Introduction
-- E-4 --
2.4.
Type of Writing
Disc-At-Once
When only a single recording session (lead in/data/lead out) is to be recorded onto a disk,
it is called “Disc-At-Once”.
When using Disc-At-Once, no additional data can be recorded onto the disc, even if
there is available capacity.
The advantage of this method recording is that it enables creation of discs that can be
played back on almost any CD player or CD-ROM drive, because there are no links
inserted between the data tracks.
Track-At-Once
When many sessions are to be recorded onto a disc, it is called “Track-At-Once”. If there
is space available on the disc, additional data can be recorded onto it.
The advantages of this method include being able to record additional sessions onto a
disc, and using a CD-ROM of backup data. (Refer to “Multisession”.)
Session-At-Once
A "Session-at-Once" recording almost corresponds to a "Disc-at-Once recording", i.e. all
data ("Lead-in", data area and "Lead-out" are written in one go.
The only difference is that the CD is not "finished", i.e. after a "Session-at-Once"
recording you still have the possibility to write a further "Session" on the CD at a later
date.
Multi-session
The recording of lead-in/data/lead-out is referred to as one session. The Disc-At-Once
method is also referred to as “Single Session”, because the disc is only recorded once. A
disc that has had multiple additional session recorded onto it using the Track-At-Once
method is called “Multisession”.
Packet Write
The Packet Write recording method was developed. It differs from Track-At-Once or
Disc-At-Once in that data is recorded in small fixed sectors of 64k bytes, known as
packets.
The advantages of this method are elimination in overhead per session and the
elimination of buffer under run errors. This method, however, cannot be utilized for audio
data. A number of formats, such as UDF and CD-R FS, can be used when recording
using the Packet Write method.
