21 And later Zechariah son of Meshelemiah
had been responsible for guarding the entrance of the
tabernacle.
22 In all, there were 212 gatekeepers in those days, and
they were listed by genealogies in their villages.
David and Samuel the seer had appointed their ancestors
because they were reliable men.
23 These gatekeepers and their descendants, by their
divisions, were responsible for guarding the entrance to the
house of the LORD, the house that was formerly a tent.
24 The gatekeepers were stationed on all four sides—east,
west, north, and south.
DVR Testing
We see various claims of frame rates
at high resolution, storage capacities, etc. What the DVR is actually
capable of might be quite different. We first experienced this when testing IP
based solutions. Systems touting 15 frames a second were actually only capable
of 7.5, etc.
We believe that this testing method
levels the playing field across the board. The test tortures the DVR by feeding
every channel with full time activity. Part of the screen is running a Timer
flash so that you can actually see how many frames a second a DVR is capturing
when playing back the recorded frames.
Objective: Test a DVR for maximum
frame rates at maximum resolution to see if the DVR can live up to it's
specifications.
Result: Bring a DVR to it's knees
begging for mercy.
Here's how?
You will need the following-
A PC that can play media clips
for about a week solid. - This test will tie up a PC for about a week.
DVR to be tested - 16 channel
High Resolution color camera and
power supply
Flash Timer software
Looping cables and connectors.
The DVR should have all channels set
to the maximum frame rate and resolution.
Also set each for motion detection
recording only. Set a 5 second pre and post event recording.
Select a video clip that has lots of
action on most of the screen. We used a clip of 911 events that had constant
motion over most of the screen.
Bring up the video clip on media
player and set it to continuous loop (keep repeating over and over). Full screen
display
Start the Flash Timer at the bottom
of the PC screen.
The wiring loop is made to loop feed
the same picture to all 16 channels.
The result is the DVR that looks
like this when in operation.
Run this test until all available
storage is used up and the DVR starts re-recording over old data. This should
take about a week with a terabyte of hard disk.
Now sample the recording from
the beginning of it's storage and the end. Check to see how many actual frames
per second is recorded by watching the timer and forwarding frame by frame until
you see the second digit in the timer change. Presto, that is how many actual
frames you are getting.
We have tested various DVR. Some are
great and some total failures. We even toasted one DVR to where it lost all
recording and started from scratch (not a good thing).
