TWebcam

Source: source/classes/twebcam.prg

Hierarchy: TWebcam → TControl

TWebcam provides live webcam preview and capture functionality using the Video for Windows (VFW) API. It is a visual control that displays the camera feed within a FiveWin window and supports snapshot capture, video format dialogs, and video source configuration.

WEBCAM Command

@ nRow, nCol WEBCAM oCam OF oWnd SIZE nW, nH INIT lInit

Key DATA Members

DATA	Type	Default	Description
`hWebcam`	Numeric		Handle to the VFW capture window
`cName`	Character		Webcam driver description
`cVersion`	Character		Webcam driver version string
`nRateRefresh`	Numeric	`66`	Preview refresh rate in milliseconds
`isScale`	Logical	`.T.`	Scale preview to control size (640x480 when disabled)
`isConnected`	Logical	`.F.`	Whether preview is currently active

Methods

Method	Description
`New( oWnd, nTop, nLeft, nWidth, nHeight, lInit, lAdjust, nRate, bError )`	Constructor. Creates the VFW capture window and optionally starts preview.
`Initialize()`	Connect the webcam driver and start the live preview.
`Finalize()`	Disconnect the webcam driver and stop the preview.
`SaveFile( cFileName )`	Capture the current frame to a BMP file. Defaults to a timestamp-based filename.
`VideoControl()`	Open the video source property dialog (brightness, contrast, etc.).
`VideoFormat()`	Open the video format dialog (resolution, color depth).
`StartCapture( cFile )`	Begin streaming capture to a video file.
`StopCapture()`	Stop any ongoing video capture.
`GetWidth()`	Return the current preview image width in pixels.
`GetHeight()`	Return the current preview image height in pixels.
`SetRate( nRate )`	Set the preview refresh rate in milliseconds.

Example: Live Preview with Capture

#include "FiveWin.ch"

function Main()

   local oWnd, oCam, lInit := .T.

   DEFINE WINDOW oWnd TITLE "Webcam Capture" ;
      SIZE 800, 600

   @ 10, 10 WEBCAM oCam OF oWnd SIZE 640, 480 INIT lInit

   @ 500, 10 BUTTON "&Snapshot" SIZE 60, 25 ;
      ACTION oCam:SaveFile( "snap.bmp" )

   @ 500, 80 BUTTON "&Format" SIZE 60, 25 ;
      ACTION oCam:VideoFormat()

   @ 500, 150 BUTTON "&Controls" SIZE 60, 25 ;
      ACTION oCam:VideoControl()

   @ 500, 220 BUTTON "&Close" SIZE 60, 25 ;
      ACTION oWnd:End()

   ACTIVATE WINDOW oWnd ;
      ON INIT oCam:Initialize() ;
      VALID ( oCam:Finalize(), .T. )

return nil

Notes