Sep 1, 2005 12:00 PM, By Jeff Sauer
Network video appliance encodes and decodes MPEG-4 for IP transmission.
By now, most AV contractors are aware of the trend toward using IP networks to move AV control data. And the advantages are fairly clear: unlimited distances, potential control from any device or browser anywhere, no need for dedicated wiring, etc. Moving audio and video media over IP can yield the same benefits and maybe a few more, yet video over IP has a reputation for bandwidth challenges and other technical issues. But it doesn't have to be that way.
Overcoming those obstacles is just what VBrick Systems has been doing for the last eight years. Its video appliances, like the recent VB6200 Network Video Applicance ($6,995) that I tested, turn standard video and audio sources into IP data and back again. (In the case of the VB6200, that IP data is in the form MPEG-4 — it's configured with an MPEG-4 decoder and encoder.) The user has to do little more than plug the device in. What has changed in the past eight years is that today's networks are more robust, bandwidth is far less a limiting factor, and VBrick's product line has grown to match a variety of configuration needs.
On the surface, the VB6200 is very similar to most VBrick products. In a nutshell, it's an MPEG-4 encoder and MPEG-4 hardware decoder in a black box. The VB6200 has a small LCD readout on the front and connectors on the back for S-Video, composite video (BNC), stereo audio, and an Ethernet port, plus a couple of COM ports for setup and legacy external control. Of course, you can control it over IP as well.
The VB6200 is an MPEG-4 encoder and decoder. VBrick also offers MPEG-2 and MPEG-1 versions to suit different needs in terms of bandwidth and video quality. There are even double-encoder configurations that include, for example, MPEG-4 and MPEG-2 realtime encoders. However, in VBrick's world, that's probably more about the technology than you really need to know.
IT SLICES, IT DICES
Naturally, the term “appliance” is no accident. Like a dishwasher or toaster, a VBrick has a fairly precise job and does it with minimal user interaction. In this case, that task is turning analog audio and video from a videocamera or other source into IP data and sending it over a network for viewing elsewhere, whether that's at the other side of an office building, across a school campus, or across the country.
Rather than getting bogged down with the technology, VBrick likes to talk about its appliances' output as television over IP or Ethernet television. Unlike the small frame sizes and shuttering typical of most “streaming” video, VBrick works with television-quality video. VBricks are regularly used for distance learning, or for sending high-quality video of a live lecture or training session to a remote location. They're used for always-on two-way video communications. They're also used for one-way visual monitoring, as with traffic congestion, military training exercises, or simply monitoring staging/rental programming from a remote control room.
The higher-bandwidth bit rates of MPEG-2 and even MPEG-1 typically require a properly switched LAN or WAN infrastructure. However, the introduction of low bit rate MPEG-4 VBricks like the VB6200 enable realtime video with reasonably good quality over the Internet, as well as over a LAN, provided the sender and receiver both have at least a broadband connection.
MPEG-4 tends to reach its maximum image quality at about 2Mbps, although it's most efficient in terms of quality/bit rate between about 450kbps and 1Mbps, assuming a standard profile, quarter-screen “SIF” resolution (352×240). That's the resolution limit of the VB6200.
Viewed on a television monitor zoomed up to full screen, the quality of MPEG-4 is similar to that of older MPEG-1 encoders, albeit at less than half the bit rate. Viewed in a window on a desktop, MPEG-4 looks very good. MPEG-4 can theoretically support higher bit rates and full-screen resolutions, but in the interest of open standards and compatibility with as many MPEG-4 decoders as possible (including desktop software players like QuickTime), VBrick does not.
I tested two VB6200s sending video back and forth over a LAN. I also had colleagues in other locations view the MPEG-4 streams at their desktops across the Internet, including from behind firewalls. That's possible because VBrick supports HTTP tunneling, and it makes the VB6200 very flexible. Also, thanks to a low-latency mode (less than a half a second), I established a VBrick-to-VBrick videoconference, also over the Internet. VBrick is quick to point out that VBricks aren't designed to make “calls” to traditional, legacy videoconferencing equipment. But unlike videoconferencing equipment they are always on, no calls are ever dropped, and the image quality over the Internet is comparable to that achieved over a dedicated line by videoconferencing.
Some minor network configuration is necessary to put a VBrick outside a local firewall, although it's nothing that I wasn't able to achieve (with a little help) within about five minutes. For local point-to-point, VBrick-to-VBrick video, configuration is even easier. For me, getting two VBricks unpacked, cabled up, set to accept a DHCP IP address, and moving realtime video took about a half hour. And most of that was the cabling!
The VB6200, like all VBricks, comes with a VCR-like IR remote that can be used with the front-panel LCD to quickly establish a default IP address or DHCP automatic address. Once you have the unit's IP address, you can access all of the configuration parameters from a browser interface, including video and audio bit rates, unicast or multicast setup, point-to-point destinations, and even picture-in-picture setup. What's more, everything is scriptable and programmable, for use with Crestron or AMX control systems — or simply make the buttons on the IR remote perform specific operations.
Users have plenty of options for custom settings. However, the majority of users should find useful VBrick's customizable encoding templates for different connection speeds. And there's a pulldown menu of every other VBrick on the network for quickly establishing those direct point-to-point video communications.
Although the MPEG-4-based VB6200 is a relatively new product, it functions almost exactly the same as VBrick's older products based on MPEG-2 and MPEG-1. The web interface hasn't changed, and neither has the physical chassis. That's no surprise, because encoding the video and audio works just the same, aside from the lower bit rates of MPEG-4. VBrick's issues have almost always been network-related. Fortunately, with the advances in routers, DHCP servers, and just pure available bandwidth, moving video and audio is getting to be almost as easy as moving control data.
Company: VBrick www.vbrick.com
Pros: Easy installation and setup, sends video and audio to any other device that can play a standard MPEG-4 file.
Cons: Price is high for an MPEG-4 encoder. No component jacks.
Applications: Monitoring, business training, distance learning.
Video format MPEG-4
Video bit rate Up to 2Mbps
Audio bit rate Up to 384kbps
Resolution Up to 352×240
Connection S-Video, BNC composite, 2X 1/8in. audio, Ethernet, 2X serial
Internet protocols RTP network, RTSP server
Connection protocols Unicast, multicast, RTSP, HTTP tunneling
Dimensions (H×W×D) 2.25"×8.675"×12.5"
Warranty 1 year standard limited warranty
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