xVideo 1.0 CW Manual

Copyright (c) 1999 by The Network Connection, Inc.
All Rights Reserved

What is xVideo Video Capture?

xVideo is an ActiveX Server Control that interfaces with Window's built in video API's. This control greatly simplifies the use of real time video and allows you to capture still images from the live video stream.

A demonstration copy of xVideo can be downloaded from http://www.olis.com/cw. 

General Requirements

• Windows 95/98 or Windows NT 4.0+.
• A Windows Video Input Device, such as a camera, video capture device, etc.
• Clarion for Windows version 4.0, 5.0.

Getting Started

Download and install the xVideo demo file. The xVideo.OCX file will be installed and registered in your windows\system directory. A demo CW 5 application will be installed in "C:\Program Files\xVideo". If you need to install the controls on your customer's computer, it is recommended that you use our install, as it installs and registers all needed controls and dlls.

Using xVideo

To use xVideo in a CW application, you must create a 32 bit application and place an instance of the xVideo control on your CW form. Follow the steps below to accomplish this.

• With a CW form displayed select the OLE Control from the Toolbox. Move the curser over the form and place the control on the from by dragging the mouse.
• Right click on the OLE Control and select properties. Check the 32-bit box and select the Ocx radio button. From the Object Type pull down select xVideo.xView. The Ole Property form show look like this:

Sample CW Application

xVideo is shipped with a sample CW Application that allows you to view and capture live video directly from a Window in your CW Program. The application consists of the following files:

xVideo.App - CW 5 Demo Application
xVideo.Exe - Compiled CW 5 Demo

When using ActiveX controls in CW, there are three ways to make the ActiveX server do something. You can read a property, set a property and call a method. Most ActiveX controls use methods with parameters. In CW this presents a problem because the syntax is very difficult to code when calling methods with parameters. In our custom written controls for CW, we have converted all methods with parameters to properties.

Most ActiveX controls talk back to their host programs using Events. In CW, Events are a real pain to code, so we have converted all events to the error property. After setting a property or calling a method that could produce an error, you can check the ErrorNum property to see if an error occured.

CW ActiveX Syntax

Property and Method Syntax	CW Example
Read a Property	Value=?OLE{'PropertyName'}
Set a Property	?OLE{'PropertyName'}=Value
Call a Method	?OLE{'MethodName'}

Object Reference

xVideo Properties

Property and Type	Comments
ErrorNum as Integer	Read Only. Check this property for errors.
ErrorDesc as String	Read Only. Description of Error.
DisplayWidth as Integer	Width of Video Display Box in pixels.
DisplayHeight as Integer	Height of Video Display Box in pixels.
StretchPreview as Boolean	Write Only. True-Causes the video image to fill the entire display box. This has NO effect on the captured image.
Preview as Boolean	Write Only. True-Causes the display box to show live video.
PreviewRate as Integer	Write Only. Frame rate per second. Valid range 1-100. Default=15.
NumberDrivers as Integer	Read Only. The number of known Windows video input devices attached to the PC. When 0 there are no valid devices.
SetDriverNumber as Integer	Write Only. Select video input device. This is a zero based selection. For example, if NumberDrivers returns 2, then valid devices are 0 and 1.
DriverNumber as Integer	Write Only. Select video driver to query. This must be set before using DriverName or DriverVersion. This is a zero based selection. For example, if NumberDrivers returns 2, then valid devices are 0 and 1.
DriverName as String	Read Only. Returns video capture driver name set with DriverNumber.
DriverVersion as String	Read Only. Returns video capture driver version set with DriverNumber.
CaptureToBmp as String.	Write Only. Captures video frame to a BMP file. If no file extension is given, then .BMP will be used. Check ErrorNum after setting this property.
CaptureToJpg as String	Write Only. Captures video frame to a JPG file. If no file extension is given, then .JPG will be used. Check ErrorNum after setting this property.
LastFile as String	Read Only. Complete file name of last captured file.
HasDlgDisplay as Boolean	Read Only. Video Driver has Display Dialog.
HasDlgFormat as Boolean	Read Only. Video Driver has Format Dialog.
HasDlgSource as Boolean	Read Only. Video Driver has Source Dialog.
ShowDlgVideoDisplay as Boolean	Read Only. Show video driver Display Dialog. False if error.
ShowDlgVideoFormat as Boolean	Read Only. Show video driver Format Dialog. False if error.
ShowDlgVideoSource as Boolean	Read Only. Show video driver Source Dialog. False if error.
Optional AVI Properties
AviTimeLimit as Integer	Max time in seconds to record AVI file. (Default=15)
AviCapture as String	Captures Live Video and Audio to a AVI file. If no file extension is given, then .AVI will be used. Check ErrorNum after setting this property.
AviCaptureRate as Integer	AVI frame capture rate. (Default=30 frames/second)
AviConfirm as Boolean	Write Only. If true a confirmation dialog will display before capturing AVI file.
AviHasAudio as Boolean	Read Only. Audio Driver has Format Dialog.
AVIShowDlgAudioFormat as Boolean	Read Only. Show audio driver Display Dialog. False if error.

xVideo Methods

Method Name	Comments
About	Show registration and version dialog.
CaptureToClipboard	Captures video frame to Windows clipboard.