Audio File Compatibility

There are a number of variables that can be set (either automatically or by the user) at the point of creating the audio file that may contribute to an audio file being encoded in an incompatible format. These include:

• The type of audio file  created (eg: MP3/WMA/AAC)
• The specification of Variable Bit Rate  (VBR) or Constant Bit Rate  (CBR) encoding
• If CBR encoding is being used, then a particular bit rate value (measured in kilobits per second - kbps) may be selected
• The rate of sampling frequency  , measured in kilohertz (kHz), may also be selected

The system shall support a number of various audio and video codecs (outlined in a later paragraph), but if the user has used a software tool to create their own media file outside of the codec's specification, then successful playback cannot be guaranteed.

Diagnostic Procedures For Audio Files 

Identify File Type:  if a customer reports issues with audio file playback, first confirm that the data source is operating normally and is not locked or corrupted. This may be achieved by reading the USB storage device or data disk via a PC and confirming that the audio files can be seen/accessed as expected. If the storage device/data disk appears to be operating normally, the next step is to ascertain the file type of those files that will not play through the infotainment system. The infotainment system supports the following audio file formats:

• MP3
• WMA
• WAV
• AIFF
• M4A
• FLAC
• AAC
• AMR
• PCM
• ALAC

The system pre-filters out non-supported audio file formats, therefore media files which are presented to the user, should be playable.

Playback Of Audio Files Stored On The Internal Storage Or A USB Storage Device 

Further information about the audio file may be accessed via the file properties tab either when viewing the file in Windows Explorer or when playing the file via a digital media player programme. In such a way, it should be possible to ascertain some or all of the required information concerning the file's specified encoding type/bit rate/sampling frequency. Once this information has been obtained, use the tables detailed below to check if the suspect audio file is compatible with the vehicle infotainment system.