CDA Music Tracks File Format

CDA files are generally RIFF resources. The RIFF id of .CDA file is "CDDA" (43h, 44h, 44h, 41h). They contain only one data block called "fmt " (66h, 6dh, 74h, 20h). In current version of .CDA file, this block is 24 bytes long. Here's structure of it:

Offset	Length	Description
00h	02h	CDA file version. Currently equals 1. If it has other value, following data may be out of date.
02h	02h	Number of track.
04h	04h	CD disc serial number (the one stored in CDPLAYER.INI)
08h	04h	Beginning of the track in HSG format.
0Ch	04h	Length of the track in HSG format.
10h	04h	Beginning of the track in Red-Book format.
14h	04h	Length of the track in Red-Book format.

As you see, time is represented in two formats: HSG and Red-Book. HSG can be calculated as following:

time = minute * 4500 + second * 75 + frame

Red-book is much easier to use, because it contains minutes, seconds and frames in unmodified form, byte-packed:

Offset	Length	Description
00h	01h	Frame
01h	01h	Second
02h	01h	Minute
03h	01h	not used

Now, I'll show you an example file. First part is a hex dump of the file, the second is the explanation of the fields.

52 49 46 46 24 00 00 00  43 44 44 41 66 6D 74 20  RIFF$...CDDAfmt 
18 00 00 00 01 00 04 00  B8 24 F6 00 F7 11 01 00  .........$......
B4 5C 00 00 0A 25 0F 00  20 10 05 00              .\...%.. ...

01 00       - first version of CDA file :)
04 00       - fourth track
B8 24 F6 00 - serial number of CD in CDPLAYER.INI [F623B8]

F7 11 01 00 - begining of track in HSG format
B4 5C 00 00 - length of track in HSG format

0A 25 0F 00 - begining of track in Red-Book format (15:37)
20 10 05 00 - length of track in Red-book format (05:16)