OpenCV ANDROID_ABI: not all variants are displayed

Question

I downloaded OpenCV 2.4.13 release from GitHub. Then I configured CMake project using CMake-gui for android.

There is variable called ANDROID_ABI and I can select value for it using drop-down list. But in this list I can chose only armeabi, armeabi-v6 with VFP, armeabi-v7a, armeabi-v7a with NEON, armeabi-v7a with VFPV3.

I can use CMake console for configure and generate project for arm64 or I can modify cmake scripts and list it manually. But when I try to build generated project, I get error unknown type name '__uint128_t'__uint128_t. So I think there are reasons why I can't select this variant from drop-down list.

How can I chose arm64 variant for build and why I get such kind of error?

Answer 1

It seems that your toolchain, has no armv8 64 bit option. However there is an new opencv 3.0 release, and probably your uint errors will be fixed:

http://opencv.org/downloads.html

If your toolchain doesn't support 64 bits, you can make your own toolchain for arm64.

$NDK/build/tools/make-standalone-toolchain.sh \
--arch=arm --platform=android-21 --install-dir=/tmp/my-android-toolchain

https://developer.android.com/ndk/guides/standalone_toolchain.html?hl=es

Don't forget to put android_native_level in 21 (android 5.0.1) on cmake android options, because 64 bit support is done on devices which have android 5 or higher.