This is the new *Amazon CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [Amazon CloudFormation User Guide](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::MediaTailor::PlaybackConfiguration LivePreRollConfiguration
<a name="aws-properties-mediatailor-playbackconfiguration-liveprerollconfiguration"></a>

The configuration for pre-roll ad insertion.

## Syntax
<a name="aws-properties-mediatailor-playbackconfiguration-liveprerollconfiguration-syntax"></a>

To declare this entity in your Amazon CloudFormation template, use the following syntax:

### JSON
<a name="aws-properties-mediatailor-playbackconfiguration-liveprerollconfiguration-syntax.json"></a>

```
{
  "[AdDecisionServerUrl](#cfn-mediatailor-playbackconfiguration-liveprerollconfiguration-addecisionserverurl)" : String,
  "[MaxDurationSeconds](#cfn-mediatailor-playbackconfiguration-liveprerollconfiguration-maxdurationseconds)" : Integer
}
```

### YAML
<a name="aws-properties-mediatailor-playbackconfiguration-liveprerollconfiguration-syntax.yaml"></a>

```
  [AdDecisionServerUrl](#cfn-mediatailor-playbackconfiguration-liveprerollconfiguration-addecisionserverurl): String
  [MaxDurationSeconds](#cfn-mediatailor-playbackconfiguration-liveprerollconfiguration-maxdurationseconds): Integer
```

## Properties
<a name="aws-properties-mediatailor-playbackconfiguration-liveprerollconfiguration-properties"></a>

`AdDecisionServerUrl`  <a name="cfn-mediatailor-playbackconfiguration-liveprerollconfiguration-addecisionserverurl"></a>
The URL for the ad decision server (ADS) for pre-roll ads. This includes the specification of static parameters and placeholders for dynamic parameters. Amazon Elemental MediaTailor substitutes player-specific and session-specific parameters as needed when calling the ADS. Alternately, for testing, you can provide a static VAST URL. The maximum length is 25,000 characters.  
*Required*: No  
*Type*: String  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`MaxDurationSeconds`  <a name="cfn-mediatailor-playbackconfiguration-liveprerollconfiguration-maxdurationseconds"></a>
The maximum allowed duration for the pre-roll ad avail. Amazon Elemental MediaTailor won't play pre-roll ads to exceed this duration, regardless of the total duration of ads that the ADS returns.  
*Required*: No  
*Type*: Integer  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)