MP3: Ripping and Encoding

Of all the ways to get an MP3 file onto your Web site, undoubtedly the most common is to rip it off of a CD, encode it as an MP3, and upload it to your site. The Creative element among us will often skip the first step---preferring to upload our own work.

Let's look at both procedures:

Ripping

Ripping from a CD is pretty straightforward. A quick visit to download.com or the use of any search engine will help find all the rippers you'll ever need, and then some, but I usually stick to a couple of standbys. To get started, download either of the popular and well-documented applications: Real Networks RealJukebox or MusicMatch Jukebox. With either application, to rip a CD, you just put it in the drive, launch the application, select the tracks you want to rip and where you want to save them. A few minutes later you have an MP3, Real or WAV copy of the music on your hard drive. The Real application, by the way, also puts a lot of emphasis on linking you to the companies that produce the CDs, displaying album cover art, artist info, and of course, where and how to buy more. It is a functional, stable and popular application.

A new application worth mentioning if for no other reason than that it comes from top-dog audio software mongers, Sonic Foundry, is Siren Jukebox. Siren not only rips and converts, but burns audio to CD. Like the other jukeboxes, it lets you make playlists and supports MP3, WAV, and WinMedia. Siren also has reverb, tempo change, and EQ functions and can upload songs to a portable MP3 player.

One of the few gotchas in this process is getting stuck with one of the rippers that extract CD tracks, not through direct digital copying, but via your sound card. These rippers convert the CD audio to analog, then digitize it again with the sound card. Not only do these repeated A/D conversions degrade audio quality in the best of circumstances, but most sound cards don't do a particularly good job converting anyway. The analog process also takes a lot longer than digital ripping. Use a ripper that extracts digitally for better-sounding audio and less wasted time. Another potential pitfall is that some older CD-ROM drives themselves don't support digital (CDA) extraction.

Encoding

Encoding is the second half of the ripping process, and happens automatically when you rip. Real, MusicMatch and Siren jukeboxes all let you choose the format in which you want to save ripped files-all three encode MP3 and WAV, but Real and MuiscMatch don't do Windows Media and Siren doesn't do Real.

Both applications also convert files already on your hard disk. When RealJukebox converts and encodes, it gives you options of four data rates for Real and MP3, and has a Variable Bit Rate (VBR) checkbox for MP3s. MusicMatch Jukebox focuses somewhat less on providing record company information, though it does give you the basics, and it also offers somewhat more functionality. It gives you a number of programmable parameters that let you maximize audio quality and bandwidth for each particular situation (Figure 1). That is, you can set the degree of compression and consequent data rate at which audio will play. And you can choose whether to encode with variable or constant bit rates (CBR). A variable rate will get you the highest quality (at the expense of a predictable file size), and a constant rate will keep file size down, but is less efficient at encoding.

Fig 1. MusicMatch Jukebox gives you plenty of options for customizing the ways your files stream.

Having these settings at your disposal is great if you want to customize for quality or streaming purposes. You can, for example, set up different bit-rate versions of your files at so they can be streamed at the best quality possible for the bandwidth of your audience. The only problem with this is the problem that always comes with choices: more trial and error, more time spent and more decisions to make. Freedom is a terrible responsibility.

MusicMatch also has the added flexibility of letting you rip not just whole tracks, but whatever portion of a track you may want.

Streaming Playlists

If you want to stream a series of files with a single click, you'll need to create a metafile. This is either a .ram file (for Real Audio) or an .m3u file (for MP3s).

To stream a series of files in succession, first create and upload your .ram or .mp3 audio files. Next, create an ordinary text file and save it with the extension: ".ram" or ".m3u", depending on the media involved. In this file, list the URL for each clip you want to play. Then upload the .ram or .m3u file to your site. Link to this file on your Web page, and when a visitor to your site clicks on the .ram or .m3u file's URL, the server sends that file to the browser, which hands it to the person's media player. The player uses the URLs in the .ram / .m3u file to play the clips from the server in the order in which you listed them.