HOWTO: Specifying The Real-Time Video Source

XVa3 utilizes two different add-ons to enable the capture of images from real-time video sources: DirectVideo; QuickCam; and Real-Time Video .  The biggest difference between these add-ons is the type of driver that each utilizes in order to accomplish this task.  The RTV (real-time video) extension utilizes VFW (Video-For-Windows) drivers while DirectVideo utilizes DirectX/DirectShow/WDM drivers in order to open and capture images from video hardware (the QuickCam extension is to control the QuickCam camera directly).   Why should you care about the type of drivers utilized by each of these extensions?  Because under Windows 2000, most of the more popular video capture cards and devices are no longer supporting the VFW format (thus making them unusable with the RTV extension).   For this reason, most (if not all) users of XVa3 will be changing from using the RTV extension to the DirectVideo extension once they upgrade to Win2000.

 

How Do I Select Which Video Extension XVa3 Will Use When Capturing Video Images?

After you have downloaded and installed the DirectVideo extension to XVa3, you can select which video extension you want XVa3 to utilized by selecting Select Video Device Type from the Tools menu.

  
The type of video extension that XVa3 should utilizes is specified by selecting Select Video Device Type from the Tools menu.

 

Option

Description

Notes

DirectVideo

Captures video via DirectX / DirectShow / WDM video sources.

This is the recommended video capture selection for Win2000 computers

Real-Time Video

Captures video via Video-For-Windows video sources.

This is the older method of video capture and is not typically supported by newer generation video capture cards.

Quick-Cam Video

Captures video via the QuickCam hardware.

If you are using the QuickCam camera, it is highly recommended that you use this selection in order to get the most out of the QuickCam system.

Prompt before each capture

Prompts which extension should be used before each capture.

This setting should be utilized if you will be using more than one video device and those devices do not all support the same type of video API (e.g. VFW or DirectX).

 

 

How Can I Tell Which Extension I Am Using Once I Start Video Capture?

In order to distinguish between the different video capture extensions you are using under XVa3, the RTV and DirectVideo interfaces have a slightly different layout.  For more information on utilizing these interfaces, please refer to the appropriate on-line help reference located under Other Topics in the Help menu within XVa3.


The RTV extension’s interface.  

 


The DirectVideo extension’s interface.

 

 

What If I Need To Support More Than One Video Type?

Should you have more than one video device on your system (i.e. digital camera and a QuickCam system) and you need to be able to select which video extension you want to use before video capture, you should select the Prompt before each capture option from the Video Source dialog (please see the “How Do I Select …” section of this documentation.   When you go to capture video, you will be prompted to select which video extension should be used.


If you selected the Prompt before each capture option, you will be prompted to select which video extension you want to use hen capturing a video image.

 

 

What If My Video Device Is Not Listed Or Does Not Work Under My Current Video Extension Type?

If your video device is not listed under the Video Devices menu in the video extension that you have selected, then more than likely, that driver type does not support it.  If your video device is not listed, simply exit the current video capture, select the other video extension and then retry the operation.


If your video device is not listed under the Video Devices menu then it may not be supported by the selected extension.  Simply exit the current video capture and then retry the operation with the other extension.