Dahua HCVR21**HS-S2 Series, User Manual

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HDCVI Series DVR User
’s Manual
311
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
   
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