PRXPlayer currently depends on a modified Reachability.

pod 'PRXPlayer', '~> 2.0'

PRXPlayer is a lightweight wrapper around AVPlayer. It's job is simply to provide a standard set of tools, for free, that most implementations of an media player would have anyway. This includes things like: retry logic, error handling, observing basic state changes, and monitoring playback. PRXPlayer provides an abstracted set of NSNotifications, which make it easy for your app to respond to nearly all relevant changes. More precise interaction with the AVPlayer and its items and assets can be achieved by implementing a PRXPlayerDelegate. Beyond that, you always have the ability to deal with the underlying AVPlayer instances directly, allowing for as much customization as you need.

The PRXPlayer API expects objects that implement the PRXPlayerItem protocol. This protocol ensures that objects contain the most basic set of properties that are required for a consistent media player experience. Every PRXPlayerItem must provide an AVAsset, which is what actually gets loaded into the underlying AVPlayer, and implement the isEqualToPlayerItem: to the player can accurately determine when player items have changed.

In some cases, the AVAsset of a given object may change over time. For instance, an episode object may by default have an AVURLAsset corresponding to a file on a remote server, but then returns an AVURLAsset corresponding to a file in local storage after the episode has been downloaded. In cases such as this, isEqualToPlayerItem: should be able to distnguish between these various situations, and return NO when a PRXPlayerItem is compared to itself, but with differing AVAssets.

There are two groups of methods that a PRXPlayer has to allow for controlling playback: indifferent and explicit. The indifferent methods are: play, pause, toggle, and stop. These control the player regardless of what is loaded into the player. The explict controls, playPlayerItem:, loadPlayerItem:, and togglePlayerItem: deal with specific media objects. If an explict control message is sent to a PRXPlayer and the given object is not the currently loaded object, the player will take steps to clear out any existing media object and load the new one. loadPlayerItem: will prepare a media object as much as possible, up until the point where it can begin playback (ie it will start to buffer), but will keep the player paused once it's ready.

Work in progress…

One of the primary functions of PRXPlayer is to make responding to changes for an AVPlayer and the associated media very easy. One way this is accomplished is by posting several very general notifications as changes come about. In most cases, parts of an app (eg UI elements, persistance layers, etc) are not concerned with what changed or what caused the change, simply that the change occured.

A common example would be the player controls UI presented in a music app. The controller managing the UI does not necessarily care why the player became paused, simply that the player changed state, and that the UI should be updated.

PRXPlayer will post a PRXPlayerChangeNotification any time the state of the player, it's underlying AVPlayer, or an asset loaded into the AVPlayer changes. Observing this notification, using the sharedPlayer as the object, should cover all situations needed to keep a player UI in sync with the player.

Additionally the PRXPlayerTimeIntervalNotification and PRXPlayerLongTimeIntervalNotification will be posted at one and 10 second intervals respectively any time playback is occuring through the PRXPlayer. Time jumps will also cause these notifications to be posted. For general use, the object registered for these notifications should be the sharedPlayer.

In cases where the asset that is playing back is an AVURLAsset, two additional notifications will be posted. They are also PRXPlayerTimeIntervalNotification and PRXPlayerLongTimeIntervalNotification notifications, but the object is the absoluteString of the URL of the AVURLAsset.

PRXPlayer also allows for the enforcement of WWAN (eg 3G/4G cellular connection) policy, and will post a PRXPlayerReachabilityPolicyPreventedPlayback if playback fails due to network connectivity conditions.