compression ratio TOYOTA xB 2008 Accessories, Audio & Navigation (in English)

31
MP3, WMA and A AC
files
• MP3 is short for MPEG Audio Layer 3 and
refers to an audio compression technology
standard.
• WMA is short for Windows Media
TMAudio
and refers to an audio compression tech-
nology that is developed by Microsoft
Corporation. WMA data can be encoded
by using Windows Media Player version 7
or later.
• AAC is short for Advanced Audio Coding
and refers to an audio compression tech-
nology standard.
• With some applications used to encode
WMA files, this unit may not operate cor-
rectly.
• With some applications used to encode
WMA files, album names and other text
information may not be correctly dis-
played.
• This unit allows playback of MP3/ WMA /A AC
files on CD-ROM, CD-R and CD-RW discs.
Disc recordings compatible with level 1
and level 2 of ISO9660 and with the
Romeo and Joliet file system can be
played back.
• MP3/WMA/AAC files are not compatible
with packet write data transfer.
• The maximum number of characters which
can be displayed for a file name, including
the extension (.mp3, .wma, .m4a), is 64 ,
from the first character.
• The maximum number of characters whichcan be displayed for a folder name is 64 .
• In case of files recorded according to the
Romeo file system, only the first 64 char-
acters can be displayed.
• The folder selection sequence for playback
and other operations becomes the writing
sequence used by the writing software.
For this reason, the expected sequence at
the time of playback may not coincide with
the actual playback sequence. However,
there also is some writing software which
permits setting of the playback order.
MP3 additional infor-
mation
• Files are compatible with the ID3 Tag Ver.
1.0, 1.1, 2.2, 2.3 and 2.4 formats for dis-
play of album (disc title), track (track title),
artist (track artist) and comments. Ver. 2.x
of ID3 Tag is given priority when both Ver.
1.x and Ver. 2.x exist.
• The emphasis function is valid only when
MP3 files of 32, 44.1 and 48 kHz frequen-
cies are played back. (16, 22.05, 24, 32,
44.1, 48 kHz sampling frequencies can be
played back.)
• There is no m3u play list compatibility.
• There is no compatibility with the MP3i
(MP3 interactive) or mp3 PRO formats.
• The sound quality of MP3 files generally
becomes better with an increased bit
rates. This unit can play recordings with bit
rates from 32 kbps to 320 kbps, but in
order to be able to enjoy sound of a certain
quality, we recommend using only discs
recorded with a bit rate of at least 128
kbps.
IMPORTANT
•When naming an MP3/
WMA/AAC file, add the cor-
responding filename exten-
sion (.mp3, .wma, .m4a).
•This unit plays back files
with the filename extension
(.mp3, .wma, .m4a) as an
MP3/ WMA /AAC file. To pre-
vent noise and malfunc-
tions, do not use these
extensions for files other than
MP3/WMA/AAC files.

34
Terms
Packet writeThis is a general term for a method
of writing on CD-R, etc. at the time
required for a file, just as is done
with files on floppy or hard discs.
Bit rateThis expresses data volume per sec-
ond, or bps units (bits per second).
The higher the rate, the more infor-
mation is available to reproduce the
sound. Using the same encoding
method (such as MP3), the higher
the rate, the better the sound.
Multi-sessionMulti-session is a recording method
that allows additional data to be
recorded later. When recording data
on a CD-ROM, CD-R or CD-RW, etc.,
all data from beginning to end is
treated as a single unit or session.
Multi-session is a method of record-
ing more than 2 sessions in one disc.
CD-DACD-DA is an abbreviation of Compact
Disc Digital Audio. It refers to the
uncompressed format of regular
CDs.
ID3 TagThis is a method of embedding track-
related information in a MP3 file. This
embedded information can include
the track title, the artist’s name, the
album title, the music genre, the year
of production, comments and other
data. The contents can be freely edit-
ed using software with ID3 Tag edit-
ing functions. Although the tags are
restricted to the number of charac-
ters, the information can be viewed
when the track is played back.
ISO9660 formatThis is the international standard for
the format logic of CD-ROM folders
and files. For the ISO9660 format,
there are regulations for the follow-
ing two levels.
Level 1:
The file name is in 8.3 format (the name
consists of up to 8 characters, half-byte
English capital letters and half-byte
numerals and the “_” sign, with a file-
extension of three characters.)
Level 2:
The file name can have up to 31 charac-
ters (including the separation mark “.”
and a file extension). Each folder contains
less than 8 hierarchies.
Extended formats
Joliet:
File names can have up to 64 characters.
Romeo:
File names can have up to 128 characters.
m3uPlaylists created using the
“WINAMP” software have a playlist
file extension (.m3u).
MP3MP3 is short for MPEG1 & 2 Audio
Layer3. It is an audio compression stan-
dard set by a working group (MPEG) of
the ISO (International Standards
Organization). MP3 is able to compress
audio data to about 1/10 the level of a
conventional disc.
WMAWMA is short for Windows MediaTM
Audio and refers to an audio com-
pression technology that is developed
by Microsoft Corporation. WMA data
can be encoded by using Windows
Media Player version 7 or later.
Microsoft, Windows Media, and the
Windows logo are trademarks, or
registered trademarks of Microsoft
Corporation in the United States and/
or other countries.
AACAAC is short for Advanced Audio
Coding and refers to an audio com-
pression technology standard used
with MPEG2 and MPEG4.