android

Android Client Library

This is the home of the android client library. It's a combination of Tensorflow C for Android, the Go client library, and an easy to use Java wrapper around them.

Get Started

Download bindable.aar and library-release.aar from the releases page and include them in your android project.

package ai.luk.example;

import ai.luk.ModelType;
import ai.luk.Tensor;
import ai.luk.DataType;

class App {
  public void train() {
    ModelType mt = new ModelType("domain", "mnist", "./mnist-files/");
    
    // Run the production model.
    feeds = new HashMap<String, Tensor>();
    feeds.put("Placeholder:0", Tensor.create(1.0f, DataType.FLOAT));
    Map<String, Tensor> outputs = mt.run(feeds, 
      Arrays.asList("Placeholder_1:0"), 
      Arrays.asList("extra inference target (optional)"));
    
    
    // Log some training examples.
    // Typically you'll pair the inputs to mt.run above with the true value and then log them. 
    // That way it creates a feedback loop to improve your model over time.
    Map<String, Tensor> feeds = new HashMap<String, Tensor>();
    feeds.put("Placeholder:0", Tensor.create(1.0f, DataType.FLOAT)); // Data type is optional
    feeds.put("Placeholder_1:0", Tensor.create(1.0f, DataType.FLOAT));
    mt.log(feeds, Arrays.asList("training_target"));


    // You will need to handle when to start and stop training. 
    // Should train when the user isn't using their phone (screen off), while charging and connected to WiFi.
    mt.startTraining();
    mt.stopTraining();
   
    // Check if there were any training or example errors.
    mt.trainingError();
    mt.examplesError();
    
    // Close the model.
    mt.close(); 
  }
}

Build from Source

Dependencies

• android-sdk (and related tools)
• android-ndk-r15c
• android-platform-21
• Bazel
• Go
• gomobile

To build you need to install android and build Tensorflow for android. You'll need to use the luk-ai/tensorflow fork and then run the commands below. Other versions of the NDK may work, but are untested.

ENV variables:

export ANDROID_HOME=/opt/android-sdk
export ANDROID_SDK=$ANDROID_HOME
export ANDROID_SDK_HOME=$ANDROID_HOME
export ANDROID_SDK_API_LEVEL=23
export ANDROID_NDK_HOME=$HOME/Developer/android-ndk-r15c
export ANDROID_NDK_API_LEVEL=23
export ANDROID_BUILD_TOOLS_VERSION=27.0.3

Run ./configure to apply those envariables. Make sure to manually configure android in case it missed anything.

Building Tensorflow for Android

Arm

sed -i 's/API_LEVEL="21"/API_LEVEL="15"/g' .tf_configure.bazelrc
bazel build --config=android_arm //tensorflow/contrib/android:libtensorflow_inference.so  --cxxopt='--std=c++11'
mkdir -p $GOPATH/pkg/gomobile/lib/arm
cp $ANDROID_NDK_HOME/platforms/android-15/arch-arm/usr/lib/* $GOPATH/pkg/gomobile/lib/arm/
cp -f bazel-bin/tensorflow/contrib/android/libtensorflow_inference.so $GOPATH/pkg/gomobile/lib/arm/libtensorflow.so

Arm64

sed -i 's/API_LEVEL="15"/API_LEVEL="21"/g' .tf_configure.bazelrc
bazel build --config=android_arm64 //tensorflow/contrib/android:libtensorflow_inference.so  --cxxopt='--std=c++11'
mkdir -p $GOPATH/pkg/gomobile/lib/arm64
cp $ANDROID_NDK_HOME/platforms/android-21/arch-arm64/usr/lib/* $GOPATH/pkg/gomobile/lib/arm64/
cp -f bazel-bin/tensorflow/contrib/android/libtensorflow_inference.so $GOPATH/pkg/gomobile/lib/arm64/libtensorflow.so

x86

sed -i 's/API_LEVEL="21"/API_LEVEL="15"/g' .tf_configure.bazelrc
bazel build --config=android //tensorflow/contrib/android:libtensorflow_inference.so  --cxxopt='--std=c++11' --cpu=x86 --fat_apk_cpu=x86
mkdir -p $GOPATH/pkg/gomobile/lib/386
cp $ANDROID_NDK_HOME/platforms/android-15/arch-x86/usr/lib/* $GOPATH/pkg/gomobile/lib/386/
cp -f bazel-bin/tensorflow/contrib/android/libtensorflow_inference.so $GOPATH/pkg/gomobile/lib/386/libtensorflow.so

x86_64

sed -i 's/API_LEVEL="15"/API_LEVEL="21"/g' .tf_configure.bazelrc
bazel build --config=android //tensorflow/contrib/android:libtensorflow_inference.so --cpu=x86_64 --fat_apk_cpu=x86_64  --cxxopt='--std=c++11'
mkdir -p $GOPATH/pkg/gomobile/lib/amd64
cp $ANDROID_NDK_HOME/platforms/android-21/arch-x86_64/usr/lib/* $GOPATH/pkg/gomobile/lib/amd64/
cp -f bazel-bin/tensorflow/contrib/android/libtensorflow_inference.so $GOPATH/pkg/gomobile/lib/amd64/libtensorflow.so

Build bindable.aar (Tensorflow + Go Client Library)

Once you've built Tensorflow for all of the various architectures you have to build the Go wrapper and package it all up into one AAR file.

cd android
make

Final AAR file will be at android/bindable/bindable.aar

Build Java client library

Once you've built bindable.aar you need to build the Java client library.

# Run tests
gradle :library:test :library:connectedDebugAndroidTest --stacktrace --info
# Build
gradle :library:assemble --stacktrace --info

Final AAR file is found at android/library/build/outputs/aar/library-release.aar you need to include this and bindable.aar in the final application.

Old way to build Tensorflow For Android

Commands to build Android dependencies:

Arm

sed -i 's/api_level=21,/api_level=15,/g' WORKSPACE
bazel build -c opt --verbose_failures //tensorflow/contrib/android:libtensorflow_inference.so --crosstool_top=//external:android/crosstool --host_crosstool_top=@bazel_tools//tools/cpp:toolchain --cpu=armeabi-v7a
mkdir -p $GOPATH/pkg/gomobile/lib/arm
cp $ANDROID_NDK_HOME/platforms/android-15/arch-arm/usr/lib/* $GOPATH/pkg/gomobile/lib/arm/
cp -f bazel-bin/tensorflow/contrib/android/libtensorflow_inference.so $GOPATH/pkg/gomobile/lib/arm/libtensorflow.so

Arm64

sed -i 's/api_level=15,/api_level=21,/g' WORKSPACE
bazel build -c opt --verbose_failures //tensorflow/contrib/android:libtensorflow_inference.so --crosstool_top=//external:android/crosstool --host_crosstool_top=@bazel_tools//tools/cpp:toolchain --cpu=arm64-v8a
mkdir -p $GOPATH/pkg/gomobile/lib/arm64
cp $ANDROID_NDK_HOME/platforms/android-21/arch-arm64/usr/lib/* $GOPATH/pkg/gomobile/lib/arm64/
cp -f bazel-bin/tensorflow/contrib/android/libtensorflow_inference.so $GOPATH/pkg/gomobile/lib/arm64/libtensorflow.so

x86

sed -i 's/api_level=21,/api_level=15,/g' WORKSPACE
bazel build -c opt --verbose_failures //tensorflow/contrib/android:libtensorflow_inference.so --crosstool_top=//external:android/crosstool --host_crosstool_top=@bazel_tools//tools/cpp:toolchain --cpu=x86
mkdir -p $GOPATH/pkg/gomobile/lib/386
cp $ANDROID_NDK_HOME/platforms/android-15/arch-x86/usr/lib/* $GOPATH/pkg/gomobile/lib/386/
cp -f bazel-bin/tensorflow/contrib/android/libtensorflow_inference.so $GOPATH/pkg/gomobile/lib/386/libtensorflow.so

x86_64

sed -i 's/api_level=15,/api_level=21,/g' WORKSPACE
bazel build -c opt --verbose_failures //tensorflow/contrib/android:libtensorflow_inference.so --crosstool_top=//external:android/crosstool --host_crosstool_top=@bazel_tools//tools/cpp:toolchain --cpu=x86_64
mkdir -p $GOPATH/pkg/gomobile/lib/amd64
cp $ANDROID_NDK_HOME/platforms/android-21/arch-x86_64/usr/lib/* $GOPATH/pkg/gomobile/lib/amd64/
cp -f bazel-bin/tensorflow/contrib/android/libtensorflow_inference.so $GOPATH/pkg/gomobile/lib/amd64/libtensorflow.so