virtual void SetPregapStart(int32_t blocks) = 0;

Sets the track pre-gap, in blocks, relative to the session start. 

The default pre-gap start is 0, which means there will not be any pre-gap written. 

The first track always has a pre-gap and it is 2 sec. (150 blocks) longer than the one specified in ICDTrack ( GetStart() - GetPregapStart() ). These 150 blocks are written as zeros at the very beginning of the user area and precede the custom pre-gap specified in ICDTrack. The Audio CD standard mandates that the first track must have a pre-gap of 2-3 sec. 

While PrimoBurner guarantees the minimum pre-gap of 2 sec. at the beginning of the session it does not restrict it to the maximum of 3 sec. This way it is possible to place an arbitrary audio content in the pre-gap of the first track. Such layout creates an Audio CD with the so called "hidden track" because normally the only way to play it is by manual rewinding before the start of track #1. Warning: Specifying the first track pre-gap to be longer than 3 sec. (GetStart() - GetPregapStart() > 75) violates the Audio CD standard. Some computer drives are known to have problems recognizing such Audio CDs. 

The pre-gap start cannot be greater than the length of the track. 

For maximum flexibility there is no validation of the track start, track end, pre-gap start, post-gap end, and index markers in this method. The application is responsible for setting the track and the session parameters correctly. 

IAudioCD begins writing only when the following condition is validated: pregap start <= start <= end <= postgap end. 

IDataDisc: to create a track with zero length set the track start and track pregap to 0 and the track end and track postgap to -1. 

GetLength

ICDTrack Class