Methods Of Calculating Hdd Capacity - Kogan KACCTV4CHA User Manual

2 Methods of Calculating HDD Capacity

1) Calculate the maximum capacity of the built-in hard disk.
Timing Recording:
Step 1: Calculate the maximum capacity of the hard disk needed in selected channel per hour, which
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we will classify as Si(MByte) with i representing the channel number. With the bit rate of the channel
being classified as D (Kbit/s), the formula is as follows:
Si = (Dx3600) / (8x1024) = D x 0.439453125 MB
Step 2: Confirm the storage length time, which we will classify as T hours. The total maximum
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capacity of the hard disk needed in the selected channel for T hours is:
St = T x S1
Step 3: Confirm the total numbers of the channels, set here as n. The total maxmimum capacity of
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the hard disk needed, represented as Sc below is:
Sc = S1 + S2 + ... + Sn
Alarm Recording:
Suppose the rate of alarm is a%. The capacity of the hard disk needed in alarm recording (classified
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here as Sa) is:
Sa = Sc x a%
2) Calculate the compression bit rate for recording T hours.
*Timing Recording
Step 1: Support the capacity of the hard disk is S and the total numbers of channels is n. The
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capacity of the hard disk needed per channel (known as Di) is:
Di = S / n
Step 2: Support the total recording time is T. The capacity of the hard disk needed per hour per
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channel (known as Dt) is:
Dt = Di / T
Step 3: The bit rate of all the channels (known as Dc) is:
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Dc = Dt x (8 x 1024) / 3600 = Dt x 2.2756 (Kbit/s)
*Alarm Recording
Step 1: The rate of alarm (known as a%), the capacity of the hard disk as S and the total numbers of the
channel as n. The capacity of the hard disk needed per channel is Di:
Di = (S/n) x a%
Step 2: With the time length of the recording (known as T (hours)), the capacity of the hard disk needed per
hour per channel (known as Dt) is:
Dt = Di / T
Step 3: The bit rate of all channels (known as Dc) is:
Dc = Dt x (8x1024) / 3600 = Dt x 2.2756 (Kbit/s)
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