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APPENDIX A: HARD DISK CAPACITY CALCULATION
Calculate total capacity needed by each NVR 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 , 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 NVR during scheduled video recording.
�
=
=
c
i
i
T
m
q
1
(3)
In the formula: c means total number of channels in one NVR
Step 4: According to Formula (4) to calculate total capacity (accumulation)
T
q
that is needed for all channels in NVR during alarm video recording (including
motion detection).
�
=
=
c
i
i
T
m
q
1
×a% (4)
In the formula: a% means alarm occurrence rate
