Houses of worship have added streaming video to their AV systems to provide real-time broadcasts of their services to secondary worship centers as well as to enhance the Sunday worship service, allowing even the people sitting in the very back row to feel like they have a front-row seat.
Streaming video is most commonly used as either an Internet broadcast channel, serving up recorded videos on demand, or as a real-time one-way or two-way communications tool for conferencing. It can be used for entertainment or education as well as for surveillance or collaboration. It can be opened up to the public at large or used within a private network. However, none of this can be done until the video is actually online and to do that it takes a streaming media encoder.
Sitting squarely in the intersection where A/V meets IT, streaming media encoders are network devices that reside between your switch or router and your firewall. They translate your video into IP packets that can travel across the local IP network and across the Internet. Streaming media encoders built for A/V also scale the video for a specific output resolution, either low or high, which can be viewed on a variety of screens and across different bandwidths. For instance, you might want your on-demand video to be viewed easily by people using smartphones on a 3G network. However, you might also want the CEO’s quarterly message to stakeholders be broadcast in HD on a room-sized display.
No matter what kind of video you plan to stream, the streaming media encoder should share common features with other devices on your IP network.
“Reliability of service, ease of use and flexibility in configuration are top considerations. It’s just not important how good the stream looks if it goes down in the middle of an event. Also [important is] that the device will support the desired target and source formats. Some current units might not be able to support a 1080p signal,” says Ron Guensche, a live sound engineer and a network engineer at ednet (Entertainment Digital Network), a live audio and video webcasting production and streaming services company in San Francisco.
According to Guensche, input configuration is a top concern when choosing a streaming media encoder. “How easily does the unit integrate into your existing infrastructure? For instance, [it might] lack serial digital inputs, which a lot of facilities in my niche use, but [it might] have analog VGA inputs, which virtually none of the facilities in my niche use,” he says.
In the corporate world, streaming video is used for everything from demonstrating products to potential customers, providing detailed tech support, disseminating internal messages, and conducting meetings across continents.
Depending on your AV set up, you can plug additional devices into a streaming media encoder, such as a projector, a videoconference codec, display monitors, or a DVD player or other source devices.
“There are lots of encoders that are designed for use with standards based video formats from cameras. But from the AV perspective, you need products that can switch and process a wider range of signal formats and resolutions with audio and get them onto the network in a useable format,” explains Karl Johnson, director of Product Marketing at Extron Electronics, a manufacturer of A/V system integration products, including streaming media encoders.
“An A/V streaming media encoder will support a variety of signals that originate from computers or A/V devices that output a computer-like signal in addition to standard video signals,” says Johnson. These signals include S-video, standard definition composite and component video as well as Digital Video Interface (DVI) computer-video and HD.
As with all things IP networks, it’s important to stick with industry standards. Standards-based products play nicely with each other, including devices already installed on your network. They also help guard against vendor lock-in, which is important if you’re building you’re A/V system in phases.
There aren’t many industry standards governing streaming video, but there are two that all streaming media encoders must support: H.264, the standard for video compression and the most commonly used format for recording, compressing and distributing HD video, and MPEG-4, a method of defining compression of A/V digital data.
“Avoid using non-standard formats requiring specialized client software. Use H.264 where possible — all of today’s devices can decode H.264,” says Douglas E. Marlowe, principal at teachITnow, a visual communications and technical education consulting firm in Boynton Beach, Florida.
Of course, the point of a streaming media encoder is to stream videos over the Internet. The trick is to create the best possible output — videos — within the constraints of the network.
“Determine the best trade-off between stream stability and quality for the bandwidth you have at your disposal. For this type of product, this will take the form of which codec and bitrate to choose,” advises Guensche.
He likes a streaming media encoder that has separate control over video and audio codecs, saying, “I’m firmly of the opinion that audio quality is more important than video quality for an A/V stream.”
Many streaming media encoders designed for A/V take the form of network appliances. As networking components rather than strictly A/V devices, they come with a particular set of challenges for the A/V professional. As Extron’s Johnson points out, many A/V people are experts at projectors and signaling, but aren’t equally knowledgeable about IP networking and security, compression and other technical aspects of streaming over the Internet.
“The most common issues we see in the operation of any IP-based encoder are, on the user side, firewall issues. Also, a lack of understanding of how these devices reduce quality to stuff a big stream down a small pipe, and how to minimize the resulting artifacts,” explains Guensche. He points out that ednet has also run into difficult user interfaces on streaming media encoders as well as weak hardware builds, poor product documentation and badly implemented features.
When it’s time to buy a streaming media encoder, an organization’s plans for streaming video should guide that decision. Marlowe’s advice is to first define the input — is it a live event you’re streaming or a pre-recorded video? — and then define the output, remembering that people will watch your videos on everything from an enormous HD TV screen to a tiny smartphone. Cost is also a consideration, of course.
“You have the NewTek TriCaster 850 Extreme and the Sony Anycast and the Extron SME 100. We’re talking in the tens of thousands of dollars for these solutions,” says Marlowe. He points out that PC and Mac software solutions are available, but aren’t as rigorous as hardware-based appliances, such as those from vendors like Extron and Viewcast, and don’t last long when set up and torn down at live events. In fact, Viewcast offers streaming appliances that are designed to either live on the network or travel around the world.
“Generally speaking though, the most important element is you can’t fight the principle of garbage-in-garbage-out. To get the best quality output of any streaming media encoder, you need to start with the highest quality signal on the way in. This goes all the way to having good lighting, video and sound equipment, as well as skilled operators behind it at the source,” says Guensche.