The subdirectory used for this example cointains around 3300 BMP filesas expected, as considering that the alarm time window is 11 seconds and the frame rate is 300fps:
<pre class="board-terminal">
sysadmin@hfrcpoc1-0:/mnt/alarms/2020-08-06_10.30.08_CEST$ ls *.bmp | wc -l