# GCKMediaTrack Class

[Instance Methods](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#pub-methods) \| [Properties](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#properties) GCKMediaTrack Class Reference

## Overview

A class representing a media track.

Instances of this object are immutable.

Inherits NSObject, \<NSCopying\>, and \<NSSecureCoding\>.

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| ## Instance Method Summary ||
| (nullable instancetype) | - [initWithIdentifier:contentIdentifier:contentType:type:textSubtype:name:languageCode:customData:](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#ad7168da70752272fce29a2ad89cad78c) |
|   | Designated initializer. [More...](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#ad7168da70752272fce29a2ad89cad78c) |
|   ||

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| ## Property Summary ||
| NSInteger | [identifier](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#add043f7b6491150d5d45c6e930bbe175) |
|   | The track's unique numeric identifier. [More...](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#add043f7b6491150d5d45c6e930bbe175) |
|   ||
| NSString \* | [contentIdentifier](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#a1745215ffd1536f05b9fceb75039bd0b) |
|   | The track's content identifier, which may be `nil`. [More...](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#a1745215ffd1536f05b9fceb75039bd0b) |
|   ||
| NSString \* | [contentType](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#a3fe538179a734bf44678d00d6b981439) |
|   | The track's content (MIME) type. [More...](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#a3fe538179a734bf44678d00d6b981439) |
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| GCKMediaTrackType | [type](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#af981743cc15c5370852a8e1da77bb89d) |
|   | The track's type. [More...](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#af981743cc15c5370852a8e1da77bb89d) |
|   ||
| [GCKMediaTextTrackSubtype](https://developers.google.com/cast/docs/reference/ios/g_c_k_media_track_8h#a1e497c8baed0344312dd2d3761aae675) | [textSubtype](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#a8c76840f4423729666abc7200f02d65b) |
|   | The text track's subtype; applies only to text tracks. [More...](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#a8c76840f4423729666abc7200f02d65b) |
|   ||
| NSString \* | [name](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#a7905ff600efb4bf2bf034234c6563cb2) |
|   | The track's name, which may be `nil`. [More...](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#a7905ff600efb4bf2bf034234c6563cb2) |
|   ||
| NSString \* | [languageCode](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#af6c124e209ef42e8abd48be44f1aa4f4) |
|   | The track's RFC 1766 language code, which may be `nil`. [More...](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#af6c124e209ef42e8abd48be44f1aa4f4) |
|   ||
| id | [customData](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#a7141568f51722edd83e6c1f593f0c821) |
|   | The custom data, if any. [More...](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track#a7141568f51722edd83e6c1f593f0c821) |
|   ||

## Method Detail

|---|---|---|---|
| - (nullable instancetype) initWithIdentifier: |   | (NSInteger) | *identifier* |
| contentIdentifier: |   | (nullable NSString \*) | *contentIdentifier* |
| contentType: |   | (NSString \*) | *contentType* |
| type: |   | (GCKMediaTrackType) | *type* |
| textSubtype: |   | ([GCKMediaTextTrackSubtype](https://developers.google.com/cast/docs/reference/ios/g_c_k_media_track_8h#a1e497c8baed0344312dd2d3761aae675)) | *textSubtype* |
| name: |   | (nullable NSString \*) | *name* |
| languageCode: |   | (nullable NSString \*) | *languageCode* |
| customData: |   | (nullable id) | *customData* |
|   |   |   |   |

Designated initializer.

Constructs a new [GCKMediaTrack](https://developers.google.com/cast/docs/reference/ios/interface_g_c_k_media_track "A class representing a media track. ") with the given property values. Can return a `nil` value.

## Property Detail

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| |---| | - (NSInteger) identifier | | readnonatomicassign |

The track's unique numeric identifier.

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| |---| | - (NSString\*) contentIdentifier | | readnonatomiccopy |

The track's content identifier, which may be `nil`.

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| |---| | - (NSString\*) contentType | | readnonatomiccopy |

The track's content (MIME) type.

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| |---| | - (GCKMediaTrackType) type | | readnonatomicassign |

The track's type.

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| |---| | - ([GCKMediaTextTrackSubtype](https://developers.google.com/cast/docs/reference/ios/g_c_k_media_track_8h#a1e497c8baed0344312dd2d3761aae675)) textSubtype | | readnonatomicassign |

The text track's subtype; applies only to text tracks.

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| |---| | - (NSString\*) name | | readnonatomiccopy |

The track's name, which may be `nil`.

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| |---| | - (NSString\*) languageCode | | readnonatomiccopy |

The track's RFC 1766 language code, which may be `nil`.

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| |---| | - (id) customData | | readnonatomicstrong |

The custom data, if any.

Must either be an object that can be serialized to JSON using [**NSJSONSerialization**](https://goo.gl/0vd4Q2), or `nil`.