Media3 overview

Jetpack Media3 is the new home for media libraries that enables Android apps to display rich audio and visual experiences. It introduces a simpler architecture that is familiar to current developers, and which allows you to more easily build and maintain your apps. Media3 also includes ExoPlayer as the default player implementation.

This document provides an introduction to the changes that Media3 introduces and directs you onwards to other Media3 docs.

Components

A media app that uses Media3 is comprised of several key components. The classes that make up these components will be familiar to you if you have worked with previous Android media libraries.

Class	Description	Implementation note
MediaSession	Media sessions enable your app to interact with an audio or video player. They advertise media playback externally and receive playback commands from external sources.	In Media3, the MediaSession takes the player directly.
Player	The player is an interface that defines traditional high-level functionality, such as the ability to play, pause, and seek.	In Media3, the default Player implementation is ExoPlayer.
MediaSessionService/MediaLibraryService	The MediaSessionService holds a media session and its associated player in a service separate from your application main Activity. This facilitates background playback. Use a MediaLibraryService instead to additionally expose your content library to client apps.
MediaController	The MediaController class is generally used to send commands from outside your app, for example from other apps or the system itself. The commands are sent to the underlying Player of the associated MediaSession.	The MediaController class implements the Player interface, but when calling a method the command gets sent to the connected MediaSession. For this reason, client apps like the Google Assistant generally implement MediaController.
MediaBrowser	The MediaBrowser class allows the user to navigate through media content and select which items to play.	The MediaBrowser class implements both the MediaController and Player interfaces. Same as MediaController, client apps such as Android Auto generally implement MediaBrowser.

The following diagram clearly delineates how these components come together in a typical app.

Figure 1: Media app components

Important: One of the primary characteristics that distinguishes Media3 from previous media APIs is that there is no longer a need for connectors between components. The new MediaSession class takes any class that implements the Player interface, as can the UI. Both ExoPlayer and MediaController are classes which implement that interface. This facilitates much simpler interaction between the components.

Documentation

For the Media3 beta release, you will find a series of documents that examine in detail some of the key features in Media3. Namely, these documents outline how media sessions and media controllers now interact with the ExoPlayer class and Player interface, as this is perhaps the key difference between Media3 and previous media APIs.

When Media3 reaches its stable release, these documents will expand to cover the full breadth of the Media3 API and how to best implement it.

Media sessions

Media sessions are a crucial component to any media app. The key change to media sessions in Media3 is that the MediaSession class now directly takes a Player, such as ExoPlayer. This reduces the need for connectors, such as the MediaSessionConnector from the previous exoplayer2 library, and both simplifies and deepens the interaction between the MediaSession class and other core classes like MediaController.

For more information, read this guide that covers how you can use the Media3 media sessions to control and advertise playback within your app.

Background playback

It is very common for media apps to play media in the background, such as with music apps, or video apps that offer picture-in-picture. This is achieved with a separate MediaSessionService.

For more information, please see the Media3 background playback guide.

ExoPlayer

ExoPlayer is at the core of Media3 as the chosen implementation for the API’s media player. To facilitate this, ExoPlayer is now an AndroidX library. This means that it now has an API surface that will remain stable through future upgrades. It is therefore far easier to upgrade between new versions of ExoPlayer.

For the primary ExoPlayer documentation, see About Media3 ExoPlayer.

Note: While Media3’s implementation of ExoPlayer is not very different from the current independent version, the package names have changed. For more information, please see the ExoPlayer to Media3 mappings.

Transformer

Media3 includes Transformer for converting and editing media files. See the transformer guide pages for more information.

Introduction video

See the video below for an introduction to Media3 from the engineers who built it.

Useful links

• Existing media docs
• AndroidX Media3 on GitHub
• Media3 media session sample app
• Universal Android Music Player sample app