JavaCameraView delivers same frame twice (Bug #3123)

I created an android application based on difference image. Every secound difference frame has no difference. Finnally i found a problem in JavaCameraView class.

In method initialzeCamera() the JavaCameraFrame class will be instantiated:
mCameraFrame = new JavaCameraFrame(mFrameChain[mChainIdx], mFrameWidth, mFrameHeight);

this object will now always use the Mat from mChanIdx 0.

In CameraWorker Thread the deliverAndDrawFrame method alaways gets the mat stored in mFrameChain index 0 because mCameraFrame gets no update about the new frame if mChainIdx has value 1.
if (!mStopThread) {
if (!mFrameChain[mChainIdx].empty())
deliverAndDrawFrame(mCameraFrame);
mChainIdx = 1 - mChainIdx;
}

We propose to update the mCameraFrame object with the current Mat in the onPreviewFrame method.

Thank you!