custom_rules.xml

<?xml version="1.0" encoding="UTF-8"?>
<project name="pulse-android-custom-rules">

  <!-- quick check on ndk.dir -->
  <fail
          message="ndk.dir is missing in your local.properties file."
          unless="ndk.dir"
  />
  <!-- quick check on pulse-cpp.dir -->
  <fail
          message="pulse-cpp.dir is missing in your local.properties file."
          unless="pulse-cpp.dir"
  />

  <target name="-pre-build">

    <!-- rsync pulse-android-cpp files to jni folder -->
    <exec executable="rsync">
      <arg value="-au"/>
      <!-- src -->
      <arg value="${pulse-cpp.dir}/src/Pulse.hpp"/>
      <arg value="${pulse-cpp.dir}/src/Pulse.cpp"/>
      <arg value="${pulse-cpp.dir}/src/EvmGdownIIR.hpp"/>
      <arg value="${pulse-cpp.dir}/src/EvmGdownIIR.cpp"/>
      <arg value="${pulse-cpp.dir}/src/ext"/>
      <arg value="${pulse-cpp.dir}/src/profiler"/>
      <!-- dst -->
      <arg value="jni"/>
    </exec>

    <!-- android ndk-build jni files -->
    <exec executable="${ndk.dir}/ndk-build" failonerror="true"/>

  </target>

  <target name="-pre-clean">

    <!-- android ndk-build clean jni files -->
    <exec executable="${ndk.dir}/ndk-build">
      <arg value="clean"/>
    </exec>

  </target>

</project>