VGA2USB - VGA signal frame grabber.
VGA (Video Graphics Array) signal standard was developed and implemented by IBM in 1988. While initially it only supported 640×480 pixels resolution - it was quickly
superceded by more advanced standards (XVGA, SVGA and others) supporting much higher resolutions.
Wide acceptance of D-SUB 15 pin socket and connector helped to create unified platform to connect virtually any device with VGA output to any monitor.
Since then millions of computers, and specialized equipment such as handheld devices, radars, navigation devices, high resolution security cameras and medical devices such as ultrasound machines are using VGA signals to send information to be displayed on their monitors. Considering the huge number of devices that are utilizing VGA outputs there are surprisingly small number of solutions that would allow to capture and record VGA signal. This usually not a problem for standard computer equipped Linux, Windows or MacOS systems - these platform has plenty of software based video capture solutions. Although in the case where you are not allowed to access, install software or modify current setup of your computer - usage of any software solutions is out of question. Same situation applies to any internal hardware solution - such as PCI frame grabbers or video capture boards. For non-PC or non standard closed hardware device the problem of capturing and recording video becomes even more severe. Typical requirement within number of industries - is the need to record and save sequence of images that are displayed on the monitor for the purpose of archiving, training, security and other needs.
Epiphan Systems based in Ottawa, Canada filled this niche market with the range of specialized VGA signal capture devices. VGA2USB is the name of the most popular line of devices addressing needs of VGA signal capture and recording.
VGA2USB device is about the size of a paperclip box capable of processing VGA video stream and sending it via standard USB 2.0 cable to any computer for capture and recording.
Here's is how it works:
- Install VGA2USB software on the target computer (used for capture of still images or recorded movie sequences).
- Connect VGA output of your source device to VGA2USB box.
- Connect USB output of VGA2USB device to USB 2.0 port of your computer
- Start capturing and recording! No power supply is even needed - VGA2USB draws current from the attached USB 2.0 cable.
Since it introduction few years ago VGA2USB device found it's application within wide range of industries including healthcare, military, security, government and research fields. VGA2USB device shipped with the special VGA splitter cable allowing simultaneous connection of your monitor and frame grabber device.
VGA2USB device supports different flavors of Linux as well as Windows and MacOS operating systems.
Here is a list of supported resolutions and typically achievable (approximate) frame rates:
720×400 at 70, 85Hz
640×480 at 60, 70, 72, 75, 85Hz ~ 28 fps
800×600 at 56, 60, 70, 72, 75, 85Hz ~ 20.6 fps
1024×768 at 60, 70, 72, 75, 85Hz ~ 10 fps
1152×864 at 60, 70, 75, 85Hz
1152×900 at 66, 76Hz
1280×960 at 60, 85Hz ~ 5.6 fps
1280×1024 at 60, 70, 75, 85Hz ~ 5.6 fps
1600×1200 at 60, 65, 70, 75, 85Hz ~ 4.3 fps
1920×1200 at 60, 70, 72, 75, 85Hz ~ 3.1 fps
2048×1536 at 60, 70, 72, 75, 85Hz ~ 2 fps.
While 2-5 fps might not be sufficient to capture images of dynamic interactive computer game - this speed is quite satisfactory for many real scientific and industrial applications. Higher end version of VGA2USB - LR, HR and Pro deliver much better lossless compression and capture frame rate, than base model (shown in red color).
VGA2USB device shipped together with necessary software (to prepare target computer for capturing) as well as with SDK for custom applications.
Included software will install the program named "VGA2USB" that will assist in video stream capture process. It is possible to save single snapshots as separate images (JPG, PNG and JPG) as well as capture the whole movie. Codec for video capture can be selected from the list of installed codecs.
Here is a little hard to find secret: for the best video capture results Epiphan Development team recommends usage of VirtualDub application and K-Lite codec pack. This combo will allow to properly utilize threads in multicore processors and improve performance and final results.
VGA2USB driver has implemented WDM capability and recognized by system as "VGA2USB by Epiphan Systems Inc." imaging device. It is Direct Show compatible and you can use VGA2USB with any DirectShow enabled application using WDM Streaming interface.
Latest version of drivers can always be downloaded from Epiphan Systems website and supports compression to speed up frame transfer over USB. Compression works only with VGA2USB-PRO, VGA2USB-LR and VGA2USB-HR devices. Because FPGA and 16MB RAM lossless compression is performed on board with normal utilization USB bus bandwidth, VGA2USB LR can achieve 1280 x 1024
lossless compression with at least 30 fps.
Compression ratio depends on properties of the captured data (less motion in video - higher compression/frame rate) and performance of your workstation.
VGA2USB capture software also allows to set and change multitude of parameters such as Sampling Phase, PLL adjustment, Horizontal and Vertical Shift, Offset, Gain and many others. Software is contantly improved by Epiphan Systems and new features are added as market demands.
