MPTimedMetadata Class Reference

Inherits from	NSObject
Conforms to	NSObject (NSObject)
Framework	/System/Library/Frameworks/MediaPlayer.framework
Availability	Available in iOS 4.0 and later.
Declared in	MPMoviePlayerController.h

Overview

An instance of the MPTimedMetadata class, called a timed metadata object, carries time-based information within HTTP streamed media. Content providers can embed such objects when creating a stream. The properties and constants in this class let you extract the metadata as you play the stream using an MPMoviePlayerController object.

For example, the provider of a live sports video stream could use MPTimedMetadata instances to embed game scores, with timestamps, in the stream. On the client side—that is, on the user’s device—their application could employ the properties of this class to update their app’s user interface in real time during the game.

A Javascript implementation of this class is also available for use by web-based applications.

Tasks

Extracting Timed Metadata from a Stream

Properties

allMetadata

A dictionary containing all the metadata in the object. (read-only)

@property (nonatomic, readonly) NSDictionary *allMetadata

Discussion

To retrieve metadata from the dictionary, use the keys described in “Timed Metadata Dictionary Keys.”

Availability

Available in iOS 4.0 and later.

Declared In

MPMoviePlayerController.h

key

A key that identifies a piece of timed metadata. (read-only)

@property (nonatomic, readonly) NSString *key

Availability

Available in iOS 4.0 and later.

Declared In

MPMoviePlayerController.h

keyspace

The namespace of the identifying key. (read-only)

@property (nonatomic, readonly) NSString *keyspace

Availability

Available in iOS 4.0 and later.

Declared In

MPMoviePlayerController.h

timestamp

The timestamp of the metadata, in the timebase of the media stream. (read-only)

@property (nonatomic, readonly) NSTimeInterval timestamp

Availability

Available in iOS 4.0 and later.

Declared In

MPMoviePlayerController.h

value

The timed metadata. (read-only)

@property (nonatomic, readonly) id value

Availability

Available in iOS 4.0 and later.

Declared In

MPMoviePlayerController.h

Constants

Timed Metadata Dictionary Keys

Dictionary keys for use with the allMetadata property. All keys are optional.

NSString *const MPMoviePlayerTimedMetadataKeyName;
NSString *const MPMoviePlayerTimedMetadataKeyInfo;
NSString *const MPMoviePlayerTimedMetadataKeyMIMEType;
NSString *const MPMoviePlayerTimedMetadataKeyDataType;
NSString *const MPMoviePlayerTimedMetadataKeyLanguageCode;