Audio Playback

The StreamChat framework ships with tools that enable you to playback any (supported) audio file.

note

Audio Playback, using an instance of AudioPlaying, is available since version 4.32.0.

An instance of AudioPlaying is responsible for handling all audio playback related operations and acts as a thin abstraction layer between your app and the AVPlayer system.

note

The SDK ships with 2 audio players out of the box, 1. StreamAudioPlayer and 2. StreamAudioQueuePlayer. As StreamAudioQueuePlayer is a simple sub-class of StreamAudioPlayer that extends its queue management capabilities, we will focus on the StreamAudioPlayer base class for now. ::::

The StreamAudioPlayer that ships with the SDK and implements the AudioPlaying protocol, can take care of the following responsibilities, additional to managing the audio playback of:

• Configure the AVAudioSession for recording.
• React on the application's state changes(move to background or foreground).
• Fetch remote properties of remote audio files (for example its duration).

StreamAudioPlayer follows a subscription model where in order to receive updates for playback, we need to subscribe on the player. Once subscribed we will start receiving events about the state of the playback.

Actions

StreamAudioPlayer and any instance that conforms to the AudioPlaying protocol has the following actions that we can call on them:

func loadAsset(from url: URL)

Instructs the player to load the asset from the provided URL and prepare it for streaming. If the player's current item has a URL that matches the provided one, then the player will try to play or restart the playback.

func play()

Begin the loaded asset's playback. If no asset has been loaded, the action has no effect.

func pause()

Pauses the loaded asset's playback. If non has been loaded or the playback hasn't started yet the action has no effect.

func stop()

Stop the loaded asset's playback. If non has been loaded or the playback hasn't started yet the action has no effect.

func updateRate(_:)

Updates the loaded asset's playback rate to the provided one.

func seek(to:)

Performs a seek in the loaded asset's timeline at the provided time.

Receiving updates

By calling subscribe(_ subscriber: AudioPlayingDelegate) we are subscribing to receive updates from the AudioPlaying instance. Those updates include information about:

• The URL for the loaded audio file.
• The duration and current playback time.
• The player's state.
• The playback's rate.
• A flag indicating if the player is currently seeking.

StreamAudioQueuePlayer

The StreamAudioQueuePlayer implementation is a sub-class of StreamAudioPlayer with additional queue management capabilities. It requires a data source that conforms to the AudioQueuePlayerDatasource protocol. Once the playback of an audio file finishes, the StreamAudioQueuePlayer will ask its data source for the next item to play. If the dataSource provide one, the new item will be automatically loaded to the player its playback will begin once ready.