GMC 2012 Sierra Denali Owner's Manual page 201

For the Radio with USB and
Six-Disc CD (MP3):
1. Press the softkey positioned
under the RDM tab until
Randomize All Discs displays
to play tracks from all CDs
loaded in random order.
2. Press the softkey positioned
under the RDM tab until Random
Current Disc displays to play
tracks from a single CD in
random order.
3. Press the same softkey again to
turn off random play.
MP3 Supported Files
The Radio with CD (MP3), Radio
with USB and CD (MP3), and Radio
with USB and Six-Disc CD (MP3)
have the capability of playing an
MP3 CD-R or CD-RW disc.
Format
Radios that have the capability of
playing MP3s can play .mp3 or .wma
files that were recorded onto a
CD-R or CD-RW disc. The files can
be recorded with the following fixed
bit rates: 32 kbps, 40 kbps, 56 kbps,
64 kbps, 80 kbps, 96 kbps, 112 kbps,
128 kbps, 160 kbps, 192 kbps,
224 kbps, 256 kbps, and 320 kbps or
a variable bit rate.
Compressed Audio or Mixed Mode
Discs
The radio can play discs that
contain both uncompressed CD
audio and MP3 files. If both formats
are on the disc, the radio reads all
MP3 files first, then the
uncompressed CD audio files.
Infotainment System
CD R or CD RW Supported File
and Folder Structure
The radio supports:
Up to 50 folders.
Up to 8 folders in depth.
Up to 50 playlists.
Up to 255 files.
Playlists with an .m3u or .wpl
extension.
Files with an .mp3, .wma, or .cda
file extension.
Root Directory
The root directory is treated as a
folder. Files are stored in the root
directory when the disc or storage
device does not contain folders.
Files accessed from the root
directory of a CD display as
F1 ROOT.
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