if (sf_seek (sf, (sf_count_t) start, SEEK_SET|SFM_READ) != (sf_count_t) start) {
char errbuf[256];
sf_error_str (0, errbuf, sizeof (errbuf) - 1);
if (sf_seek (sf, (sf_count_t) start, SEEK_SET|SFM_READ) != (sf_count_t) start) {
char errbuf[256];
sf_error_str (0, errbuf, sizeof (errbuf) - 1);