Siera SDR 2004 - Appendix A Hdd Capacity Calculation

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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.
102436008
÷
×
÷
=
ii
dq
(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
iT
mq
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
iT
mq
1
×a% (4)
In the formula：a% means alarm occurrence rate