2010 Mercedes C-Class Owner's Manual - Page 162

160 Audio system File structure on a disc When you create an MP3/WMA disc, the MP3/WMA tracks can be organized in folders. A folder can also contain other folders. A disc can contain a maximum of 255 folders. A folder can contain a maximum of 255 tracks and 255 subfolders. A data medium may contain a maximum of 500 tracks. The directory depth may not exceed a maximum of 8 levels. The system will ignore files in lower levels. Track and folder names When you create an MP3/WMA disc, you can assign names to the MP3/WMA tracks and folders. The audio system uses these names for the corresponding display in MP3 mode. Empty folders or folders which contain data other than MP3/WMA tracks are not displayed by the audio system. If MP3/WMA files are saved in the root directory itself (uppermost directory on storage medium), the root directory will also be treated as a folder. The audio system will then show the name of the root directory as the folder name. You must observe the following when assigning track names: RTrack RTrack i The audio system does not support ID3 tags. Supported file formats Supported file formats are: RMP3 RWMA Controls in detail i If music files of file formats other than MP3 are stored together with MP3 files on one disc, the loading process may take longer. Permissible MP3 formats The audio system supports the MPEG1 Audio Layer 3 format. i This format is generally known as "MP3". Permissible bit and sampling rates are: Rfixed and variable bit rates up to 320 kbit/s RSampling rates of 24 kHz - 48 kHz i Only use MP3 tracks with a bit rate of at least 128 kbit/s or higher and a sampling rate of at least 44.1 kHz or higher. Smaller rates can cause a noticeable deterioration in sound quality. This is especially the case if you have the surround sound function activated. WMA (Windows Media® Audio) Windows Media® Audio (WMA) is an audio data compression technology developed by Microsoft®. The audio system supports the following types of audio files: Rfixed bit rates of 5 kbit/s up to 384 kbit/s RSampling names must have at least one character. names must have the extension "mp3" or "wma". must be a period between the track name and the extension. Example of a correct track name: Track1.mp3 RThere rates from 8 kHz to 48 kHz The audio system is unable to recognize an MP3/WMA track if Rthere Rthere is no period between the track title and the extension is no extension The audio system does not support the following WMA files: RDRM (Digital Rights Management) coded files Rvariable bit rates