By Lou Dolinar
Sixth in a series
Updated Feb. 14, 2006

So you have a hundred or so CDs and you're ready to enter the world of digital music.

Where do you start?

One of your biggest investments will be time. It takes a couple of days and a fast computer to rip 100 CDs to your hard drive, and by and large you don't want the computer to do anything else while the rip is in progress. Every 10 minutes or so, you have to shove another CD into the tray.

That's why, early on, you want to figure out which codec, or converted file format, and compression rate you're going to use - you don't want to have to re-rip those files. Here are your options:

WAV is the file format for uncompressed music and sound that originated in the Microsoft universe, though it is also supported by Apple. (AIFF is the corresponding format for Macs.) Assuming the transfer is handled without error, the musical content of a WAV file that you rip to your hard drive is identical to the music file on the CD where it originated. (One CD can hold about 650 megabytes of data, but music albums are rarely filled to capacity, and more typically hold around 500 megabytes of music.)

If you have the disk space, WAV sounds great and is a pretty good format. Most software players and music hardware will rip and play WAV files directly. There's no wacky aftermarket add-ons to download, and the sound should be as good as the original.

The objection to WAV is space (you're only going to fit about 40 albums on a 20-megabyte iPod) and tagging, which can limit your choice of hardware and software.

The original WAV standard didn't have a system for assigning artist name, album name and other track information to the individual song file, so everyone sorta does their own thing. Thus my carefully ripped WAV library in MusicMatch didn't quite make it into iTunes - only the track name and artist show up in the library listing. The same problem pertains to my new favorite player, the uber-geeky Foobar 2000 that runs under Windows. On the other hand, MusicMatch has no problems sharing a library with WinAmp and maintaining all data intact. Both programs can export WAV to MP3 format.

Tagging isn't an issue with compression codecs, which were designed for music.

There are two kinds of compression: lossy and lossless. Lossy codecs like MP3 were what created digital music, largely because a few years ago, small files were a must for storing and trading music on smallish hard drives and pokey modems.

Lossy codecs are based on so-called psychoacoustic analysis, which means that someone's spent a lot of time figuring out what parts of music most people don't hear. This stuff gets thrown out to varying degrees determined by the bit rate at which the music is encoded. The more that's thrown out, the smaller the file and the lower the quality. Some codecs are said to sound better than others at comparable bit rates, though that's often a personal call.

The various codecs allow for different bit rates - for MP3s and music, typically from 64 to 320 bits per second, and file sizes as small as a 20th the size of the original. In general, a doubling of bit rate, i.e. a doubling of file size, is audible as improved quality in mainstream portable players such as the iPod, or on reasonably good home systems. Some codecs incorporate schemes for "variable bit rate," where the compression algorithm can throttle bit rate up or down depending on the complexity of the music.

Lossless codecs, like FLAC, are exactly what they sound like - a purely mathematical translation removes redundancies in the files, just as we use zip programs to shrink text and program files, without throwing out any data. Lossless codecs average about a 50 percent reduction in file size, ranging from as little as 30 percent of the original file for quiet, well-behaved music (think Jack Johnson) as opposed to loud classical or hard rock, which can take up as much as 70 percent of its original format. Most players support at least one lossless codec.

So how much compression should you use? We'll take a look at that in the next column.

The bottom line, compressed:

For the amount of music most people own, the capacity of a hard drive is so great that it is practical to store music in its original form with WAV or lossless codecs.

Hard-drive-based portables, such as the iRiver h320, are pretty nearly as good with high-bit-rate lossy compression, and folks with modest libraries can use lossless codecs.

Cheap light portables such as the iPod shuffle, assuming you put a reasonable amount of music on them, require fairly heavy compression and will compromise quality.

Ready, set, rip those CDs into digital

[NASSAU AND SUFFOLK Edition]

Newsday - Long Island, N.Y.

Date: Apr 18, 2005

Start Page: A.24

Edition: Combined editions

Section: BUSINESS & TECHNOLOGY

Text Word Count: 804 Document Text