Transformer demo application

The Transformer demo app lets you try out the API's capabilities and transform your own media, including converting media between formats, trimming, and applying video effects.

This page describes how to get, compile, and run the demo app. This guide also describes how to use the demo app to transform your own media.

Get the code

The source code for the main demo app can be found in the demos/transformer folder of the GitHub project. If you haven't already done so, clone the project into a local directory:

git clone

Next, open the project in Android Studio. You should see the following in the Android Project view (the relevant folders of the demo app have been expanded):

The project in Android Studio
The project in Android Studio

Compile and run the demo

To compile and run the demo app, select and run the demo-transformer configuration in Android Studio. The demo app will install and run on a connected Android-powered device. We recommend using a physical device if possible, because typically an emulator's implementation of Android's media stack has different capabilities and bugs compared to a real device.

Demo app configuration activity
Demo app configuration activity

The demo app begins with the ConfigurationActivity, an activity where you can set up the input media item and the transformation you want to perform. The two buttons at the top of the screen let you choose from a list of preset media files or pick a local file. Next, the scrollable list of options lets you configure the output format and transformations, and you can select effects to apply to the media. Tapping the last button transitions to TransformerActivity, an activity that shows the current progress and a preview of frames as they are passing through Transformer. Once transformation completes, the input and output videos are shown together in two ExoPlayer PlayerView instances.

Transform your own content

The demo app supports selecting media for transformation using the buttons at the top of the configuration screen. You can also pass a URL directly on the command line:

adb shell am start -a androidx.media3.demo.transformer.action.VIEW \

MediaPipe integration

The demo app includes an example integration with MediaPipe. You will need to build the dependency manually, then select the withMediaPipe build variant to enable building the app with the media pipe frame processor. See the README for full instructions. The effects selector in the configuration activity includes an example MediaPipe-based effect to try this out.