GPU acceleration delegate with Interpreter API

Using graphics processing units (GPUs) to run your machine learning (ML) models can dramatically improve the performance and the user experience of your ML-enabled applications. On Android devices, you can enable a delegate and one of the following APIs:

• Interpreter API - this guide
• Native (C/C++) API - guide

This page describes how to enable GPU acceleration for LiteRT models in Android apps using the Interpreter API. For more information about using the GPU delegate for LiteRT, including best practices and advanced techniques, see the GPU delegates page.

Use GPU with LiteRT with Google Play services

The LiteRT Interpreter API provides a set of general purpose APIs for building a machine learning applications. This section describes how to use the GPU accelerator delegate with these APIs with LiteRT with Google Play services.

LiteRT with Google Play services is the recommended path to use LiteRT on Android. If your application is targeting devices not running Google Play, see the GPU with Interpreter API and standalone LiteRT section.

Add project dependencies (with .toml version catalog)

1. Update your project's libs.versions.toml file

[libraries]
...
tflite-gpu = { module = "com.google.ai.edge.litert:litert-gpu", version = "2.X.Y" }
tflite-gpu-api = { module = "com.google.ai.edge.litert:litert-gpu-api", version = "2.X.Y" }
...

1. Add project dependencies in the app's build.gradle.kts

dependencies {
  ...
  implementation(libraries.tflite.gpu)
  implementation(libraries.tflite.gpu.api)
  ...
}

Add project dependencies

To enable access to the GPU delegate, add com.google.android.gms:play-services-tflite-gpu to your app's build.gradle file:

dependencies {
    ...
    implementation 'com.google.android.gms:play-services-tflite-java:16.0.1'
    implementation 'com.google.android.gms:play-services-tflite-gpu:16.1.0'
}

Enable GPU acceleration

Then initialize LiteRT with Google Play services with the GPU support:

val useGpuTask = TfLiteGpu.isGpuDelegateAvailable(context)

val interpreterTask = useGpuTask.continueWith { useGpuTask ->
  TfLite.initialize(context,
      TfLiteInitializationOptions.builder()
      .setEnableGpuDelegateSupport(useGpuTask.result)
      .build())
  }
        

Task<boolean> useGpuTask = TfLiteGpu.isGpuDelegateAvailable(context);

Task<Options> interpreterOptionsTask = useGpuTask.continueWith({ task ->
  TfLite.initialize(context,
  TfLiteInitializationOptions.builder()
    .setEnableGpuDelegateSupport(true)
    .build());
});
        

You can finally initialize the interpreter passing a GpuDelegateFactory through InterpreterApi.Options:

    val options = InterpreterApi.Options()
      .setRuntime(TfLiteRuntime.FROM_SYSTEM_ONLY)
      .addDelegateFactory(GpuDelegateFactory())

    val interpreter = InterpreterApi(model, options)

    // Run inference
    writeToInput(input)
    interpreter.run(input, output)
    readFromOutput(output)
      

    Options options = InterpreterApi.Options()
      .setRuntime(TfLiteRuntime.FROM_SYSTEM_ONLY)
      .addDelegateFactory(new GpuDelegateFactory());

    Interpreter interpreter = new InterpreterApi(model, options);

    // Run inference
    writeToInput(input);
    interpreter.run(input, output);
    readFromOutput(output);
      

The GPU delegate can also be used with ML model binding in Android Studio. For more information, see Generate model interfaces using metadata.

Use GPU with standalone LiteRT

If your application is targets devices which are not running Google Play, it is possible to bundle the GPU delegate to your application and use it with the standalone version of LiteRT.

Add project dependencies

To enable access to the GPU delegate, add com.google.ai.edge.litert:litert-gpu-delegate-plugin to your app's build.gradle file:

dependencies {
    ...
    implementation 'com.google.ai.edge.litert:litert'
    implementation 'com.google.ai.edge.litert:litert-gpu'
    implementation 'com.google.ai.edge.litert:litert-gpu-api'
}

Enable GPU acceleration

Then run LiteRT on GPU with TfLiteDelegate. In Java, you can specify the GpuDelegate through Interpreter.Options.

      import org.tensorflow.lite.Interpreter
      import org.tensorflow.lite.gpu.CompatibilityList
      import org.tensorflow.lite.gpu.GpuDelegate

      val compatList = CompatibilityList()

      val options = Interpreter.Options().apply{
          if(compatList.isDelegateSupportedOnThisDevice){
              // if the device has a supported GPU, add the GPU delegate
              val delegateOptions = compatList.bestOptionsForThisDevice
              this.addDelegate(GpuDelegate(delegateOptions))
          } else {
              // if the GPU is not supported, run on 4 threads
              this.setNumThreads(4)
          }
      }

      val interpreter = Interpreter(model, options)

      // Run inference
      writeToInput(input)
      interpreter.run(input, output)
      readFromOutput(output)
      

      import org.tensorflow.lite.Interpreter;
      import org.tensorflow.lite.gpu.CompatibilityList;
      import org.tensorflow.lite.gpu.GpuDelegate;

      // Initialize interpreter with GPU delegate
      Interpreter.Options options = new Interpreter.Options();
      CompatibilityList compatList = CompatibilityList();

      if(compatList.isDelegateSupportedOnThisDevice()){
          // if the device has a supported GPU, add the GPU delegate
          GpuDelegate.Options delegateOptions = compatList.getBestOptionsForThisDevice();
          GpuDelegate gpuDelegate = new GpuDelegate(delegateOptions);
          options.addDelegate(gpuDelegate);
      } else {
          // if the GPU is not supported, run on 4 threads
          options.setNumThreads(4);
      }

      Interpreter interpreter = new Interpreter(model, options);

      // Run inference
      writeToInput(input);
      interpreter.run(input, output);
      readFromOutput(output);
      

Quantized models

Android GPU delegate libraries support quantized models by default. You do not have to make any code changes to use quantized models with the GPU delegate. The following section explains how to disable quantized support for testing or experimental purposes.

Disable quantized model support

The following code shows how to disable support for quantized models.

GpuDelegate delegate = new GpuDelegate(new GpuDelegate.Options().setQuantizedModelsAllowed(false));

Interpreter.Options options = (new Interpreter.Options()).addDelegate(delegate);
      

For more information about running quantized models with GPU acceleration, see GPU delegate overview.