build_with_ndk.md

Build with NDK for android

1. setup ndk
   • download and unzip android ndk package (we have tested with ndk v22b)
   • set 'export ANDROID_NDK_HOME=Your NDK root dir' to your .bashrc or .zshrc
2. cross-build
   • generate protobuf cpp files with your host profile(Linux, Mac or Windows)
   • cp mediapipe/framework/stream_handler/default_input_stream_handler.pb.cc test_package
   • conan create . -pr docker/ndk_profile --build=missing
3. test
   • copy the generated 'example' file in test_package to you android deivce's '/data/local/tmp'
   • just run it and the results will be like bellow:

   c2q:/data/local/tmp $ ./example                                                
   I20230831 13:39:44.527252 16470 example.cc:39] node {
   calculator: "SquareIntCalculator"
   input_stream: "in"
   output_stream: "out"
   }
   input_stream: "in"
   output_stream: "out"
   I20230831 13:39:44.532116 16470 example.cc:55] 0
   I20230831 13:39:44.532189 16470 example.cc:55] 1
   I20230831 13:39:44.532212 16470 example.cc:55] 4
   I20230831 13:39:44.532227 16470 example.cc:55] 9
   I20230831 13:39:44.532239 16470 example.cc:55] 16
   I20230831 13:39:44.532253 16470 example.cc:55] 25
   I20230831 13:39:44.532266 16470 example.cc:55] 36
   I20230831 13:39:44.532279 16470 example.cc:55] 49
   I20230831 13:39:44.532290 16470 example.cc:55] 64
   I20230831 13:39:44.532302 16470 example.cc:55] 81