Formats


In the context of this book, a format is the technology used to encode and stream audio over the Internet. The four major formats include MP3, Windows Media, RealMedia, and QuickTime, although other lesser known formats also exist. Anyone with suitable audio know-how, programming skill, and time can create a streaming audio format, and many have.

NOTE

A list of lesser-known formats such as Ogg Vorbis, Beatnik, Clipstream, and more is included in Chapter 12, " Advanced Authoring Techniques."


Why Different Formats Are Available

The reason that multiple formats exist is equal parts corporate struggle for dominance and the creativity and curiosity of software programmers (different people trying to solve the same problem in different ways). Although several streaming audio formats exist, this book focuses on the most commonly used formats: RealNetworks' RealMedia, Microsoft's Windows Media, Apple's QuickTime, and SHOUTcast's MP3 offering. A brief overview is given for the less common, but worthy open-source standard format Ogg Vorbis.

NOTE

Each format contains one or more codecs, a specific software tool used to compress and decode any kind of media, including audio. Some codecs overlap between formats. For example, all formats that are covered in this book support the MP3 codec. It can be confusing, but MP3 is technically only a codec, not a format.


How Do Formats Differ, and How Are They Similar?

Although all formats provide the same basic functionality, each has its pros and cons. All the formats support the MP3 codec, but some also have their own higher-quality, proprietary codec. All formats can be integrated with other technologies, such as Flash, DHTML, and JavaScript, as well as embedded into more elaborate presentations. Each format works better with some technologies than with others, so it is best to research each independently with your individual presentation requirements in mind.

RealNetworks' RealMedia streaming audio format has been around the longest, and streaming media is the company's backbone. Long experience and a fairly reliable product line on a variety of operating system platforms are offset by a high price tag relative to other formats. This is especially true if you run your own server. You will need to pay a license fee based on your maximum projected concurrent (simultaneous) user load. RealNetworks does provide free entry-level versions of their tools and servers to get you hooked. The RealMedia format includes its own optimized audio codec (just like Windows Media and QuickTime) that offers the same quality audio as MP3 in a smaller file.

Microsoft's Windows Media got a late start in the streaming audio game. However, because statisticians report that 90% of all computers use the Windows operating system (and Windows Media components are included on all new Windows-based PCs), it's been a cakewalk for Microsoft to quickly develop a huge number of Windows Media-enabled users. That makes it an easy sell for content providers to use the Windows Media format. Because Windows Media is a small part of a large company, crucial survival profitability from their streaming media tools isn't necessary. On the upside, Microsoft doesn't charge for the software. On the downside, because the server product is used to drive sales of the Windows OS, it's only available for Windows NT/2000. A Macintosh-compatible player is available, as well as limited support for Macintosh users wishing to author in the Windows Media format. The Windows Media format also includes a proprietary audio codec that, like RealNetworks and QuickTime, provides more efficient compression than MP3. (That is, it offers the same quality in less space, or better quality in the same space.)

QuickTime, Apple's proprietary digital media management technology, has been around longer than RealAudio; however, only in recent years has a full, streaming audio component been added. Partially because of Apple's history as primarily a desktop and content-creation platform (as opposed to being a server solution), it's been harder for Apple to get support from within the streaming industry. Strong historical ties to the creative community have helped compensate for this, along with a reinvigorated product line. Like Windows Media, QuickTime doesn't charge per-user server license fees. Entry-level encoding tools cost around $30. QuickTime's audio codec of choice is licensed from Canadian industry partner QDesign, which, yet again, provides better quality compression than MP3, with the same audio quality in less space, or better quality in the same space.

MP3 (MPEG 1, Layer III) is actually an open standard codec and not specifically a streaming audio format. MP3's wild popularity has resulted in it being included in many different Internet audio-delivery products, both for download and, in recent years, streaming. For the purposes of this book, Nullsoft's Winamp and SHOUTcast system will be used for MP3 streaming format examples. Licensing for the MP3 codec is controlled by Fraunhofer-Gesellschaft. Information on how to write your own encoder or player using the MP3 codec is available for a modest price, but including it in your software requires a licensing agreement with the Fraunhofer folks. The thoughtful crew at Nullsoft has taken care of all of the licensing issues and offers its software for free. Thus, no additional licensing fees are involved for each concurrent streaming user.

See Chapter 2, "Preparing Yourself," to decide which format works best for your individual needs.

Standards: Proprietary Versus Public

It's important to be aware of certain basic differences between streaming audio formats and their family of tools, products, and software. Some products are built on open systems and standards, such as MP3, allowing for any software author to add features and usefulness, in which case, all users benefit. Other products are built around proprietary formats, such as Windows Media, RealMedia, and QuickTime, and are designed to maintain the intellectual property value of the company, ensuring profit and longevity. Obviously, in times of market growth, there's considerable corporate investment toward proprietary system innovation. Conversely, during times of cutbacks, corporate proprietary advances tend to stop. But progress is always being made in the open-standard community. Everyone benefits because nobody has to toe a corporate bottom-line. Interestingly, the more popular that open-standards are, the more the corporate community participates in them. That means less control by a single corporation over streaming audio distribution channels. Who wants to suddenly find they can't afford to stream their music because the one company that provides the service has decided to double its price? It's an old story.

NOTE

Whenever possible, supporting open standards is encouraged. The use of open standards actively helps the industry as a whole by supporting common sense, real-world development of useful tools.




Streaming Audio. The FezGuys' Guide
Streaming Audio: The FezGuys Guide
ISBN: B000H2N1T8
EAN: N/A
Year: 2001
Pages: 119

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net