flac_parse_block_header(buf, &metadata_last, NULL, &metadata_size);
buf += 4;
if (buf_end - buf < metadata_size) {
/* need more data in order to read the complete header */
flac_parse_block_header(buf, &metadata_last, NULL, &metadata_size);
buf += 4;
if (buf_end - buf < metadata_size) {
/* need more data in order to read the complete header */