01_LAYOUT_GB 22-11-2000 09:21 Pagina 29

CDRWAPPENDIXIX

(CONT )

ENGLISH

•A track written “at once” has 150 blocks of overhead for run-in, run-out, pre-gap and linking. Packet write, on the other hand, is a method whereby several write events are allowed within a track, thus reducing the overhead.

These “packets” are bounded by 7 blocks for run-in (4), run-out

(2) and link (1).

WHAT’S THE DIFFERENCE BETWEEN A “MULTISESSION” DISC AND A “MULTITRACK” DISC?

•A “session” is a unity on a CD which is bounded by lead-in and lead-out. A session contains one or several (up to 99 per disc) tracks.

•There are two types of tracks. A Red Book audio track is usually written in disc at once mode along with several other tracks in one session.

These tracks have index numbers in the subchannel which differentiate one from the other and which allow selective playback.

•The other type of track is the incrementally written type described above.

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