System information (version)

• OpenCV => 3.4.1
• Operating System macOS High Sierra 10.13.6 / Platform => Android 7.1.1 API 25
• Compiler => Android NDK

Detailed description

Context

I'm writing a cross platform OpenCV based C++ library. The consuming code is a React Native Application through a react native native module.

To be perfectly clear, there is no access from Java Code to C++ OpenCV on Android. There are events with the result of the OpenCV C++ code sent to Javascript through the react native bridge.

My native library is compiled on Android as a SHARED library. It is dynamically linked to the libopencv_world.so that is produced by the compilation of OpenCV C++ for Android.

What it does

Basically, it opens the device's default camera and take snapshots.

The outcome

This code is then ran on iOS and Android.

This is working perfectly well on iOS.
It fails on Android.

Here is the failing part of C++ code on Adndroid:

Steps to reproduce

// cap is a cv::VideoCapture object    
if (cap.open(0))
        {
            cap.set(cv::CAP_PROP_FRAME_WIDTH, CAM_WIDTH);
            cap.set(cv::CAP_PROP_FRAME_HEIGHT, CAM_HEIGHT);
        }
        else
        {
            reject("false", "cap.open(0) returned false");
        }