Audio CD (CD-DA) Tracks and Indexes

<< Audio CD (Compact Disc Digital Audio or CD-DA) Format

<< Herong's Tutorial Notes on CD/DVD

This section describes the logical format of tracks and indexes of an audio CD (Compact Disc Digital Audio or CD-DA).

From a logical point of view, an audio CD (Compact Disc Digital Audio or CD-DA) is divided into tracks. One track represents one continuous segment of music data that the audio player should play as a single piece.

An audio CD can have upto 99 tracks.

A track can have upto 100 indexes. Index starts with 0. But, audio CD players usually starts to play music from index 1.

To find out how many tracks on an audio CD, you can insert it into a Windows system and test it in command window:

C:\>d:

D:\>dir
 Volume in drive D is Audio CD
 Volume Serial Number is 0247-8212

 Directory of D:\

12/31/1994  08:00 PM                44 Track01.cda
12/31/1994  08:04 PM                44 Track02.cda
12/31/1994  08:07 PM                44 Track03.cda
12/31/1994  08:10 PM                44 Track04.cda
12/31/1994  08:12 PM                44 Track05.cda
12/31/1994  08:16 PM                44 Track06.cda
12/31/1994  08:21 PM                44 Track07.cda
12/31/1994  08:26 PM                44 Track08.cda
12/31/1994  08:31 PM                44 Track09.cda
12/31/1994  08:35 PM                44 Track10.cda
12/31/1994  08:39 PM                44 Track11.cda
12/31/1994  08:43 PM                44 Track12.cda
12/31/1994  08:47 PM                44 Track13.cda
12/31/1994  08:51 PM                44 Track14.cda
12/31/1994  08:55 PM                44 Track15.cda
12/31/1994  08:58 PM                44 Track16.cda
12/31/1994  08:02 PM                44 Track17.cda
12/31/1994  08:05 PM                44 Track18.cda
              18 File(s)            792 bytes
               0 Dir(s)               0 bytes free

In the test output record above, my CD drive is assigned with drive letter D. The output shows that my audio CD has 18 tracks (18 songs).

The next question is to find out where the TOC (Table Of Contents) is recorded on the audio CD. the TOC contains the list of sound tracks on the CD, and list of indexes for each track.

The first index (index 0) on each track is also called pregap, which is about 2 seconds of silence on normal audio CDs. But some audio CDs could record an extra song at index 0, which is called "hidden tracks".

Sections in This Chapter

Audio CD (CD-DA) Physical Parameters

Audio CD (CD-DA) Data Structure

Audio CD (CD-DA) Tracks and Indexes