for (unsigned i = 0; i < total_end; ++i) {
double d = lanczos_interpolate(best_path, i / double(BUFSIZE));
int left = pcm[i].left;
int right = lanczos_interpolate_right(pcm, i + d);
for (unsigned i = 0; i < total_end; ++i) {
double d = lanczos_interpolate(best_path, i / double(BUFSIZE));
int left = pcm[i].left;
int right = lanczos_interpolate_right(pcm, i + d);