Atrac (Adaptive Transform Acoustic Coding); Sound Skip Guard Memory; Utoc (User Table Of Contents) - JVC XM-EX90 Instruction Manual

ATRAC (Adaptive TRansform Acoustic Coding)

(dB)
+20
High
0
-20
Ear
sens.
-40
-60
Low
20 50
Low

Sound skip guard memory

During normal
playback

UTOC (User Table Of Contents)

52
XM-EX90
5k 10k
100 500 1k
Audio High
freq.
stop
During vibration
UTOC Contents
1st tune...
2nd tune...
Music data
3rd tune...
The MD (Mini Disc) has half the size of the CD but can
record data for the same period of time. This has been
made possible by the newly developed ATRAC (Adaptive
TRansform Acoustic Coding), which compresses data by
cutting the audio components that are inaudible to the
human sense of audition. This technology reduces the
recorded data to about 1/5 the original data quantity and
enables recording/playback of data for up to 74 minutes.
15k
(Hz)
The sound skip guard memory stores some data of the
played track so that the played audio does not skip due to
vibration during MD (Mini Disc) playback.
In case the optical laser cannot read disc signal due to
vibration, the actually reproduced audio is not interrupted
because the data stored in the guard memory is available.
The recordable MD (Mini Disc) contains the recording of
UTOC (User Table Of Contents) in addition to music data
itself. The UTOC includes the information on the positions
the tracks are recorded, markings between tracks and order
of tracks, so tracks can be searched quickly by referring to
it. The editing operations consist of altering the UTOC
contents and the actual music data does not need to be re-
recorded.