such as white balance, gain, etc.
VW_API VWResult VW_API_ENTRY	VIDEO_getPropertyRangeLong (VWHVideo hVideo, VWCamProp propId, long plMinValue=NULL, long plMaxValue=NULL, VWBool *pbAuto=NULL)
	Gets the valid range for a long-typed camera property such as white balance, gain, etc.
VW_API VWResult VW_API_ENTRY	VIDEO_setPropertyString (VWHVideo hVideo, VWCamProp propId, char *szValue)
	Sets a string-typed camera property.
VW_API VWResult VW_API_ENTRY	VIDEO_getPropertyString (VWHVideo hVideo, VWCamProp propId, char *szValue, int nSize)
	Gets a string-typed camera property.
Disk Capture Functions
VW_API VWResult VW_API_ENTRY	VIDEO_startFramesToDisk (VWHVideo hVideo, char *szOutputDirectory, long lBufferSizeLimit=VW_UNLIMITED_BUFFER)
	Starts the capture of video frames to disk.
VW_API VWResult VW_API_ENTRY	VIDEO_stopFramesToDisk (VWHVideo hVideo, int *pnFrames=NULL)
	Stops the capture of frames to disk.
Replay Camera Functions
These functions operate only on the "replay" camera.
VW_API VWResult VW_API_ENTRY	VIDEO_replaySetPlaybackPosition (VWHVideo hVideo, timeval tvNewPosition)
	Sets the current position for video playback to permit random access.
VW_API VWResult VW_API_ENTRY	VIDEO_replaySetPlaybackLoop (VWHVideo hVideo, VWBool bLoop)
	Sets the loop state of the replay camera.
VW_API VWBool VW_API_ENTRY	VIDEO_replayIsPlaybackFinished (VWHVideo hVideo, VWBool *pbFinished)
	Checks to see if playback is finished.