A Buyer's Guide to Portable Encoders
Finally, because these programs are installed on general-purpose computers, operations as innocent as installing another program can degrade performance or even cause the program to crash or become unstable. For these reasons, many streaming professionals prefer portable streaming appliances over software encoders.
Portable Hardware Encoders
Portable hardware encoders come in an array of shapes, sizes, and price points, and most operate very similarly. Specifically, you can configure encoding profiles and server connection points in your office so that users in the field just need to power the unit up, achieve network connectivity, connect the camera, and press the encode button.
If there are problems, typically you can log into the unit remotely via its IP address, assuming there are no firewalls in the way. Many of these systems are actual computers running Windows or Linux, with graphics and USB ports. If you bring a keyboard and monitor along, you can configure the unit directly on-site. Since these systems are not used for general-purpose computing, they're more reliable and consistent (though they're much more expensive than your software-only options).
How to choose between the many options? A few simple rules will help narrow your selection. First, if you're working within a certain environment, such as Sonic Foundry's Mediasite, or VBrick Systems' VEMS Mystro, you should buy an encoder from that vendor. General-purpose encoders either won't work or won't offer the same level of integration.
One environmental factor to consider is noise. Because many of these systems are fully functioning computers in a small metal box, they need robust cooling systems that make the units too noisy to place anywhere near the action. If you're broadcasting a basketball game, system noise probably doesn't matter, but if you're streaming a quiet meeting from a small conference room, noise may be a problem.
Another factor is the availability of a touchscreen for monitoring and control. Keyboard and monitor connections are nice, as is the ability to configure the system remotely, but embedded touchscreens are just as good, though typically they carry a significant price premium.
Beyond this, focus on the connectivity and functionality you need the unit to provide. Most vendors in this space offer multiple options with varying video connections (SD analog, component, HDMI, HD-SDI), format support (Flash, Windows Media, HLS), resolutions (HD, SD) and stream count. By the time you identify and price all the units that meet your unique requirements, there probably won't be more than two or three candidates to choose from.
One capability you can't get from either software programs or portable hardware encoders is true portability; if you're moving the camera to follow the action, you need an on-camera encoder or a portable encoder with a handle that makes it easy to carry. Such systems really came into their own over the last few years, and this market should grow rapidly over the next few years.
At a high level, there are two types of on-camera encoders: stand-alone encoders that support Wi-Fi and Ethernet connections on-board, most with a USB port available for 4G modems, and integrated devices that enable both H.264 encoding and 4G cellular connectivity, usually via multiple 3G/4G modems. In addition, many stand-alone H.264 encoders have sister products solely for 4G connectivity. I'll confine my discussion to the encoding only class, but I will say that if you're looking for encoding and 4G connectivity, either buy an integrated encoder/4G connectivity product or purchase sister encoder/connectivity products from the same vendor.
As with hardware encoders, most on-camera encoder vendors offer multiple products differentiated by camera connection. As you'd expect, you'll pay more for HD-SDI connectivity than simple analog in. Virtually all on-camera products are single-stream-only, so there's little difference there.
Battery configuration and life is probably the most important configuration option. If your events are relatively short, any battery configuration will do, but if they're longer, units with internal lithium ion batteries tend to last longer than those that use external batteries. Of course, for really long events, it's nice to be able to switch external batteries even if it does require a stream switch. There are some larger encoder/4G modem products with external batteries that are hot-swappable, so you won't have to shut down to switch batteries. However, these are generally much larger than on-camera products.
This article appears in the forthcoming 2013 Streaming Media Industry Sourcebook.
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