Background Audio Overview

The following compose the three main classes used for background audio, which are explored in this chapter:

BackgroundAudioPlayer

AudioPlayerAgent

AudioStreamingAgent

BackgroundAudioPlayer is a class that allows you to specify an audio file for playback and to carry out playback activities such as play, pause, fast-forward, and rewind. BackgroundAudioPlayer allows you to specify track information, such as the title of the track and its location. The built-in playback capabilities of the BackgroundAudioPlayer allow audio files to be streamed from either a remote server, or locally, from isolated storage.

Out of the box, BackgroundAudioPlayer supports playback formats such as MP3, WMA, and WAV. For a complete list of supported audio formats, see http://bit.ly/pnnT8C. BackgroundAudioPlayer offers little in the way of coordinating the playback of a list of audio tracks. This is the task of the AudioPlayerAgent.

AudioPlayerAgent classes are specialized agents used to retrieve audio files and coordinate the playback of background audio via the BackgroundAudioPlayer. AudioPlayerAgent provides a number of method callbacks that are automatically called by the OS based on user actions.

An AudioStreamingAgent can be used to customize how audio data is procured by your BackgroundAudioPlayer. You can supplant the BackgroundAudioPlayer’s media sourcing capabilities by providing your own logic to download and decode an audio file.