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
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" audioTrackFormatName="PCM_FrontLeft" formatDefinition="PCM" formatLabel="0001"> <audioStreamFormatIDRef>AS_00010001</audioStreamFormatIDRef> </audioTrackFormat>
|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.
|audioStreamFormatIDRef||Reference to an audioStreamFormat||AS_00010001||1|