# audioTrackUID

## Description

The audioTrackUID uniquely identifies a track or asset within a file or recording of an audio scene. This element contains information about the bit depth and sample rate of the track. It also contains sub-elements that allow the model to be used for non-BW64 applications by performing the job of the 'chna' chunk. When using the model with MXF files the audioMXFLookUp sub-element (which contains sub-elements to refer to the audio essences in the file) is used.

## Example

<audioTrackUID UID="ATU_00000001" sampleRate="48000" bitDepth="24">
<audioTrackFormatIDRef>AT_00010001_01</audioTrackFormatIDRef>
<audioPackFormatIDRef>AP_00010002</audioPackFormatIDRef>
</audioTrackUID>


## Attributes

Attribute Description Example Required
UID The actual UID value ATU_00000001 Yes
sampleRate Sample rate of track in Hz 48000 Optional
bitDepth Bit depth of track in bit 24 Optional

## Sub-elements

Element Description Example Quantity
audioMXFLookUp See audioMXFLookUp sub-section 0 or 1
audioTrackFormatIDRef Reference to an audioTrackFormat description AT_00010001_01 0 or 1
audioPackFormatIDRef Reference to an audioPackFormat description AP_00010002 0 or 1

### audioMXFLoopUp sub-elements

MXF has different meanings for the terms ‘track’ and ‘channel’ from their use in the ADM. In MXF ‘track’ is the storage medium containing audio or video, and for audio this ‘track’ can be sub-divided into ‘channels’.

Element Description Type Example
packageUIDRef Reference to an MXF package UMID string urn:smpte:umid:060a2b34.01010105.01010f20.13000000.540bca53.41434f05.8ce5f4e3.5b72c985
trackIDRef Reference to an MXF track int MXFTRACK_3
channelIDRef Reference to a channel track int MXFCHAN_1