Appendix 2 Hdd Capacity Calculation - Dahua DH-XVR4104C-X User Manual

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
channel needed for each hour, unit MB.
In the formula:
Step 2 After video time requirement is confirmed, according to Formula (2) to calculate the
storage capacity
In the formula:
h
means the recording time for each day (hour)

i
D
means number of days for which the video shall be kept

i
Step 3 According to Formula (3) to calculate total capacity (accumulation)
for all channels in the DVR during scheduled video recording.
In the formula:
Step 4 According to Formula (4) to calculate total capacity (accumulation)
for all channels in DVR during alarm video recording (including motion detection).
In the formula：a% means alarm occurrence rate
You can refer to the following table for the file size in one hour per channel. (All the data listed
below are for reference only.)
Bit stream size（max） File size
96Kbps
160Kbps
224Kbps
320Kbps
448Kbps
Appendix 2
Formula (1):
d
means the bit rate, unit Kbit/s
i
m
, which is storage of each channel needed unit MB.
i
Formula (2):
Formula (3):
c
means total number of channels in one DVR
Formula (4):
Bit stream size（max） File size
42MB 128Kbps
70MB 192Kbps
98MB 256Kbps
140MB 384Kbps
196MB 512Kbps
HDD Capacity Calculation
q
that is the capacity of each
i
   
q d 8 3600 1024
i i
h D
m q
= × ×
i i
i i
c


q m
T i

i 1
c


q m
×a%
T i

i 1
HDD Capacity Calculation 296
q
that is needed
T
q
that is needed
T
56MB
84MB
112MB
168MB
225MB