VGA together with its extensions are in the basis of nearly all video cards used in PCs. At the same time, video cards support color modes and resolutions which are far beyond what VGA really is. The VGA standard is used in a broad range of solutions applied in engineering, medicine, science, education, etc. For a variety of reasons most users that deal with this equipment need to be capable of capturing images. Time-critical tasks should be performed through the image processing. The images can be recorded, broadcasted to the web, viewed and edited remotely. Possibility to digitize the captured images is an important function for the users of the equipment. Final choice should be made depending on the used facilities and user’s purposes.
Video converters are at the lower end of the price range among the video capture solutions. VGA converters connect VGA output to the video input on your TV. VGA2Video from Svideo allows users to watch video from the computer synchronously on a TV and VGA monitor. PC-to-TV converter from Sewell provides the same functionality.
Converters and Graphic Boards
Among low-cost solutions for capturing video signal, you may choose a video card featuring video capture support. These cards are offered by all main manufacturers (Matrox, ATI, NVIDIA, ASUS, etc.). For example, an ATI Radeon VIVO graphic board features 3D resolutions (32-bit color) and 64 MB of video memory at a very competitive price. External conversion units ensure connecting analog video equipment to the computers and users can perform video editing operations. ADVC110 from Grass Valley can be connected to all digital and analog cameras. This unit requires no power supply and has no drivers to install.
Due to multiple reasons low-quality video capture may be not convenient for the users. For example, you may need to capture video from multi-camera systems with overall data rates more than 100MB/s or cameras with high data rates.
Internal and External Frame Grabbers
If VGA capture should be performed from military or scientific equipment just to name a few, high resolution rates and life-like quality are required. For these purposes frame grabbers are used. Frame grabbers are rather expensive solutions that provide VGA capture to USB. They capture video signal and convert it into a digital stream. There are a lot of VGA and DVI frame grabbers on the market, each with its advantages and disadvantages. Frame grabbers sometimes are more complex to operate than graphic boards and converters and perform a wide range of functions. There are internal and external frame grabbers on the market.
Internal frame grabbers are PCI cards fitted in the computer. They capture video signal through VGA port and convert it into a video file or a series of images. This content is then saved in a proper format. The VGA capture cards are usually supplied with specialized software and sometimes support third-party applications.
XtremeRGB-Ex1 by EMS-Imaging is a PCI-Express card that captures images either form VGA or DVI sources. It has input mode detection, supports seven RBG modes and features maximum analog RGB capture resolution of 2048×1536 and on-card processor for sync detection and real-time mode. Using a special option you can choose between transferring data to the card via system memory affecting performance or directly. Datapath VisionRGB-PRO1 captures the VGA output and displays it as an independent application. This card uses specialized dual-port video memory ensuring high performance. It captures data at maximum resolution 1600×1200. VGA-Master from PixelSmart is an internal PCI card featuring resolution up to 1280×1024. The card is supplied with its own software that allows snapping screenshots. The card supports Windows 2000. PC2-Vision Express from Dalsa is a PCIe image acquisition board. It interfaces with standard (RS-170 and CCIR), nonstandard (progressive scan), RGB and dual-channel analog cameras. PC2-Vision Express features six inputs and high digitization rates. Digitizer DCC 3.1 Card from NCast features VGA, DVI, S-Video and Composite Video inputs and works with both Windows 2000/XP and Linux PC desktops. TopDomain XI102AE video capture card allows saving captured data in different formats (WM9, REAL, MPEG4) and supports resolution up to 1920×1440. This PCI-E card supports multiple cards operation in a single PC and allows for streaming or broadcasting over PAL/NTSC network.
External frame grabbers are portable and standalone solutions providing VGA capture to USB. They can be connected to PCs via USB input or directly to the Ethernet. In this case users in remote locations can view the captured stream and record it on PC.
iPORT Connectivity Solution streams imaging or video data from analog cameras in real time over Ethernet. It converts the data to IP packets and pumps it onto the GigE link. Packets are transported continuously to PC connected to Ethernet. This device requires installing several software packages on the PC. Microvision’s MV-U2000 external frame grabber box is a portable USB color/monochrome frame grabber box with resolution up to 768×576. VRmFAVC-1OEM frame grabber from VRmagic is available both in internal and external versions and features 64 MB ring buffer to prevent loss of image data. Its maximum resolution is 720×576. VGA2USB frame grabber can capture signal from any VGA source – workstations running under Windows, Mac OS, Linux, different types of equipment featuring VGA output. VGA2USB supports 13 VGA modes with frame rates up to 28.0. It captures video at an extremely high resolution up to 2048×1536. VGA2USB software allows for viewing and saving captured data in a real time or copying captured data to a clipboard. VGA2USB is compatible with DirectShow on Windows and QuickTime on Mac OS X.
Making a Final Choice
When choosing an appropriate VGA capture solution you can take into account the following considerations. Decide for what purposes you will capture video signal. If the image resolution that video converters/capture video cards provide is satisfactory, don’t look for the expensive solutions. If you need a solution for capturing high-quality images, then take a look at frame grabbers.
Internal frame grabbers are suitable for consumer and home needs. Of course, they are not appropriate for the cases where portable equipment is preferred. You will have to open up the PC each time you need to install the device – it often causes concerns to end users.
You don’t need to modify a source device when installing a frame grabber. It provides total security of VGA capturing process. This equipment is ideal for tasks that require high levels of data reliability. It is broadly used for digital multimedia recording, webcasting, streaming media, security and surveillance, as well as remote viewing applications.
Source by Sonya Blade