secid              82 ext/fileinfo/libmagic/cdf.h #define CDF_SEC_POS(h, secid) (CDF_SEC_SIZE(h) + (secid) * CDF_SEC_SIZE(h))
secid              84 ext/fileinfo/libmagic/cdf.h #define CDF_SHORT_SEC_POS(h, secid) ((secid) * CDF_SHORT_SEC_SIZE(h))