Chapter 8. Playing, Serving, and Streaming MP3

Whether MP3 is in fact a revolution remains to be seen. But it is no less than a grassroots phenomenon that is changing the way people listen to music, the way musicians build audiences, and the way record companies and promoters do business. So what is so exciting about MP3? Simple: the MP3 format provides relatively good audio quality in small file sizes, which means that music can be transmitted more easily over the Internet, and people can build file-based music collections without overstuffing their hard drives. It also means that artists have a new way to reach audiences without having to rely on the recording industry.

The MP3 format allows the person doing the encoding to establish his or her own quality-to-file-size ratio, so files can be very small with low fidelity, or comparatively large with high fidelity, or anywhere in between. These ratios usually are established by adjusting the sampling frequency and the number of bits per second (the bitrate) devoted to storing audio data. The de facto standard is considered 128 kilobits per second (Kbps), 44.1 kilohertz (kHz). At this quality level, a four-minute MP3 file weighs in at roughly 3.5 MB and sounds nearly as good as a compact disc. The same track in uncompressed WAV or AIFF format would be a whopping 40 MB. MP3 encoding can reduce the size of uncompressed audio by a factor of 10 or more while still retaining audio fidelity that approaches CD quality.

8.1. MP3 pros and cons

Naturally, there are both pros and cons to the MP3 format. Although it has garnered a huge following, the format does have disadvantages that should be considered by anyone preparing to test the waters of MP3 audio.

8.1.1. Advantages

Relatively high fidelity
Easy, inexpensive (generally free) encoding
Simple distribution, via HTTP and FTP protocols, and via CD or other portable storage media
Streaming implementation via server additions
Availability of sample source code, which creates potential for lots of competition, players, and encoders for all platforms

8.1.2. Disadvantages

Relatively large downloads for analog modem users
Decoding device (MP3 player) required (though Windows and BeOS come with native MP3 codecs and players, and most Mac users have QuickTime, which can also handle MP3)
Few security options available (although changes in this area are expected)
Some downloaded files are of poor quality; poorly encoded files often exhibit a slight "hollowness" or "swishiness" and may contain skips or glitches


7.8. Summary		8.2. What is MP3?

Chapter 8. Playing, Serving, and Streaming MP3

Contents:

8.1. MP3 pros and cons

8.1.1. Advantages

8.1.2. Disadvantages