MAX_DURATION       59 libavfilter/af_silencedetect.c     { "d",         "set minimum duration in seconds",  OFFSET(duration),  AV_OPT_TYPE_DURATION, {.i64=2000000},      0, MAX_DURATION,FLAGS },
MAX_DURATION       60 libavfilter/af_silencedetect.c     { "duration",  "set minimum duration in seconds",  OFFSET(duration),  AV_OPT_TYPE_DURATION, {.i64=2000000},      0, MAX_DURATION,FLAGS },