GMC 2010 Sierra 1500 Crew Cab Owner's Manual page 340

The radio can play .mp3 or .wma files that were
recorded onto a CD-R or CD-RW disc.
The USB port can play .mp3 and .wma files that are
stored on a USB storage device as well as AAC files
that are stored on an iPod
The radio plays discs that contain both uncompressed
CD audio and MP3/WMA files depending on which slot
the disc is loaded into.
The DVD Player only reads uncompressed audio and
ignores MP3/WMA files on a mixed mode disc.
The CD Player reads both uncompressed audio and
MP3/WMA files on a mixed mode disc. Uncompressd
audio is played before MP3/WMA files. Press the CAT
(category) button to toggle between uncompressed
audio and MP3/WMA files.
4-116
®
.
The DVD Player supports:
Up to 255 folders.
Up to 8 folders in depth.
Up to 15 playlists.
Up to 40 sessions.
Playlists with an .m3u or .wpl extension.
Files with an .mp3, .wma, or .cda file extension.
The CD Player supports:
Up to 512 files and folders.
Up to 8 folders in depth.
Playlists with an .m3u or .wpl extension.
Files with an .mp3, .wma, or .cda file extension.