Streaming Media - 09 Feb 2000

Microsoft and RealNetworks steal the show

Thanks to Internet technologies, you can now use your network to deliver quality video and audio to your desktops. As a result, you can bring training and corporate announcements to users in new and powerful ways.

Streaming video and audio have been available over the Internet for years and have become fairly stable technologies. The streaming-media market once boasted many players, but Microsoft and RealNetworks have bought out most other competitors. Despite nearly all Windows users already having the Windows Media Player (the Microsoft client for streaming media) on their system, RealNetworks remains a strong competitor with a powerful product.

In this comparative review, I analyze Microsoft Windows Media Services 4.1 and RealNetworks' RealServer 6.1. In examining these products, I cover two major functions: administration and content creation. Content creation proved to be the most complex and interesting category. Good content tools, such as programs for encoding video and adding titling, need to be accessible to users who don't want to learn about the details of compression schemes and network management. Content tools also need to let knowledgeable users control the encoding process, simplify video deployment to given locations on the server, and let users automate processes that they perform frequently.

In addition to offering classic on-demand streaming, both products let you set up a live broadcast (i.e., stream a live video feed out to your network), which you might use for important corporate announcements. In such cases, you would want to use one of the many multicast standards (e.g., IP Multicast)—if you have the network hardware to support it—so your network utilization doesn't become unreasonable.

Today, streaming media involves more than video and audio. Both products let you create synchronized presentations of text and graphics and stream them over very low bit rates instead of sending Microsoft PowerPoint files. Windows Media Services, for example, offers a PowerPoint add-in that lets you convert PowerPoint files to streaming formats so that the audience can watch the presentation progress without intervention while you control the flow.

Streaming video is one of the more bandwidth-intensive operations you can perform on a network. When you send video, you can appreciate the benefit of a network feature such as full-duplex operation (an Ethernet feature that improves the performance of streaming video), which might not typically affect your performance. If you're considering a move to 100Mb Ethernet, streaming video is a good reason to make the move. Full duplex operation reduces Ethernet collisions, thereby benefiting streaming video significantly.

I tested the products on a Gateway ALR 9200 with four 400MHz Pentium II Xeon processors, 512MB of RAM, and a 16GB SCSI RAID array. This system handled whatever I threw at it. Encoding performance, typically a torturously long process, wasn't worth measuring. My test video consisted of 38 seconds of a speaker at a presentation. The 260MB raw video file was 320 * 240 at 30 frames per second. Even before compression, local video playback on my monster server looked great. Uncompressed, this data would take 6.8MBps to stream in 38 seconds. However, uncompressed video is impractical in real-world situations.

RealNetworks is a prestigious streaming-media company. And, unlike Microsoft, RealNetworks charges you for its product. The fact that people pay for the company's product, despite Microsoft's omnipresent solution, is a good indicator of RealServer's value. RealNetworks' marketing appeal is a result of the company's products supporting OSs besides Windows NT, including Windows 95 and various UNIX versions. On NT, RealServer's features are powerful and fairly easy to use.

RealServer's pricing, which the company bases primarily on bandwidth usage, is complex. The free RealServer Basic handles low capacities. RealServer Plus costs $1995 and can handle about a T1 worth of data. The company targets RealServer Professional at LAN bandwidth. A 100-user license costs $5000, and a 200-user license costs $8000. In addition to differences in capacity, the Plus and Professional versions offer extra features, such as extended reporting and multicast capabilities. (For a comparison of features, go to http://www.realnetworks.com/products/servers/comparison.html.)

RealServer's primary development tools are RealProducer, which is free, and RealProducer Plus, which costs $149.95. The Plus version contains extra features, printed documentation, and a CD-ROM that contains the product.

RealSlideshow, which is free, and RealSlideshow Plus, which costs $29.99, let you create Web-based slide shows that you can stream from your RealServer system. The Plus version adds text captioning and layout tools. RealPlayer, which is free, and RealPlayer Plus, which costs $29.99, are the client products. The Plus version offers features that let you manipulate music, including a 10-band graphic equalizer, autoadjustment of other settings in line with the equalizer, and a station scanner for music channels on the Web. If you're interested in typical corporate streaming media usage, you can probably skip RealPlayer Plus.

To obtain these products, simply download them from RealNetworks' Web site. After a 30-day evaluation period, you can contact RealNetworks to obtain license keys that turn the evaluation versions into legitimate products.

RealServer 6.1 offers new features for mixing advertising with streaming media, a canned system to simplify ISP hosting, and improvements in the use of multiple processors. Developers can now use TCP to connect to RealServer systems across firewalls. You can also automatically archive multirate files (which I describe later) as you create them.

At press time, RealNetworks had updated these products to version 7.0. The new versions add many user interface (UI) enhancements, primarily in the area of Internet music and video playback. Some of the valuable new features include the ability to stretch the window to any size and to open multiple instances. RealPlayer 7.0 integrates with America Online (AOL) Instant Messenger so that you can send links to clips to your friends.

Setup and Administration
The RealServer setup process asked me for the location of my key file (which paying customers receive). Your key, which might have an expiration date, is encoded with the number of simultaneous streams you paid for. I entered the key when the installation process prompted me to do so. I specified an administrator username and password; the remainder of the setup process was automatic.

The product's RealAdministrator program (or Monitor), which Screen 1 shows, is an HTML and JavaScript application that contains system configuration settings. RealAdministrator executes its settings through HTTP to the server. Most of RealAdministrator's settings mirror entries in the rmserver.cfg file, which is an Extensible Markup Language (XML)-formatted configuration for the server; therefore, you can manually edit the settings. RealAdministrator's screens explain the product's settings only briefly, and very little context-sensitive Help exists. I referred frequently to the online documentation—a tiresome procedure for looking up individual settings. In general, however, the RealAdministrator program has improved tremendously over the years.

RealServer supports several methods of multicasting, which RealNetworks categorizes as Back Channel multicasting and Scalable multicasting. You can use multicasting to make efficient use of bandwidth.

Content Creation and Display
RealProducer Plus, the encoding program, requires separate installation. RealNetworks also ships a RealProducer ActiveX control that you can use to embed encoding facilities into your programs and into Windows Scripting Host (WSH). The RealProducer installation requested the serial number (i.e., key) that the company sent me after I paid for the product.

The RealProducer Recording Wizard represents RealServer at its most user-friendly. The Wizard offers two modes: a wizard that walks you through a basic encoding session and a conventional Windows program that lets you change settings individually. Using the wizard, you can record from a file (e.g., .mpeg, .avi), record from a media device (e.g., PC Camera, a VCR), or create a live broadcast over the Internet. After you gain some experience with the software, you'll probably use the standard Windows UI elements to control your recording. The recording process not only digitally encodes video and audio data but also compresses it.

Recording from a file is probably the most common situation. To maximize recording quality, users capture uncompressed video, then compress and encode it from the file. After you choose the file, you can specify such parameters as title, author, copyright, description, and keywords. If you capture video from a device (e.g., a VCR), one-step compressing and encoding are more compute- and I/O-intensive operations.

If you're using RealProducer Plus, you can create a file that has multiple bit rates—RealNetworks calls this capability SureStream. Creating a file that has multiple bit rates is convenient because it means you have fewer files to produce and manage. However, files with multiple bit rates are large and aren't compatible with HTTP streaming. You must use RealNetworks' proprietary streaming protocols to stream the files. (Many users prefer HTTP because it has no firewall problems.) Alternatively, you can create a single-rate file. RealProducer's main screen offers options for 28K Modem, 56K Modem, Single ISDN, Dual ISDN, DSL/Cable Modem, and Corporate LAN. Don't use greater bandwidth just because you have it. Test your videos. The quality of a particular video might be indistinguishable whether you've encoded it for dual ISDN or corporate LAN.

If you're using the RealProducer Recording Wizard, it next asks you to choose the quality of the audio encoding. Depending on your choice—Voice Only, Voice with Background Music, Music, and Stereo Music—RealNetworks uses codecs with different bandwidth requirements. My test video contained one person speaking, so I chose Voice Only. You make a similar quality judgment for video—Sharpest Image, Smoothest Motion, Normal Motion, and Slide Show. The Sharpest Image and Smoothest Motion options select video codecs that are biased toward motion or still image, and Normal Motion seeks a balance between the two. You'll use Slide Show only for still images. After the wizard instructs you to select an output filename, RealProducer confirms your settings.

When you click Finish, you return to RealProducer's nonwizard view. The software loads all your wizard settings into the UI. You can modify those settings or start the encoding. As you encode, you'll see the video play in two windows, one from the input source and the other encoded, as Screen 2, page 112, shows.

You can choose to create a pop-up player, in which case the Web page simply links to the .rm (encoded media) file that RealProducer created and the browser opens the associated player—in this case, RealPlayer. Alternatively, you can choose to embed the audio or video in a Web page using an ActiveX control in Microsoft Internet Explorer (IE) or a Netscape plugin. Finally, you can publish the page to an email message, and RealNetworks will run your email client to send it. If you're publishing to a public Internet site, you can add your clip to Janus, a RealNetworks search engine for multimedia content.

If you choose to publish a Web page, you can post files to FTP, HTTP, and RealNetworks servers. You'll probably take advantage of this capability once or twice to post pages you've created.

When you're creating or publishing a Web page, you can choose the option to create a metafile—a .ram file that contains one or more references to media content. The Web page can then refer to the metafile instead of the content. This feature simplifies many aspects of management. For example, to update media content, you simply change the appropriate metafiles—you needn't change the HTML files. Microsoft offers a similar feature in Advanced Streaming Format (ASF) files (i.e., .asx files).

You might find that you need to encode numerous files or periodically re-encode the same files. For such situations, RealNetworks provides the RMBatch program, which lets you encode from the command line. You can use a batch language or WSH to automate much of the encoding process and run the batch job overnight.

RealSlideshow is an easy-to-use program that lets you drag .jpg files to a storyboard to produce a timed slide show that streams from the server. If you have the Plus version of RealSlideshow, you can set text captions below the images and create effects such as fades and wipes. You can also create hyperlinks for each image. RealSlideshow outputs a cool XML-based format called Synchronized Multimedia Integration Language (SMIL—pronounced smile). The output file—another type of metafile—gives you structural information about the presentation and links to the images and music. However, although RealSlideshow is easy to use, it doesn't offer the power that Microsoft's tools offer in this arena—particularly the ability to stream PowerPoint slides. RealNetworks promises improvements soon.

RealNetworks' client, RealPlayer, is filled with ads and links to partner software. Clearly, RealNetworks hopes to stream revenue as well as media with RealPlayer. Although RealPlayer performs sufficiently, the client is busy with features for viewing news and pop culture. Business users might find this media chaos distracting. However, by embedding the player in a Web page, you can create simple playback UIs.

Documentation
When you buy products from RealNetworks, you receive printed documentation, but the online Help is the products' primary documentation. Although useful, the online Help is not a comprehensive treatment, however. You can find more detailed .pdf files and links to white papers at http://www.realnetworks.com/ devzone/library/index.html.

Windows Media Services 4.1
In the past couple of years, Windows Media Services has matured significantly. Microsoft's product is well suited for a high-traffic intranet or Internet multimedia site. Many Internet sites, such as CNN, offer both Windows Media Services and RealNetworks content. Other sites, such as Warner Brothers, offer Windows Media Services exclusively.

Like RealNetworks, Microsoft offers other types of streaming media besides video and audio. You can create simple storyboard presentations of graphics and audio with simple effects. Microsoft has one essential capability that RealNetworks lacks: You can output PowerPoint presentations directly to Windows Media Services formats and stream the presentations. You can also use an NT service (included with the product) to broadcast streaming PowerPoint presentations directly to users.

Windows Media Services 4.1's pricing is much simpler than RealNetworks' pricing—Windows Media Services, including the encoding tools and the client, is free. Of course, the server requires NT Server, which isn't free, and Windows Media Services clients count against your NT client license.

You can download Windows Media Services from Microsoft's Web site. Alternatively, for $11.95, you can order the product (and its documentation) on a CD-ROM called the Windows Media Technologies Jumpstart CD. Microsoft builds Windows Media Services into all versions of Windows 2000 Server (Win2K Server).

Setup and Administration
To install Windows Media Services on NT Server, you run several programs from the JumpStart CD. Windows Media Services requires NT 4.0 Service Pack 5 (SP5). Supposedly, the software can run on SP4, but Microsoft doesn't support this configuration. To run the Web-based Windows Media Administrator program, you need IE 5.0. IE 4.0 might work, but Microsoft doesn't support it. Also, Microsoft supports administration from Win98, but not from Win95.

The Windows Media Administrator is a Web-based program that has a richer interface than RealServer's administration program, thanks to the heavy use of ActiveX controls. The controls, such as the options to perform multicast and unicast streaming, are easy to manipulate. However, the program lacks some of RealServer's fine control, such as the capability to edit MIME types on the server. This and other functions, though, are available in other NT administration programs (e.g., the Internet Service Manager—ISM).

Windows Media Services typically uses Microsoft Media Server (MMS) as its streaming protocol. (By comparison, RealServer uses Real Time Streaming Protocol—RTSP—for this purpose.) However, the software can also perform multicast and unicast streaming over HTTP, which is useful for server-to-server transfers or for streaming through firewalls that might block the MMS ports.

Although you might be able to run a Web server and Windows Media Services on the same server, you're probably better off running your Web server on a different machine for performance and simplicity reasons. Enabling the server for HTTP unicast takes over port 80, on which you might be running a Web server. HTTP unicast uses a TCP back channel for error correction. HTTP unicast transfers from Windows Media Services don't conflict with Microsoft Internet Information Server (IIS), but HTTP unicast transfers aren't really streaming.

The PowerPoint 2000 Presentation Broadcast feature uses an NT service to stream PowerPoint presentations and synchronize them with audio and video. Although I experienced some problems loading the service, this feature impressed me. However, the alternative—generating .asf files directly from PowerPoint—might be easier, all things considered.

Windows Media Services includes advanced server-based features that Microsoft targets at Internet media companies. One feature, the Windows Digital Rights Management (DRM) system, is essentially a copy-protection system for multimedia content. DRM uses a separate Microsoft SQL Server 7.0 server as a clearinghouse for information about authorized users (e.g., user IDs). The server wraps the music or other content in an encrypted container. Users connect to their Web server and provide identification (e.g., a credit card number) as a key. The DRM server returns a license key to Windows Media Player, which then plays the clip. Microsoft announced this system several months ago to great controversy.

For users who want to create automated catalogs or pay-per-view events, Microsoft also offers—separately and at added cost—the Windows Media Event Guide and Windows Media Pay-Per-View Solution. The Windows Media Event Guide is a system for building catalogs of multimedia content. Microsoft bases the Windows Media Pay-Per-View Solution on SQL Server 7.0 and Site Server 3.0 Commerce Edition.

Content Creation and Display
Microsoft's content tools are steadily improving, but they're not as easy to use and as straightforward as RealNetworks' tools. The primary encoding tool, Windows Media Encoder, which Screen 3, page 115, shows, contains a variety of templates for common quality levels (e.g., 56 Dial-up Modem Video, 512 Video). You can fine-tune the Media Encoder options more effectively than you can tune RealNetworks' encoding options, but Microsoft's tools for creating Web pages and guiding you to a finished product are not as integrated as RealNetworks' tools.

Windows Media Services adds to PowerPoint 97 and PowerPoint 2000 the ability to export a slide show as an .asf file, which Windows Media Services can then stream to the client, as Screen 4, page 115, shows. You can use this feature in many scenarios, such as displaying a presentation on an Internet-connected Windows system without running PowerPoint.

Windows Media Author is similar to RealNetworks' RealSlideshow—you can use Windows Media Author to create time-synched slide shows of graphics, captions, music, and effects. Unlike RealSlideshow, Windows Media Author saves slide shows in a proprietary binary format. Microsoft's tool is also trickier to use.

The ASF Indexer is a post-encoding tool you use to add descriptive information, such as a title and copyright statement, to the .asf file. You can add markers (i.e., bookmarks) in the stream and let a user move directly to a marked point. (RealNetworks integrates similar functionality into its RealProducer tool.) You can use the ASF Indexer to integrate primitive scripting into the .asf file or execute an external script. Windows Media Services lets you create intermediary files called .asx files, like RealServer's metafiles, that act as pointers to encoded multimedia content.

The VidToASF and WavToASF command-line tools can automate encoding of raw audio and video to .asf files, but these tools perform no compression and provide only primitive options. Compared to RealNetworks' tools, which offer more comprehensive options and an ActiveX control, Microsoft's tools are uncharacteristically passive.

Windows Media Player has the distinct advantage of already residing on most Windows systems and is a good general-purpose media player intended for nonstreaming content. With three simple buttons that let you open the Web browser to Radio, Music, and a Media Guide, the Windows Media Services client is simpler and easier to use than RealNetworks' player. The lack of billboard clutter is welcome. Windows Media Player plays nearly all the audio and video formats you'll encounter, from audio (AU) files and .mpg files to some QuickTime formats. Years ago, Windows Media Player could play older versions of RealNetworks content, but that capability is missing from the latest version.

Documentation
Microsoft's Windows Media Services documentation is more effective than RealNetworks' RealServer online documentation, mostly because Microsoft's is available on the Jumpstart CD-ROM and therefore doesn't require a Web connection. However, both companies seem to treat their documentation as an afterthought.

The Verdict
Windows Media Services is steadily improving, but it's still second-rate. Microsoft has a history of eventually getting its applications right, and the company has come closer with this version. Microsoft's content creation and deployment tools, a weakness in the past, have improved, although they still fall short of RealNetworks' tools.

If you use either product's basic features, you'll be streaming media without too much trouble. But if you want to do anything fancy, you'll find yourself experimenting a lot. As an example, CNN's video page (http://www.cnn.com/videoselect) lets you choose to receive video using either the Microsoft or the RealNetworks client. CNN then plays the video embedded within the Web page instead of opening a client window. Once you've gained some experience, embedding a video in such a manner is easy, especially if you use RealNetworks' tools.

If you simply compare the two technologies, you'll see that RealNetworks clearly has maintained a lead over Microsoft—albeit a smaller one than past versions of RealNetworks' products achieved. However, technical excellence is never the only criterion in a comparison. The fact remains that Windows Media Services and its associated tools are free. To stay alive, RealNetworks needs to produce not only a competitive product but also a better product. And you need to determine whether RealServer can suit your needs in a way that warrants the extra cost.