msec_ratio       1266 src/libsir/src/sirinternal.c     double msec_ratio = ((double)_sir_perfcntr_freq.QuadPart) / 1e3;
msec_ratio       1267 src/libsir/src/sirinternal.c     return ((double)(out->counter.QuadPart - when->counter.QuadPart)) / msec_ratio;