Streaming Media

Streaming Media
03.25.03

By Warren Ernst

Streaming media can enhance your Web presence—and your bottom line. Let's look at the basics.

There are two types of streaming methods on the Internet: progressive and real-time. Each has its strengths and drawbacks, and each is suited to different types of material.

Progressive streams are sent to users via conventional Web servers such as Apache and Microsoft IIS. In fact, progressive streams are just "regular" files—such as MP3, QuickTime (MOV), RealMedia (RM), and MPEG video—which are designed to stream naturally. Such files can stream content because various media players, including QuickTime, RealOne Player, Winamp, and Windows Media Player, can start playing these files as they are being downloaded.

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Real-time streaming works with a streaming server software package, a matching streaming client, and a Real-Time Streaming Protocol (RTSP), which controls their interaction. The content is stored as files on a streaming server and is sent to remote users a few frames at a time. If you want to broadcast live (or almost-live) events across the Internet, you need real-time streaming.

There are several popular real-time streaming servers. QuickTime Streaming Server comes bundled with Mac OS X Server, while its open-source brother, Darwin Streaming Server, is available at no cost for the standard versions of Max OS X, Linux, Solaris 8, FreeBSD 3.5, and Windows NT Server 4.0 or Windows 2000 Server. Darwin specializes in QuickTime content but can also stream MPEG-4 and MP3 formats.

The Windows streaming media server comes with Windows 2000 Server and, not surprisingly, specializes in serving Windows Media content. RealNetwork's Helix Universal Server runs on Windows NT 4.0, 2000 Workstation or Server, and XP Pro; Linux kernel 2.4.18; Solaris 2.7 or higher; IBM AIX 4.3 or 5L; HP UX 11.0 or 11i; and Compaq Tru64 5.1. And Helix can serve QuickTime, Real, and Windows Media streams. This package can get expensive, however. An open-source initiative called the Helix Community project may make this technology less expensive by opening up source code and modules in the future. For streaming live audio content in MP3 format, the open-source Icecast server for Linux and Unix is your best bet, although any of the other streaming servers can also handle MP3s.

There are other factors to consider. For example, progressive streaming puts copies of your media on viewers' hard drives, so you lose control of third-party distribution. Packets lost because of Internet hiccups get retransmitted and can almost always get through firewalls. Because large files will eventually get to their destinations regardless of connection speeds, you can offer media with better picture quality with progressive streaming.

Real-time streaming offers random access within prerecorded media and places no files on viewers' hard drives. Real-time content also can't be saved or retransmitted and can adjust the data rate to match users' capabilities. Unfortunately, movies can stutter or break up if the connection is too slow.

Though you don't need to spend much to get a streaming server up and running (a 1-GHz PIII can carry dozens of concurrent streams and, as previously noted, many of the streaming servers are free), you'll probably need to upgrade your bandwidth to handle many concurrent users. With real-time streams, it takes only about 25 viewers using 56-Kbps modems to saturate a standard 1.5Mb T-1 line. Obviously, increasing your company's bandwidth can help, but it can get expensive. Outsourcing material to a streaming media supplier, such as StreamGuys () may be the way to go. StreamGuys charges $100 per month for streaming 24-Kbps content to 100 concurrent users or $1,200 a month for 400-Kbps content to 100 users.

A new generation of broadcast tools called distributed content delivery systems works by placing identical copies of media files on many networked PCs. When a user requests content, the player begins downloading different sections of the file from different machines at the same time, then stitches the pieces together. In most cases, the entire file must download before playback can begin, but playback quality typically is very high. Even better, because these systems spread the bandwidth load across an internal LAN or the Internet itself, bottlenecks are generally eliminated.

Solutions using this peer-to-peer approach, such as CenterSpan's C-StarOne (), Jibe's Edgeburst (), and Kontiki's Delivery Management System 2.0 (), promise to speed rich media downloads and reduce bandwidth costs. Such solutions typically include components for managing and securing digital content. So far, these solutions generally come with a hefty price tag. As with other innovations, however, the technology should filter down eventually and bring better content delivery to individuals and small businesses.

Warren Ernst is a computer consultant, author, and journalist in Sourthern California.