Alpine CDA-9855R - Manual (Page 17)

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What is WMA?
WMA, or “Windows Media™ Audio,” is compressed audio data.
WMA allows you to create music files and store them at higher
ratios of compression than MP3 audio data (approx. half
original size). This is achieved while still maintaining CD
quality sound.
Method for creating MP3/WMA files
Audio data is compressed by using MP3/WMA specified
software. For details on creating MP3/WMA files, refer to the
user's manual for that software.
MP3/WMA files that can be played back by this device have the
file extension “mp3” / “wma”. Files with no extension cannot be
played back. (WMA ver. 7.1, 8 and 9 are supported)
Supported playback sampling rates and bit rates
MP3
Sampling rates : 48 kHz, 44.1 kHz, 32 kHz, 24 kHz, 22.05
kHz,16 kHz, 12 kHz, 11.025 kHz, 8 kHz
Bit rates: 8 - 320 kbps
WMA
Sampling rates : 48 kHz, 44.1 kHz, 32 kHz
Bit rates:
48 - 192 kbps
Note that for sampling rates, this device’s frame display (Page
13) may not display correctly.
This device may not play back correctly depending on
sampling rates.
ID3 tags/WMA tags
This device supports ID3 tag v1 and v2, and WMA tag.
If tag data is in an MP3/WMA file, this device can display the
title (track title), artist name, and album name ID3 tag/WMA
tag data.
This device can only display single-byte alphanumeric
characters (up to 30 for ID3 tags and up to 15 for WMA tags)
and the underscore. For non-supported characters, “NO
SUPPORT” is displayed.
The tag information may not be correctly displayed,
depending on the contents.
Producing MP3/WMA discs
MP3/WMA files are prepared, then written to a CD-R or CD-
RW using CD-R writing software. A disc can hold up to 510
files/folders (including Root Folders). However, the maximum
number of folders is 255.
Media supported
The media that this device can play back are CD-ROMs, CD-
Rs, and CD-RWs.
Corresponding File Systems
This device supports discs formatted with ISO9660 Level 1 or
Level 2.
Under the ISO9660 standard, there are some restrictions to
remember.
The maximum nested folder depth is 8 (including the root
directory). The number of characters for a folder/file name is
limited.
Valid characters for folder/file names are letters A-Z (all
caps), numbers 0-9, and ‘_’ (underscore).
This device also can play back discs in Joliet, Romeo, etc.,
and other standards that conform to ISO9660. However,
sometimes the file names, folder names, etc., are not
displayed correctly.
Formats supported
This device supports CD-ROM XA, Mixed Mode CD,
Enhanced CD (CD-Extra) and Multi-Session.
This device cannot correctly play back discs recorded with
Track At Once or packet writing.
Order of files
The unit plays the files in the order that the writing software
writes them. Therefore, the playing order may not be the same
as the order you input. The playback order of the folders and
files is as follows. However, the folder and file playback order
differs from the folder no. and file no. indicated on the display.
Terminology
Bit rate
This is the “sound” compression rate specified for encoding. The
higher the bit rate, the higher the sound quality, but also the larger
the files.
Sampling rate
This value shows how many times per second the data is sampled
(recorded). For example, music CDs use a sampling rate of 44.1
kHz, so the sound is sampled (recorded) 44,100 times per second.
The higher the sampling rate, the higher the sound quality, but also
the larger the volume of data.
Encoding
Converting music CDs, WAVE (AIFF) files, and other sound files
into the specified audio compression format.
Tag
Song information such as track titles, artist names, album names,
etc., written into MP3/WMA files.
MP3: ID3 tag
WMA: WMA tag
Root folder
The root folder is found at the top of the file system. The root folder
contains all folders and files.
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Folder MP3/WMA File
Root Folder