Full Epiphan VGA2USB Review by Jonathan Adams
Epiphan's VGA2USB comes in as the very base model of their VGA frame grabber line, but it definitely has a lot to offer. The overall idea of this device is to record virtually any VGA video source onto a computer through the computer's USB port. The most common VGA sources would include computers, video game consoles, and some lab measurement equipment. If you have any video source that outputs a standard VGA signal, it can be viewed, captured (single screens), and recorded by this device. Using a Windows, Linux or Mac OS X based computer you view and record the incoming video feed.
First off, one of the most impressive aspects of the hardware to note is the size. The Epiphan VGA2USB adapter is roughly the size of a deck of playing cards. Physically the adapter has a very clean and simple design. The adapter itself has a 15 pin (DE-15) VGA connector on one side to connect to your VGA source. On the other side, it has a mini USB-B type port for connecting to the computer that will be recording the video signal. The side with the USB connector also has three notification LEDs: one for power, one for signal status, and one for capture status.
Here are some of the detailed hardware specifications as provided by Epiphan:
|Maximum Sample Rate: ||230 Mpixels per second|
|Color Resolution: ||16 bits per pixel / 5:6:5 format|
|Supported VGA Modes: ||640x350 at 60, 85Hz|
640x400 at 60, 85Hz
720x400 at 70, 85Hz
640x480 at 60, 70, 72, 75, 85Hz
800x600 at 56, 60, 70, 72, 75, 85Hz
1024x768 at 60, 70, 72, 75, 85Hz
1152x864 at 60, 70, 75, 85Hz
1152x900 at 66, 76Hz
1280x960 at 60, 85Hz
1280x1024 at 60, 70, 75, 85Hz
1600x1200 at 60, 65, 70, 75, 85Hz
1920x1200 at 60, 70, 72, 75, 85Hz
2048x1536 at 60, 70, 72, 75, 85Hz
Update Rate ||While results are typically around 10 updates per second, here are actual results under varying conditions:|
Resolution/Frame Rate:|| 640x480 / 28 fps|
800x600 / 20.6 fps
1024x768 / 10.0 fps
1280x1024 / 5.6 fps
1600x1200 / 4.3 fps
1920x1200 / 3.1 fps
2048x1536 / 2.0 fps
Video Format Options:||RGB plus HSync and VSync (5 wire)|
One very important thing to note about this model is the fact that it captures the images as interlaced images only. This means that only every other line of pixels is updated each time the device refreshes the image. This will cause some streaking to occur if an object is moving across the screen. It is very common for capture adapters of all sorts to capture video in an interlaced manner so it isn't much of a surprise to have it on this adapter also. This is probably the biggest difference between this model and the higher-end models that Epiphan has to offer, as the higher-end models provide a progressive capture instead of interlaced.
The software that is used with the Epiphan devices is a fairly simple, but effective tool. The same software is used for all of the various Epiphan frame grabber devices. Upon opening the software you are greeted with a very simple interface with very few buttons. This interface can be seen in the image below. As you'll notice, the window will display a status message if it cannot find the device, or if the device is not receiving a valid signal. That window simply changes to the video feed from your other device once it is connected properly.
While still simple, the software provides a fair amount of functionality and flexibility. There are buttons to provide instant access to save, print, or copy a snapshot to the clipboard, to start capturing, and pause capturing. The software has an options menu that allows you to set your video codec, file size limits, automatic record settings, and more.
This software is very easy to use and for basic capture needs it will do everything you need. If you need to integrate the capture adapter into your system and need more control, Epiphan provides an SDK for developing your own software solutions or for integrating their capture functionality into your existing software.
One thing to note is that the software is not included with the product, but must be downloaded from the web before attaching and using the device. These seems to be done to make sure that you get the latest version of the software before using the device. Fortunately, it is a fairly small download so it's not much to worry about there.
To help illustrate the image quality we've taken some samples of the capture quality of the adapter versus the quality of the image that is not going through the adapter. You'll notice that the image quality does change a little bit from resolution to resolution. 1024x768 seemed to provide the best color reproduction, but 1600x1200 was also very clean. 1280x1024 seemed to come through slightly washed out. Overall all of the images were very high quality and impressive for a capture at those fairly high resolutions. In each image the right half of the picture is the incoming feed through the VGA2USB adapter, while the left portion is the same image and text displayed on the computer itself.
As you can see, the Epiphan VGA2USB adapter provides a very high quality capture.
In testing we made a few video recordings at different resolutions. All of the videos came through very clearly and cleanly. We used the rotating logo found in Nvidia's video control panel to demonstrate the issues that come from the video interlacing that the adapter does. All of the videos we recorded were very similar in frame rate, but the size saved for each file varied a lot due to the differences in resolution.
These videos show how clear the video can be captured. They also show the problems that the interlacing can potentially cause if you are needing a more perfect reproduction of the video signal.
Let's go through some of the advantages of this system. The biggest advantage is the ease of installation and use. It doesn't take much expertise to be able to use this device. Anyone with any experience downloading a driver and running the installation program can install it. It really is as simple as installing the downloaded driver, plugging in the adapter, and running the software.
Another advantage is the flexibility that comes with the ability to integrate the software and its functionality into your own systems and software. This is something that a lot of other format capture cards and adapters don't provide support for, but this can be key to effectively using the adapters.
With the adapter being an external capture adapter you can easily move it from machine to machine without having to open the computers and install the adapters. This means that you can use fewer adapters in those applications where you need to capture to multiple computers. It also goes back to the ease of use, allowing people who are not familiar with the inside of a computer to still install them.
The fact that the adapter is fully bus powered can be a life saver. This way you can use the adapter without having to hunt for a power outlet. In some situations this may not be a big problem, but in situations where you're capturing to a laptop and are far from a power source. All in all it adds even more to the ease of use for this product.
Lastly, you have the advantage of price. This capture adapter is very reasonably priced for what it can do
There are a few features that would be nice to see, but considering that this is the base model product it's not surprising that they aren't there. They are good to keep in mind, however, as they may affect how well the adapter meets your needs.
As was mentioned in the product specs and seen in the video captures, this adapter only provides an interlaced video capture. This causes some distortion and things on things moving somewhat quickly across the screen. For taking screen shots, viewing video feeds that don't need to be recorded at perfect qualities, or for slow moving feeds this isn't much of a problem. It would be problematic if you were trying to get a perfect reproduction of a video signal that has much quick motion on it.
This particular model of the adapter only supports a VGA (RGBHV) type signal. For some scenarios it would be very helpful to be able to record component RGB or DVI signals.
Lastly, the recording frame rate at higher resolutions is a little lower on this adapter than some internal capture cards and the higher end Epiphan external adapters.
The Epiphan VGA2USB video grabber has proven to provide a lot for very little. For anyone needing a VGA capture solution, this is definitely worth looking into. It consistently and easily provided great video and image reproduction from a VGA source. While it does have the drawback of being an interlaced signal, it is an excellent solution in situations where the interlacing isn't a problem.
For the low price that these can be had for this is the best external VGA capture solution I've ever had the chance to use. I have been very surprised and pleased with the ease of use and performance of this adapter. It will be a great solution in almost every scenario.
If the issue of not supporting component, DVI, or it being interlaced is a problem for your situation check out Epiphan's higher end VGA and DVI video grabber models. They have a lot of options and they can provide you with the functionality that you need.