May 7, 2002 4:00 AM PDT
Net video's obstacle to a steady stream
In the past few months, Microsoft, RealNetworks and Apple Computer have announced improvements to their streaming media systems that herald the end of cutouts and congestion in Net delivery of audio and video, or what's known as buffering.
For the most part, the advances are contingent on high-speed connections that allow viewers to take advantage of excess capacity, a solution that masks underlying delivery problems without fixing them. Even with these enhancements, analysts say, Internet video has a long way to go to match TV quality.
"A lot of the sins of streaming media can be made up for in a broadband environment," said Steve Vonder Haar, an analyst at Interactive Media Strategies, a research and consulting firm. But "even in a perfect world of broadband you have a potential for glitches that can mar the experience."
Solving quality and cost issues in Internet streaming is key to its viability as an entertainment medium capable of competing with other digital delivery platforms, such as cable TV.
Technology innovations in media players address a major piece of the puzzle in delivery of rich data such as video over IP (Internet Protocol), a method for sending data from one computer to another on the Internet. But the potential for delays and data jams on the Internet still exists.
In fact, one of the Web's greatest strengths can be thought of as its weakness when it comes to streaming media. The architecture of the Internet is designed to offer a set of redundant pathways for ferrying "packets" of content--if one byway is jammed, chunks of data can be zapped through another. Though it's a nearly flawless system for sending text, audio and video can suffer hiccups in the stream when they are broken up and rerouted.
Companies such as Exodus and Akamai Technologies have sought to improve data delivery by pushing content to the "edge" of a private network, where it's nearest to access. They essentially nudge content off the Internet to the fringes of a "wide-area network," close to where people want to access the data, reducing the chance of Internet congestion.
Still others, such as EdgeStream, offer software that focuses on the "middle mile," reducing packet loss and delays by intelligently routing data over the Net dynamically throughout each session.
Refining the system
Streaming media giants RealNetworks, Microsoft and Apple have taken a different approach, refining their media systems so they use excess bandwidth capacity to stuff data down the broadband pipe and store it locally. For example, someone streaming a file encoded at 300kbps over an 800kbps connection would have an extra 500kbps in bandwidth that could be used to temporarily store data that would be played back later on in the stream. The technique does not stop hiccups and delays; it merely keeps most from being passed through to the viewer.
RealNetworks in March introduced its TrueStream technology, which shears the lag time associated with audio and video streams for broadband users. Microsoft has talked about similar technology called FastStream for its upcoming media player, Corona, but the software giant has yet to introduce it commercially.
"When you have consumers connecting to view streaming media at higher bandwidth rates, or broadband, this changes everything," said Peggy Miles, president of Intervox.com, a Washington, D.C.-based digital media and communications company, and author of "Internet World's Guide to Webcasting/Broadcasting on the Net."
"You don't always use all the data that is available on bandwidth," she said. "Sometimes there is not much motion in the picture; when that is the case...there are extra bits that can be used to improve the quality of the pictures and predict the next frame or picture.
"RealNetworks or Microsoft can use those unchanging motion pictures to do nifty technical software tricks in the background that will improve the quality of an audio or video stream to the desktop," she added.
Still, the quality of these services largely hinges on high-speed connections, which make up a small piece of the Internet population. Up to 80 percent of the wired world still accesses the Internet through a dial-up modem.
A increase in the number of high-speed Net users would not necessarily boost interest in services that rely on excess bandwidth. To promote the adoption of broadband, Net access providers are matching consumers more closely with their speed needs through tiered pricing plans. For example, consumers who sign up for broadband services at speeds below 300kbps would not have excess bandwidth that could be used to smooth over streaming hiccups, giving them substantially fewer benefits from such features.
Ebbs and flows
Despite differences in their technologies, Apple, Microsoft and RealNetworks all are relying on people who pay for access to more bandwidth than they use.
QuickTime, Apple's multimedia server and player, which has become a big hit for viewing movie trailers, also includes "Skip Protection," which was introduced in October 2000 and enhanced in February. The technology "understands that there are variations in bandwidth while you're streaming, and it uses pyrotechnics to shift down to smaller video when bandwidth is constrained," said Frank Casanova, director of QuickTime product marketing at Apple. The technology fills up the buffer with content, so if bandwidth becomes constricted, it plays directly from the buffer or the cache. When it frees up again, the stream continues naturally.
"It ebbs and flows," Casanova said. "We re-sync everything, and the end user never knows what happens."
Microsoft's FastStream would be built into the player and the server, a benefit that it says would balance the load of content streams. "It's always-on streaming that actually enables a vast reduction of some of the effects of network congestion, so you get an unbroken experience," said Jonathan Usher, director of the Windows Digital Media Division at Microsoft.
The Corona media player, with FastStream, is expected to be released sometime later this year.
RealNetworks' TurboPlay is part of its premium service RealOne, which costs about $10 a month. The technology allows near-instant playback of audio and video for broadband users and speedy fast-forward features. The company says it improves performance by more than 800 percent on a corporate LAN (local area network) and by 600 percent through a DSL (digital subscriber line) connection. DSL on average streams at speeds of 256kbps and 384kbps.
"We look at the clip being sent, and if there is extra bandwidth, we take advantage of that to send more data faster," said Ryc Brownrigg, general manager of consumer software for RealNetworks.
Bandwidth to spare?
Rajeev Sehgal, vice president of business development for EdgeStream, said Microsoft's and RealNetworks' technologies work well only if there is bandwidth to spare in the user's connection, such as on corporate LANs, which link a group of computers together within a building. But he said the technologies typically fail over wide-area networks on the public Internet during peak usage periods.
The quality goes up when clips or videos are encoded at 300kbps or less and streamed over average broadband connections of around 800kbps to 1.5mbps. That leaves a large amount of excess capacity that can be used to jam more data down the pipe and help smooth over latency. But the encoding speed does nothing to fix the underlying problems of congestion on the public Internet.
"Current (content delivery networks) and edge delivery networks cannot even guarantee their customers 300kbps video streams because of congestion and latency," Sehgal said. He touted his company's technology as a big step forward. He said EdgeStream's intelligent routing can guarantee throughputs of up to 2mbps, where such speeds are supported by the ISP connection.
Whatever the solution, the streaming industry badly needs to overcome the buffering problem. RealNetworks, Microsoft and Apple have made vast improvements to their encoding and decoding technologies to deliver more content faster and in smaller files. But the adoption of broadband and the oncoming push for video-on-demand services have a way to go before the experience is flawless, analysts said.
"The people who are trying to sell streaming media as an entertainment application today are the same people who were trying to sell cellular phones to soccer moms 20 years ago," said Interactive Media Strategies' Vonder Haar. "Streaming media over time is going to transform the face of computing, but it's going to take some work to make it happen."