CopyTo loding data

edit

I've stepped through the code, through each OpenCV 3.4.0 function, and I just can't understand why data is being lost or destroyed on my faster systems.

When I use CMat::copyTo to send data to a CMat that has already had its frame buffer allocated (I checked, 8MB allocated), and the scope of the receiving CMat is always in range, why should there be a memory problem?

Using clone solves the problem but allocates memory again for the receiving CMat.

CopyTo just memcpy's to the target CMat's data, so it should work. I stepped through the destructors in my copy procedure, and the target CMat receiving the data is not freed.

If I call ShowImg() on the returned data after the copy call, then the memory problem goes away.

Appreciate any advice on this.

My test code to copy a D3D9 surface to a OpenCV CMat:-

void main()
{
while (input() != _ESC)
{
    if (!m_pInputLeft)
    {
        m_pInputLeftRight = new cv::Mat(pSBM->pTexture->getSize().Height, pSBM->pTexture->getSize().Width, CV_8UC4);
        // I stepped thro and memory gets allocated, some 8 MBS for an FHD sized frame
    }

    // *** Copy video frame (DShow RGBA) that was input to OpenCV BGR to LR Mat
    if (CopyTextureToMat(pSBM->pTexture, m_pInputLeftRight), 1)
    {
        DisplayFrame(m_pInputLeftRight);    // Frame data does not get displayed if copy mode is copyTo (clone works!)
    }
}
}


bool CopyTextureToMat(CD3D9Texture *pD9Tex , cv::Mat *pDest, SBM_P *pParams)
{
    IDirect3DSurface9 *pSurf;
    if (!pD9Tex || !pDest)
        return false;
    HRESULT r = pD9Tex->Texture->GetSurfaceLevel(0, &pSurf);    // Get DX9 surface from Viva3D texture
    if (r != S_OK)
        return false;
    r = pSurf->LockRect(&memDesc, NULL, D3DLOCK_READONLY | D3DLOCK_NO_DIRTY_UPDATE);    // D3DLOCK_READONLY
    if (FAILED(r))
    {
        if (r == D3DERR_WASSTILLDRAWING)
        {
            bool b = true;  // Debug point only
        }
        else
        if (r == D3DERR_INVALIDCALL)
        {
            bool b = true;
        }
        return false;
    }

    pMatOut = new cv::Mat(iHeight, iWidth, CV_8UC4, memDesc.pBits, memDesc.Pitch);  // Create Mat using same memory as DX9 surface

    static bool bCopyMode = 0;

    if (bCopyMode)
        pMatOut->copyTo(*pDest);    // On higher speed systems the memory is being destroyed (no exception occurs on use though)
    else
    {
        *pDest = pMatOut->clone();  // This duplicates the data and works on the higher speed systems
    }

    r = pSurf->UnlockRect();

    delete pMatOut;

    if (FAILED(r))
        return false;
    return true;
}