void Window::fft(float* correction){
    m_fft_data = (float*) av_malloc(sizeof(float)*Globals::WindowSize);
    memcpy(m_fft_data, correction, sizeof(float)*Globals::WindowSize);
    for(int i = 0; i < Globals::WindowSize; ++i){
            m_fft_data[i] *= m_data[i];
    }

    RDFTContext * ctx = av_rdft_init(Globals::WindowSizePower, DFT_R2C);
    av_rdft_calc(ctx, m_fft_data);
    av_rdft_end(ctx);

    for(int i = 0; i < Globals::WindowFFTBins; ++i){
        m_fft_data[i] =
            powf(m_fft_data[i],2) +
            powf(m_fft_data[Globals::WindowSize - i],2);
    }
}