short buf[FFT_LENGTH / PAD_FACTOR / OVERLAP];
read_chunk(fd, buf, FFT_LENGTH / PAD_FACTOR / OVERLAP);
std::pair<double, double> peak = pd.detect_pitch(buf);
short buf[FFT_LENGTH / PAD_FACTOR / OVERLAP];
read_chunk(fd, buf, FFT_LENGTH / PAD_FACTOR / OVERLAP);
std::pair<double, double> peak = pd.detect_pitch(buf);