IC Realtime Specialty: Interrogator DVR - a DVR for law enforcement - Manual (Page 131)

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Appendix A HDD Capacity Calculation
Calculate total capacity needed by each DVR according to video recording (video
recording type and video file storage time).
Step 1: According to Formula (1) to calculate storage capacity
i
q that is the capacity of
each channel needed for each hour, unit Mbyte.
1024 3600 8 ч Ч ч =
i i
d q
(1)
In the formula:
i
d means the bit rate, unit Kbit/s
Step 2: After video time requirement is confirmed, according to Formula (2) to calculate
the storage capacity
i
m , which is storage of each channel needed unit Mbyte.
i
m =
i
q ×
i
h ×
i
D (2)
In the formula:
i
h means the recording time for each day (hour)
i
D means number of days for which the video shall be
kept
Step 3: According to Formula (3) to calculate total capacity (accumulation)
T
q
that is
needed for all channels in the DVR during scheduled video recording.
∑
=
=
c
i
i T
m q
1
(3)
In the formula:
c
means total number of channels in one DVR
Step 4: According to Formula (4) to calculate total capacity (accumulation)
T
q
that is
needed for all channels in DVR during alarm video recording (including motion
detection)
.
∑
=
=
c
i
i T
m q
1
×a% (4)
In the formula：a% means alarm occurrence rate