# Structures

The following structures are available globally.

### CastEngine

- `CastEngine`

  Cast engine

  See more

  #### Declaration

  Swift

      public struct CastEngine : RawRepresentable, Hashable

- `MetaData`

  The meta-data object is a dictionary that can contain arbitrary data.

  #### Declaration

  Swift

      public struct MetaData : Codable, Hashable

- `SideloadedTrack`

  This object describes a text or thumbnail track that can be side loaded.

  #### Declaration

  Swift

      public struct SideloadedTrack : Codable, Hashable