opencv - Gradle android build for different processor architectures

Question

I want to build 4 separate apks for 4 different Android CPU processor architectures (armeabi armeabi-v7a x86 mips) using Gradle.

I have native OpenCV libraries built for 4 CPU architectures in the libs folder.

libs
    -armeabi
    -armeabi-v7a
    -x86
    -mips

I want to each apk only contains the OpenCV library corresponding to the correct CPU architecture.

The current build script is as below:

apply plugin: 'android'

dependencies {
    compile fileTree(dir: 'libs', include: '*.jar')
    compile project(':workspace:OpenCV4Android:sdk:java')
}

android {
    compileSdkVersion 11
    buildToolsVersion "18.1.0"

    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            aidl.srcDirs = ['src']
            renderscript.srcDirs = ['src']
            res.srcDirs = ['res']
            assets.srcDirs = ['assets']
        }

        // Move the tests to tests/java, tests/res, etc...
        instrumentTest.setRoot('tests')

        debug.setRoot('build-types/debug')
        release.setRoot('build-types/release')

        flavorGroups "abi", "version"
        productFlavors {
            x86 {
                flavorGroup "abi"
            }
            arm {
                flavorGroup "abi"
            }
            mips {
                flavorGroup "abi"
            }
        }

    }
}

Can someone help me to resolve this please?

Cheers,

Answer 1

As of Android Gradle Plugin version 13 you can now generate seperate APK's using the new "split" mechanism. You can read about it here.

The default file structure for placing your .so files is:

src
-main
  -jniLibs
    -armeabi
      -arm.so
    -armeabi-v7a
      -armv7.so
    -x86
      -x86.so
    -mips
      -mips.so

Note that the name of the .so file is unimportant as long as it has the .so extension.

Then in your Gradle build file:

android {
...
splits {
abi {
  enable true
  reset()
  include 'x86', 'armeabi-v7a', 'mips', 'armeabi'
  universalApk false
  }
 }
}

and

// map for the version code
ext.versionCodes = ['armeabi-v7a':1, mips:2, x86:3]

import com.android.build.OutputFile

android.applicationVariants.all { variant ->
    // assign different version code for each output
    variant.outputs.each { output ->
        output.versionCodeOverride =
            project.ext.versionCodes.get(output.getFilter(OutputFile.ABI)) * 1000000 + android.defaultConfig.versionCode
    }
}

Note that the version codes above in ext.versionCodes are largely irrelevant, this is here to add a unique offset for each ABI type so version codes do not clash.