Originally posted to Corporate Tech Decisions Magazine - April 29, 2013
Live Web streaming. If you mentioned these words only a few years ago, you would receive only a blank stare in return. Today's major product unveilings: Apple’s QuickTime series of products, Microsoft’s Internet Information Services media platform, and Adobe Media Server 5 are available and produce high-quality content. The result is that rather than traveling to attend a live broadcast, now people can attend right from their desks.
Streaming technologies are fast replacing the broadcast truck and satellite uplink for many meeting events looking to reach a national or global audience live. While Web streaming technology is not very new, its implementation in the event staging world is still emerging, and many users may be unfamiliar with the technology. However, on first look the technology and concepts for webcasting will feel familiar to most video-savvy people.
So What is a Web Stream Anyway?
The simple answer is that it is video pushed out to an Ethernet LAN (local area network) / WAN (wide area network) or the Internet. Streaming is a transport medium that converts incoming video sources into a signal you can send across standard Ethernet networks. However, to get the video into an acceptable format, you need to modify it a bit.
The first step is to pass the incoming video, graphics, and audio through an encoder. This device converts the signal into a format that software players can handle. The encoded signal now needs to be molded or packetized in such a way that it can be received by a player looking like a single unbroken stream. Packetizing means the video and audio are not just digitized into a scheme of ones and zeros but that the output of the media encoder, often called the elementary stream, is divided into data packets of encapsulated sequential data. What this means is that the live video is converted into a digital format that an endpoint player can receive and reassemble in a logical flow as an orderly video.
Think of it like the old Pneumatic tubes business used to transport mail between floors. Because the system used bullet-shaped containers pushed by a cushion of air through the tubes, the mail often needed to be carefully bent to fit; the process of packetizing is a bit like this, only with thousands of mail a second arriving on your desk.
Unfortunately, the video squeezed into the transmittable container is still too large for all but the most robust and dedicated networks. In order to get your video from one location to the next without compromising an entire data infrastructure bandwidth or that “real-time” feel, the signal must be made smaller. Continuing with the pneumatic tubes example, think of this as reducing the mail to be small enough to fit comfortably in the containers. The compression of
The signal does degrade the image quality a bit, and here we have a balancing act of making the stream small enough to be sent and received in a timely manner with the quality of video “resolution.” This is a delicate balance. If too much compression is applied, the resulting signal can be unwatchable, the display size is too small, and networks may not be able to deliver the stream in a consistent manner.
Now that we have squeezed, molded, and stuffed the video into a deliverable product, we will have to undo it all at the receiving end. Once the video arrives at a destination, the software player has built-in tools to decompress the stream and decode the signal. In general, most computer media players have the ability to handle a good majority of the standard formats, such as Flash (as used by YouTube), Windows Media files (WMA), and H.264 (MPEG-4). There are some exceptions though, and depending a need for encryption security or level of high-quality video, a plug-in or proprietary player may be required.
Data Movement on the Network
Most of us have at least a thirty thousand-foot view of how the Internet works. It consists of multiple servers and data switchers distributed across the globe, which we access via Internet Service Providers (or ISPs) such as a cable company or DSL. ISPs allow for simple, relatively quick, and mostly reliable service. Therein lays the rub. When connecting to a news page, a search engine, your local restaurant’s website, or even the cat videos on YouTube, the relatively quick and mostly reliable service is pretty much all you need. For the most part we do not notice the fluctuating download rates or are only mildly annoyed if we have to refresh a Web page to reconnect.
When it comes to a live-streaming video of your presentation, such burps and blips are not what you want, and they can be downright devastating. There is no guarantee of the reliability of the network that the audience watching the show is using, but you can maximize the stability and availability of the content being delivered. Like the old adage of “garbage in equals garbage out,” we want to ensure we provide quality as far down the line as we can. This is where Content Delivery Networks (CDN) come in.
CDNs are just what the name says — a dedicated cluster of servers spread across multiple regions or locations that relay content such as Web objects downloads, applications, and streaming services from the source with reduced bandwidth costs and generally increased availability. A CDN network consists of thousands of nodes and an exponential number of servers providing the content to viewers via localized relay sites using what is called Point of Presence or PoPs. PoPs work to increase speed and reliability by delivering the media from a location nearest to the viewer rather than directly from the source, thereby distributing the workload and reducing delays or latency that would occur if a player were connected directly to the source location.
Now that we have an outline of the transmission flow, you need to understand how the venue you choose can affect what you can do.
What You Need from the Venue
Clients and their designers choose venues based on a number of needs, including location, ability to accommodate the expected number of attendees, and aesthetics, but usually last on the list are the items that concern users the most. The technical capabilities of a building are often taken for granted, the thought being that if the venue is willing to accept a show, it must have all the requirements. This blissful attitude is doubly so when it comes to the Ethernet network. In most people’s mind an Ethernet network is just that like white bread in the grocery store, it is the same no matter where you go. I just heard a collective sigh of “if only” from the AV/IT community.
The reality is far more disconcerting. The reliability and consistency of many presentation venues can be compromised by various factors, from poor design and maintenance to a fudging of the numbers. So, what do you need to know when verifying that a venue can support your need for a streamed broadcast? The first question a Web streaming company you hire will ask is how many people outside the venue will be expected to watch some
or all of the event. The question may seem irrelevant at first, but it is an essential one. Knowing the total anticipated viewership helps to calculate the viewer stream hours (VST). This number, the VST, will determine the minimum upload speeds the network will require. Making sure your vendor goes over this number with you is important as it will also affect the total cost. More viewers means more CDNs and more resources. Finding the VST involves a basic formula (Number of viewers x the bit rate (quality bandwidth) = VST).In the pneumatic tube example, if the network of tubes is not maintained well or has complicated bends or turns, the mail department cannot send the letters in an expedient manner. This is also true for a venue’s Ethernet network or backbone. Asking and confirming the quality of the origination backbone (OG) is essential. If the network or providing ISP has issues or inconsistencies, it will be big trouble for your streaming.
If you find that the backbone is fine, the next concern is network speed. Most ISPs, when advertising their quality of service, will tout download speeds, and while this is very important to the average home or business user for getting files, pages, or other content from the Web, the concern here is the upspeed. Not all ISPs treat the ability to upload the same and, in many cases, deliberately throttle the upload speeds and charge more, sometimes much more, for faster service. In some cases, ISP up speeds can be half to a third of the rated download speeds. In streaming from our event venue to viewers webcasting is only concerned with the up speed, to be caught short could result in limiting the number of viewers, locations and quality of video. If at all possible, a minimum speed of 5 Mbits / second is recommended.
A lot of our discussion here has concerned the tools and processes to make a Web streamed video event stable and consistent. A static IP address for the streaming equipment is very important as well. Many large networks use Dynamic Host Configuration Protocol (DHCP) addressing, which automatically doles out or deactivates IP addresses from a table as needed or per a lease time rule. While broadcasting a Web stream upload via a DHCP address is not tragic, ensuring the system is using a static address can help make sure that any network rules or lease time issues will not interrupt the transmission.
If only you could eliminate the cable, life would be so much easier. Do not, I repeat, do NOT use a wireless connection as the connection between the transmission rack and the ISP. An oft-repeated and sage commentary on Wi-Fi communication holds true that the wireless transmission of data is the single most convenient method of connecting to date, yet it is also the single most unreliable method ever concocted. Wireless, especially Wi-Fi, is highly unregulated and is, by extension, extremely congested. In even minor urban areas, the number of Wi-Fi routers, access points, and devices such as computers, tablets, and smartphones is awe-inspiring. All of this congestion means that the number of possible sources of interference is infinite, and the likelihood of causing disruption to your show stream is just too high.
Why Go Pro?
At this point, you might be saying to yourself, “This all seems very complicated and requires a vendor to provide the service. My kids use Ustream and YouTube to stream to their friends — why can’t I use them too?” The truth is you could, and services like Ustream, Stickcam, Bit Gravity, and the rest provide great service and tools. This may be a fair option for some shows, but beware that they also have some pitfalls.
As with anything free or cheap, you have to ask yourself how the service provider makes its money and why it is free? Many online portals generate revenue by providing only standard-definition video unless you purchase a pro package. They also make money from ads. Often, ads are placed in your stream every so many viewer hours, and you do not get to choose the ads. Imagine your competitor's ad coming up during your show. These services offer rates that eliminate the ads, but most are yearly plans, so an ad-free, two-hour presentation will cost you a year’s subscription.
Hiring a professional webcasting vendor ensures that you will have a fully vetted system, venue and assured CDN’s. A professional vendor will also have the skill to help resolve any issues that may pop up anywhere down the transmission path.
Providing your viewers with the option of a presentation webcast opens new doors of revenue for your business, creative flexibility, and extended reach for the viewer. A little understanding of the mechanics can go a long way
