android: build package with API 21

enables Video I/O backend via Media NDK

platforms/android/build-tests/test_cmake_build.py

@@ -112,10 +112,10 @@ class TestCmakeBuild(unittest.TestCase):
 
 def suite(workdir, opencv_cmake_path):
     abis = {
-        "armeabi-v7a": { "ANDROID_ABI": "armeabi-v7a", "ANDROID_TOOLCHAIN": "clang", "ANDROID_STL": "c++_static" },
+        "armeabi-v7a": { "ANDROID_ABI": "armeabi-v7a", "ANDROID_TOOLCHAIN": "clang", "ANDROID_STL": "c++_static", 'ANDROID_NATIVE_API_LEVEL': "21" },
-        "arm64-v8a": { "ANDROID_ABI": "arm64-v8a", "ANDROID_TOOLCHAIN": "clang", "ANDROID_STL": "c++_static" },
+        "arm64-v8a": { "ANDROID_ABI": "arm64-v8a", "ANDROID_TOOLCHAIN": "clang", "ANDROID_STL": "c++_static", 'ANDROID_NATIVE_API_LEVEL': "21" },
-        "x86": { "ANDROID_ABI": "x86", "ANDROID_TOOLCHAIN": "clang", "ANDROID_STL": "c++_static" },
+        "x86": { "ANDROID_ABI": "x86", "ANDROID_TOOLCHAIN": "clang", "ANDROID_STL": "c++_static", 'ANDROID_NATIVE_API_LEVEL': "21" },
-        "x86_64": { "ANDROID_ABI": "x86_64", "ANDROID_TOOLCHAIN": "clang", "ANDROID_STL": "c++_static" },
+        "x86_64": { "ANDROID_ABI": "x86_64", "ANDROID_TOOLCHAIN": "clang", "ANDROID_STL": "c++_static", 'ANDROID_NATIVE_API_LEVEL': "21" },
     }
 
     suite = unittest.TestSuite()

platforms/android/build_sdk.py

@@ -281,7 +281,7 @@ if __name__ == "__main__":
     parser = argparse.ArgumentParser(description='Build OpenCV for Android SDK')
     parser.add_argument("work_dir", nargs='?', default='.', help="Working directory (and output)")
     parser.add_argument("opencv_dir", nargs='?', default=os.path.join(SCRIPT_DIR, '../..'), help="Path to OpenCV source dir")
-    parser.add_argument('--config', default='ndk-18.config.py', type=str, help="Package build configuration", )
+    parser.add_argument('--config', default='ndk-18-api-level-21.config.py', type=str, help="Package build configuration", )
     parser.add_argument('--ndk_path', help="Path to Android NDK to use for build")
     parser.add_argument('--sdk_path', help="Path to Android SDK to use for build")
     parser.add_argument('--use_android_buildtools', action="store_true", help='Use cmake/ninja build tools from Android SDK')