Pregap

The pregap on a Red Book audio CD is the part of the soundtrack (index number 00), of a title ( index number 01 ) is preceded by the so-called "Table of Contents". Normally pregap is 2 seconds and includes silence.

Unusual use of pregap

Hidden audio tracks

Computer data in pregap

A further application of pregap is it, computer data along with audio on a CD ( even a session ) accommodate ( "i- Trax "). In this case, can also be accessed with only single -session- capable CD -ROM drives on these data, an audio CD player, however, plays the CD like a normal audio CD.

This method is obsolete with the proliferation of multi-session -capable drives. In 1996, Microsoft caused by an update to Windows 95 in the driver SCSI1HLP.VXD that pregap track is no longer accessible. (In Windows XP, this behavior also. ) It is unclear whether this change was intentional in the behavior of Microsoft Windows from Microsoft: it is conceivable that Microsoft intended to dissuade developers from using this method and instead focus on the standardized " CD to put extra " format, which is described in the Blue Book standard.

On Windows, using software such as IsoBuster still access to the data part of such a CD possible.