LaCie Portable DVD±RW •
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Helpful Technical Information
User Manual
page 18
4.2. DVD±RW Writing Methods
Disc at Once (DAO) –
A DVD writing process in which the entire
DVD is recorded in one session, and data cannot be added after the
recording is finished. Differs from the CD-R DAO method because
the lead-in, data area and lead-out areas are all written sequen-
tially.
Session at Once (SAO) –
A writing process which is similar to DAO,
where all of the information is written in one session, but SAO allows
for the ability to begin another session and record at a later time.
This mode allows for greater control of the recording process than
Packet Writing (PW)
or
TAO
, and more disc space can be utilized
because there is no need for gaps between tracks.
Incremental Recording (IR) –
A writing process that is similar to the
Session at Once (SAO) CDR writing method; files may be added
directly to the DVD-R disc one recording at a time, instead of record-
ing the files to a hard drive before writing the disc. The minimum
recorded size, though, must be at least 32KB (even if the file to be
recorded is smaller than that), and capacities and write speeds are
decreased due to the overhead of combined lead-in/out areas and
data. Also, the disc must be finalized before it may be played back
by a drive other than the drive recording the disc.
Multi-Border Recording (MBR) –
A writing process that is very similar
to IR, MBR allows you to make an IR disc and then play the disc
back on a device that recognizes this type of recording method. MBR
creates a very short boundary zone around a recording session so a
compatible player or DVD-ROM drive does not attempt to play be-
yond the border of the recorded area, instead allowing the unfinal-
ized disc to be read by a player that supports this recording method.
Restricted Overwriting (RO) –
With this method, if a disc has already
been written to, new data segments can be randomly inserted any-
where within the recorded boundary. New data, however, can only
be added to an area of the disc that has already been recorded over
and from the point where the last session was stopped.
Packet Writing (PW) –
A drag-and-drop writing process writing pro-
cess that is very useful for data backup. Buffer underrun* is impos-
sible in this mode, because the data is written in “packets” of a few
KBs. Packet Writing is a CPU-intensive process because it constantly
checks the available space on the disc.
* Buffer Underrun – The recording of a disc is a system-intensive ap-
plication, and the rewritable drive needs a constant stream of data.
A buffer underrun occurs when the stream of data to the rewritable
drive is not fast enough to keep the rewritable drive’s buffer full,
causing the an error in the recording process. If this problem occurs
often, turn down the recording speed.
Table 02 - DVD±RW Writing Methods
DAO
SAO
IR
MBR
RO
PW
CD
✔
✔
✔
DVD
✔
✔
✔
✔
