xanderkoo / mediapipe

Forked repo for building AAR for MediaPipe hand tracking in Unity

MediaPipe AAR Build Guide (For Mac/Linux)

This repo is meant to be a guide for building an MediaPipe plugin for Android, specifically to be used in Unity. This example uses Hand Tracking, but other dependencies can probably also be subbed in easily. Please reference this official guide for more info.

Note: I haven't verified that this works with Linux.

1. Install Bazel

2. Clone or download copy of this repo or https://github.com/google/mediapipe

   • If you clone this repo, skip to Step 6

3. Run the following:

   mkdir ./mediapipe/examples/android/src/java/com/google/mediapipe/apps/aarhandtracking
   touch ./mediapipe/examples/android/src/java/com/google/mediapipe/apps/aarhandtracking/BUILD
   

4. Add following to the new BUILD file:

   load("//mediapipe/java/com/google/mediapipe:mediapipe_aar.bzl", "mediapipe_aar")
   
   mediapipe_aar(
       name = "mp_hand_tracking_aar",
       calculators = ["//mediapipe/graphs/hand_tracking:mobile_calculators"],
   )
   

5. Add the following snippet to ./mediapipe/java/com/google/mediapipe/mediapipe_aar.bzl

   def mediapipe_aar(name, calculators = [], assets = [], assets_dir = ""):
   
         ...
   
         _proto_java_src_generator(
               name = "rect_proto",
               proto_src = "mediapipe/framework/rect.proto",
               java_lite_out = "com/google/mediapipe/formats/proto/RectProto.java",
               srcs = ["//mediapipe/framework/formats:protos_src"],
         )
   
         ...
   

6. Run the following to prepare our directories (you can delete these after you're done):

   export SDK_PATH="${HOME}/android/sdk"
   export NDK_PATH="${HOME}/android/ndk"
   mkdir -p "${SDK_PATH}"
   mkdir -p "${NDK_PATH}"
   

7. Install SDK and NDK:

   • Go here to find the latest command line tools, and copy the link to the latest download, e.g. https://dl.google.com/android/repository/commandlinetools-mac-6858069_latest.zip

     export SDK_DOWNLOAD_URL="{put url here}"
     

   • Go here to find the latest NDK download, and copy the link to the latest download, e.g. https://dl.google.com/android/repository/android-ndk-r21d-darwin-x86_64.zip

     export NDK_DOWNLOAD_URL="{put url here}"
     

   • Copy the Latest Stable Version id, e.g. r21d

     export NDK_VERSION="{put version number here}"
     

8. Now install the NDK and SDK with the script:

   bash ./setup_android_sdk_and_ndk_modified.sh "${SDK_PATH}" "${NDK_PATH}" "${NDK_VERSION}" "${SDK_DOWNLOAD_URL}" "${NDK_DOWNLOAD_URL}"
   

9. Run the following:

   export ANDROID_HOME="${SDK_PATH}"
   export ANDROID_NDK_HOME="${NDK_PATH}/android-ndk-${NDK_VERSION}"
   brew install opencv3
   brew install opencv@3
   

10. Run the Bazel build command as such:

    bazel build -c opt --host_crosstool_top=@bazel_tools//tools/cpp:toolchain --fat_apk_cpu=arm64-v8a,armeabi-v7a //mediapipe/examples/android/src/java/com/google/mediapipe/apps/aarhandtracking:mp_hand_tracking_aar
    

AAR file should build to ./bazel-bin/mediapipe/examples/android/src/java/com/google/mediapipe/apps/aarhandtracking