
The position tracker has two different position sources, getPlaybackHeadPosition and getTimestamp. Whenever we switch between these sources, we smooth out the position differences over a period of one second. This has two problems: 1. The smoothing duration is 1 sec regardless of the actual position difference. So for small differences, assuming the new timestamp is more correct, we needlessly keep the tracker with a position offset for longer. For large differences, the smoothing may result in an extremely large speedup (up to 5x in theory, for a max allowed diff of 5 seconds smoothed over a 1 second real time period). The solution to this issue is to adjust the smoothing period to the actual difference by using a maximum speedup/slowdown set to 10% at the moment. Smaller differences are corrected faster and larger differences are corrected in a slightly smoother way without speeding up drastically. We still need an upper bound though (set to 1 second difference) where plainly jumping to the correct position is likely a better user experience than having a lenghty smoothing. 2. The smoothing is only applied when switching between position sources. That means any position drift or jump coming from the same source is always taken as it is without any smoothing. This is problematic for the getTimstamp-based position in particular as it is only sampled every 10 seconds. The solution to this problem is to entirely remove the condition that smoothing only happens when switching between position sources. Instead we can always check whether the position drift compared to the last known position is more than the maximum allowed speedup/slowdown of 10% and if so, start applying smoothing. This helps to smooth out the position progress at the start of playback and after resumption when we switch between the position sources and both sources are not super reliable yet and it also helps for unexpected jumps in the position of getTimestamp later on during playback. PiperOrigin-RevId: 755348271
AndroidX Media
AndroidX Media is a collection of libraries for implementing media use cases on Android, including local playback (via ExoPlayer), video editing (via Transformer) and media sessions.
Documentation
- The developer guide provides a wealth of information.
- The class reference documents the classes and methods.
- The release notes document the major changes in each release.
- The media dev center provides samples and guidelines.
- Follow our developer blog to keep up to date with the latest developments!
Migration for existing ExoPlayer and MediaSession projects
You'll find a migration guide for existing ExoPlayer and MediaSession users on developer.android.com.
API stability
AndroidX Media releases provide API stability guarantees, ensuring that the API surface remains backwards compatible for the most commonly used APIs. APIs intended for more advanced use cases are marked as unstable. To use an unstable method or class without lint warnings, you’ll need to add the OptIn annotation before using it. For more information see the UnstableApi documentation.
Using the libraries
You can get the libraries from the Google Maven repository. It's also possible to clone this GitHub repository and depend on the modules locally.
From the Google Maven repository
1. Add module dependencies
The easiest way to get started using AndroidX Media is to add gradle
dependencies on the libraries you need in the build.gradle.kts
file of your
app module.
For example, to depend on ExoPlayer with DASH playback support and UI components you can add dependencies on the modules like this:
implementation("androidx.media3:media3-exoplayer:1.X.X")
implementation("androidx.media3:media3-exoplayer-dash:1.X.X")
implementation("androidx.media3:media3-ui:1.X.X")
Or in Gradle Groovy DSL build.gradle
:
implementation 'androidx.media3:media3-exoplayer:1.X.X'
implementation 'androidx.media3:media3-exoplayer-dash:1.X.X'
implementation 'androidx.media3:media3-ui:1.X.X'
where 1.X.X
is your preferred version. All modules must be the same version.
Please see the AndroidX Media3 developer.android.com page for more information, including a full list of library modules.
This repository includes some modules that depend on external libraries that need to be built manually, and are not available from the Maven repository. Please see the individual READMEs under the libraries directory for more details.
2. Turn on Java 8 support
If not enabled already, you also need to turn on Java 8 support in all
build.gradle.kts
files depending on AndroidX Media, by adding the following to
the android
section:
compileOptions {
targetCompatibility = JavaVersion.VERSION_1_8
}
Or in Gradle Groovy DSL build.gradle
:
compileOptions {
targetCompatibility JavaVersion.VERSION_1_8
}
Locally
Cloning the repository and depending on the modules locally is required when
using some libraries. It's also a suitable approach if you want to make local
changes, or if you want to use the main
branch.
First, clone the repository into a local directory:
git clone https://github.com/androidx/media.git
Next, add the following to your project's settings.gradle.kts
file, replacing
path/to/media
with the path to your local copy:
(gradle as ExtensionAware).extra["androidxMediaModulePrefix"] = "media3-"
apply(from = file("path/to/media/core_settings.gradle"))
Or in Gradle Groovy DSL settings.gradle
:
gradle.ext.androidxMediaModulePrefix = 'media3-'
apply from: file("path/to/media/core_settings.gradle")
You should now see the AndroidX Media modules appear as part of your project.
You can depend on them from build.gradle.kts
as you would on any other local
module, for example:
implementation(project(":media3-lib-exoplayer"))
implementation(project(":media3-lib-exoplayer-dash"))
implementation(project(":media3-lib-ui"))
Or in Gradle Groovy DSL build.gradle
:
implementation project(':media3-lib-exoplayer')
implementation project(':media3-lib-exoplayer-dash')
implementation project(':media3-lib-ui')
MIDI module
By default the MIDI module is disabled as a local
dependency, because it requires additional Maven repository config. If you want
to use it as a local dependency, please configure the JitPack repository as
described in the module README,
and then enable building the module in your settings.gradle.kts
file:
gradle.extra.apply {
set("androidxMediaEnableMidiModule", true)
}
Or in Gradle Groovy DSL settings.gradle
:
gradle.ext.androidxMediaEnableMidiModule = true
Developing AndroidX Media
Project branches
Development work happens on the main
branch. Pull requests should normally be
made to this branch.
The release
branch holds the most recent stable release.
Using Android Studio
To develop AndroidX Media using Android Studio, simply open the project in the root directory of this repository.