bcf1_t

The bcf1_t structure corresponds to one VCF/BCF line. Reading from VCF file is slower because the string is first to be parsed, packed into BCF line (done in vcf_parse), then unpacked into internal bcf1_t structure. If it is known in advance that some of the fields will not be required (notably the sample columns), parsing of these can be skipped by setting max_unpack appropriately. Similarly, it is fast to output a BCF line because the columns (kept in shared.s, indiv.s, etc.) are written directly by bcf_write, whereas a VCF line must be formatted in vcf_format.