Properties:
| Name | Value | Type | Description | 
|---|---|---|---|
| KEEP | keep | string | Never reset MediaSource when crossing boundary. | 
| RESET | reset | string | Always reset MediaSource when crossing boundary. | 
| RESET_TO_ENCRYPTED | reset_to_encrypted | string | Reset MediaSource once, when transitioning from a plain boundary to an encrypted boundary. | 
| RESET_ON_ENCRYPTION_CHANGE | RESET_ON_ENCRYPTION_CHANGE | string | Reset MediaSource, when transitioning from a plain boundary to an encrypted boundary or from an encrypted boundary to a plain boundary. |