Emulate a screen capture card on your computer… for free!
September 2, 2008 by Victor · Leave a Comment
Have you ever wanted to use your video capture software of choice for creating screen captures, broadcasting live from your screen, or creating videos? Are you a software developer that would like to integrate screen capture into your software package? If your answer to one of these questions is “yes” then we have a solution for you… for free!
The solution is to use a free tiny (<1MB) utility called VH Screen Capture Driver by Hmelyoff Labs. VH Screen Capture driver works by emulating a video capture card in your Windows system, with the output being that of your local monitor. Think of it as a software-based frame grabber that works on Windows machines only. However, do not think of this software as complete replacement to frame grabbers, as it has many major disadvantages over its’ hardware counterparts.
First of all, the screen capture driver uses up a vast amount of system resources, meaning that more advanced applications will not have good capture quality, whereas a frame grabber uses its’ own resources only and puts no extra load on the system. The VH Screen Capture Driver is also only compatible with Windows machines and, being a DirectShow filter, will not work with all applications. A frame grabber however, is compatible with any VGA or DVI output, whether it be from a MAC, Windows machine, high-resolution navigational equipment, etc. Thus, VH Screen Capture is good as a free solution but in no way can this software match all of the advantages that frame grabbers entail.
Technically, however, VH Screen Capture Driver is a DirectShow filter and is compatible with applications that use DirectShow to display content on the user’s screen. The output frame rate does depend on which application is being captured and the system load.
In short, VH Screen Capture Driver allows the user to use popular video capture and broadcast applications, such as Windows Media Encoder and Adobe Premiere, without native screen capture support to grab the image off of their screen.
Using VH Screen Capture Driver
Step 1: Install the program and run it. You should immediately see the following screen. Press “create new one” to start a new instance of the capture driver.
Step 2: You will now see a configuration window. Under the “Capture” tab, you may choose the “Region” option and select only a region of the screen to broadcast. Ticking the “Track window” option enables you to broadcast a single application. You may select it by choosing it from the drop-down list or by clicking on the crosshairs beside the drop-down list and then selecting the application.
Step 3: Now select the “Settings” tab. Here you can adjust the maximum output frame rate, whether to show your cursor, or whether to compress the screen capture output. If you would like to resize your output in real time, the “Resize to output size” option must be ticked and the output size (Width/Height boxes) must be specified. This is most useful when you are broadcasting to the web and would like to limit the output video resolution in order to use less bandwidth or obtain a smaller file size.
Congratulations! The VH Screen Capture Driver is now configured. Now go to your video capture application of choice, select the “VH Screen Capture Driver” as an input, and start capturing!
