Very little, in fact. The relevant fact is this: digital audio files are large. Much larger than text or even graphics, and video files are bigger yet. One minute of CD-quality audio (44.1 kHz, 16-bit stereo) consumes about 10 megs. Of course, reducing the audio quality can yield smaller file sizes, but even the lowest quality level that would be acceptable for music (11.02 kHz, 8-bit mono) still produces files that take forever to download over a slow dial-up connection. Back in the days when folks connected to the Web over 9600-baud modems, it was apparent to all us audio weenies that audio over the Web was simply not practical, and full-motion video was about as imminent as interstellar travel. Or was it?
Humans being the clever souls that they are (especially when there's money to be made), someone came up with the idea of streaming media delivery. The concept behind streaming media is simple: the file can begin to play back before it is fully downloaded. Once the download begins, the system buffers the file so that it can be sent to the playback mechanism (soundcard) directly, without being written to the hard drive. RealAudio was one of the first, and has become the dominant software in this field, but there have been various others, one of which (StreamWorks) is still around. Naturally, Microsoft eventually got into the act, and now the Windows Media Player has streaming capabilities.
Minimizing download times for Web multimedia is far from the only application for streaming. It can also be used to broadcast live over the Web, destroying the geographic boundaries that used to restrict radio stations. It also provides a vehicle for distribution of audio or video over any kind of network, including LANs and WANs.
Even with streaming, performance over a dial-up connection is pretty tame. Early versions of RealAudio were limited to a very low-quality, compressed format that the company coyly compared to the fidelity of AM radio. Even this requires at least a 28.8k modem to work well. And, the Web being what it is, the buffer will overflow fairly often, causing dropouts, glitches and crashes. At one point in the early days, I noted that Web multimedia was waiting for the White Knight of increased bandwidth to show up.
Nowadays, the White Knight is at least loitering around the horizon, with cable modems, ADSL and other decent-bandwidth solutions becoming more widely available. Streaming applications have kept pace. The new Real Player offers a choice of several quality levels, corresponding to the bandwidth level of the user. In other words, the site owner can offer a lower-quality version suitable for dial-up users, and a high-bandwidth version for us lucky ducks with cable (or for internal use over a LAN). And don't look now, but the high-bandwidth format sounds pretty darn good, even approaching CD quality.
Streaming audio and video are heating up like an iron skillet, but the really white-hot news is SMIL. Synchronized Multimedia Integration Language is a new markup language, based on XML, that lets developers combine multimedia elements such as streaming media, text, graphics or whatever, in just about any way imaginable. For delivery over the Web, TV, a wireless palm pilot, tie pin or whatever. Think about it.
Internet.com covers streaming media and the whole Web multimedia revolution like white covers rice. Here are a few recent articles of interest, as well as a couple of comprehensive Web resources.
Streaming Media World
Guides, news, and everything about streaming media.
Real Progress in RealPlayer 7 (Streaming Media World)
Bottom line: RealNetworks is all about changing the way we Web.
RealPlayer 7 is their next step in that march. Find out how and why as
Tim Kennedy explores the major advances from the people who practically
own the stream in streaming media.
Web Audio Workshop
Sound and music on the Internet. How to create MP3, MIDI, RealAudio and other Web audio formats.
Internet Radio List
A directory of Internet radio stations, as well as tutorials and guides to the whole Internet radio scene.
Streaming (Internet Radio List)
This week we take a detour from our tried and true formula of reviewing
stations to put together some tips on how to get the most out of streaming
stations and the tools you'll need to get all areas covered.
A Streaming Media JukeBox - Part III:
Browser-Independent Version (Doc JavaScript)
Let your users rock your site with this cross-browser streaming media
player. By Dr. Yehuda Shiran.
The Tapeless Studio
The Magazine of Computer Audio. Sound card reviews, tutorials on creating MP3 files, audio software, the real audio player, audio compression, noise reduction, converting LPs to CD, and everything to do with computer audio and virtual recording studios.
