void FFTLib::Compute(FFTFrame &frame) {
kiss_fftr(m_cfg, m_input, m_output);
auto input = m_output;
auto output = frame.data();
for (size_t i = 0; i <= m_frame_size / 2; ++i, ++input, ++output) {
*output = input->r * input->r + input->i * input->i;
}
}
void FFTLib::Compute(FFTFrame &frame) {
fftw_execute(m_plan);
auto output = frame.data();
auto in_ptr = m_output;
auto rev_in_ptr = m_output + m_frame_size - 1;
output[0] = in_ptr[0] * in_ptr[0];
output[m_frame_size / 2] = in_ptr[m_frame_size / 2] * in_ptr[m_frame_size / 2];
in_ptr += 1;
output += 1;
for (size_t i = 1; i < m_frame_size / 2; i++) {
*output++ = in_ptr[0] * in_ptr[0] + rev_in_ptr[0] * rev_in_ptr[0];
in_ptr++;
rev_in_ptr--;
}
}