[linux-audio-user] Mystery first "track" on many CDs?

[Clemens Ladisch]

Paul Winkler wrote:
> I've noticed that a number of CDs contain an apparently spurious
> first track that's apparently very short (about a tenth of a
> second) and contains no audible signal.  What the heck is the
> point of this track?

None.

Most positions on an audio CD are specified as sector numbers.  The
Red Book says that the start of the first track is at sector 0; the
table of contents is placed in the lead-in area in sectors -32 to -1.

Some CDs (and/or some CD drives) get something wrong so that the first
track is reported to start at sector 32.

One sector is 1/75th of a second (588 frames), so usually nobody
notices this.

> File : track00.cdda.wav

Data before the first track is grabbed as "track 0" which doesn't
ordinarily exist on audio CDs.

> Frames      : 5880

This is 10 sectors, not 32, so the explanation above doesn't apply.
;-)


HTH
Clemens