537: interframe interval = 1/27.31 s  avg=1/27.90  stddev=1/68.05
  525: interframe interval = 1/30.18 s  avg=1/28.15  stddev=1/82.06
  525: interframe interval = 1/35.87 s  avg=1/27.84  stddev=1/62.80
  538: interframe interval = 1/33.25 s  avg=1/26.63  stddev=1/59.73
  537: interframe interval = 1/28.88 s  avg=1/27.74  stddev=1/69.32
  526: interframe interval = 1/ 6.05 s  avg=1/27.95  stddev=1/69.62