stores Number:20, var:4, Type:4, ColType:4 in info[0..2] for BCF_HL_FLT,INFO,FMT and contig length in info[0] for BCF_HL_CTG
See Implementation
stores Number:20, var:4, Type:4, ColType:4 in info[0..2] for BCF_HL_FLT,INFO,FMT and contig length in info[0] for BCF_HL_CTG