The audioTrackFormat element corresponds to a single set of samples or data in a single track in a storage medium. It is used to describe what format the data is in, allowing a renderer to decode the signal correctly. It is referred from the audioStreamFormat element, which is used to identify the combination of tracks required to decode the track data successfully.

For PCM audio an audioStreamFormat will refer to a single audioTrackFormat and so the two elements are effectively describing the same thing. For coded audio, multiple audioTrackFormats will have to be combined in a single audioStreamFormat to generate decodable data.

Software that parses the model can start from either audioTrackFormat or audioStreamFormat. To allow for this flexibility audioTrackFormat can also refer back to the audioStreamFormat. However, it is a strict requirement that if this reference is used, the audioTrackFormat must refer to the same audioStreamFormat that is referring back to it.


<audioTrackFormat audioTrackFormatID="AT_00010001_01"
                  formatDefinition="PCM" formatLabel="0001">


Attribute Description Example Required
audioTrackFormatName Name of the track PCM_FrontLeft Yes
audioTrackFormatID ID for track. The yyyy digits of AT_yyyyxxxx_nn represent the type of audio contained in the track. The yyyyxxxx digits should match the audioStreamFormat yyyyxxxx digits. The nn digits represent the track number (starting at 1) within the stream. AT_00010001_01 Yes
formatLabel Descriptor of the format 0001 Optional
formatDefinition Description of the format PCM Optional

* At least one of formatLabel or formatDefinition is required.


Element Description Example Quantity
audioStreamFormatIDRef Reference to an audioStreamFormat AS_00010001 1