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Appendix B 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 every 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
