# Content part

The ADM can be divided in the content and the format part. The format part can exist without the content part, but not the other way around. Here we'll go through the content part with some simple examples.

## Single Programme

In many situations the ADM file you'll be generating will be for a single programme. A programme is the top level of the ADM, and the audioProgramme element is used to describe it. As with the other ADM main elements, we can give the audioProgramme a name, an ID, some time-related information and some other useful parameters. But lets start with the most basic settings, with name and ID set (both are mandatory):

<audioProgramme audioProgrammeName="Documentary"
audioProgrammeID="APR_1001">
</audioProgramme>


This doesn't really tell us much, but it provides an entry point into the ADM, from which further things can be referenced. What we can add at this stage is the start and duration of the programme, so let's make it 30 minutes long:

<audioProgramme audioProgrammeName="Documentary"
audioProgrammeID="APR_1001"
start="00:00:00.00000" duration="00:30:00.00000">
</audioProgramme>


## Describing the Content

So, what have we got in our programme? In this example, we've got some narration, sound effects and background music. These are not described in the audioProgramme, but in the next element: audioContent.

For example, we can generate three audioContent elements, and give them some suitable names and IDs. Another thing we can add to each of these three elements is some information about whether the audio is dialogue or not:

<audioContent audioContentName="Narration"
audioContentID="ACO_1001">
<dialogue dialogueContentKind="1">1</dialogue>
</audioContent>
<audioContent audioContentName="SoundFX"
audioContentID="ACO_1002">
<dialogue nonDialogueContentKind="2">0</dialogue>
</audioContent>
<audioContent audioContentName="BgMusic"
audioContentID="ACO_1003">
<dialogue nonDialogueContentKind="1">0</dialogue>
</audioContent>


Now that we've defined these three audioContent elements, we need the audioProgramme element to be able to see them. This is done by adding some ID references to the audioProgramme element:

<audioProgramme audioProgrammeName="Documentary"
audioProgrammeID="APR_1001"
start="00:00:00.00000" duration="00:30:00.00000">
<audioContentIDRef>ACO_1001</audioContentIDRef>
<audioContentIDRef>ACO_1002</audioContentIDRef>
<audioContentIDRef>ACO_1003</audioContentIDRef>
</audioProgramme>


So our elements are now structured like this:

## Connecting the Content Description to the Audio

We've now got three audioContent elements that each describe part of our programme, but these content descriptions need some actual audio connected to them. This is where the 'audioObject' element comes in. This element references audio tracks and the format description for those tracks, and can be referenced from the audioContent element.

Let's make some audioObject element for our example, we'll generate three of them, one for each audioContent element:

<audioObject audioObjectName="Narration"
audioObjectID="AO_1001">
<audioPackFormatIDRef>AP_00031001</audioPackFormatIDRef>
<audioTrackUIDRef>ATU_00000001</audioTrackUIDRef>
</audioObject>
<audioObject audioObjectName="SoundFX"
audioObjectID="AO_1002">
<audioPackFormatIDRef>AP_00010003</audioPackFormatIDRef>
<audioTrackUIDRef>ATU_00000002</audioTrackUIDRef>
<audioTrackUIDRef>ATU_00000003</audioTrackUIDRef>
<audioTrackUIDRef>ATU_00000004</audioTrackUIDRef>
<audioTrackUIDRef>ATU_00000005</audioTrackUIDRef>
<audioTrackUIDRef>ATU_00000006</audioTrackUIDRef>
<audioTrackUIDRef>ATU_00000007</audioTrackUIDRef>
</audioObject>
<audioObject audioObjectName="BgMusic"
audioObjectID="AO_1003">
<audioPackFormatIDRef>AP_00010002</audioPackFormatIDRef>
<audioTrackUIDRef>ATU_00000008</audioTrackUIDRef>
<audioTrackUIDRef>ATU_00000009</audioTrackUIDRef>
</audioObject>


In each object there is an audioPackFormatIDRef sub-element, and this is a reference to an audioPackFormat element that describes the format of the group of channels the audio has. There are also some audioTrackUIDRef sub-elements, and these are references to the actual track of audio. So for each of the three objects we have these references:

• Narration (AO_1001)
• Pack: AP_00031001 - 'Object' type containing a single channel
• Track UID: ATU_00000001 - Single track
• SoundFX (AO_1002)
• Pack: AP_00010003 - 'DirectSpeakers' type containing a 5.1 set of channels
• Track UIDs: ATU_00000002 to ATU_00000007 - Six tracks
• BgMusic (AO_1003)
• Pack: AP_00010002 - 'DirectSpeakers' type containing a stereo pair of channels
• Track UIDs: ATU_00000008 and ATU_00000009 - Two tracks

We can now go back and connect our audioContent elements to the audioObject elements:

<audioContent audioContentName="Narration"
audioContentID="ACO_1001">
<dialogue dialogueContentKind="1">1</dialogue>
<audioObjectIDRef>AO_1001</audioObjectIDRef>
</audioContent>
<audioContent audioContentName="SoundFX"
audioContentID="ACO_1002">
<dialogue nonDialogueContentKind="2">0</dialogue>
<audioObjectIDRef>AO_1002</audioObjectIDRef>
</audioContent>
<audioContent audioContentName="BgMusic"
audioContentID="ACO_1003">
<dialogue nonDialogueContentKind="1">0</dialogue>
<audioObjectIDRef>AO_1003</audioObjectIDRef>
</audioContent>


So, we have now generated a description of our content and connected to the format description via the audioPackFormatIDRef sub-elements within audioObject. The audioObject element also contains other parameters to allow setting of time restrictions (more can be read on the Timing page), interactivity and mutual exclusivity.

Our elements are now structured like this:

You should have already seen the audioPackFormat elements in the format part page, so you can now see how the format part connects with the content part.

## Track UIDs and Actual Audio Tracks

In the audioObject element you'll see the audioTrackUIDRef sub-elements, which reference audioTrackUID elements. The audioTrackUID element represents part of, or a complete, audio track in the file. In its simplest form it doesn't have to carry any other information, but it can include the sample-rate and bit-depth used if wanted.

In a BW64 the 'chna' chunk carries the relationship between audioTrackUIDs and the actual tracks in the file like this:

TrackNum audioTrackUID audioTrackFormatID audioPackFormatID
1 ATU_00000001 AT_00031001_01 AP_00031001
2 ATU_00000002 AT_00010001_01 AP_00010003
3 ATU_00000003 AT_00010002_01 AP_00010003
4 ATU_00000004 AT_00010003_01 AP_00010003
5 ATU_00000005 AT_00010004_01 AP_00010003
6 ATU_00000006 AT_00010005_01 AP_00010003
7 ATU_00000007 AT_00010006_01 AP_00010003
8 ATU_00000008 AT_00010001_01 AP_00010002
9 ATU_00000009 AT_00010002_01 AP_00010002

So, you can see how the 9 audio tracks in the file are each given an audioTrackUID ID, as well as audioTrackFormatID and audioPackFormatIDs which describe the format of each tracks.