139Appendix A HDD Capacity CalculationCalculate total capacity needed by each DVR according to video recording (video recording typeand video file storage time).Step 1: According to Formula (1) to calculate storage capacity iq that is the capacity of eachchannel needed for each hour, unit Mbyte.102436008 ÷×÷= ii dq (1)In the formula: id means the bit rate, unit Kbit/sStep 2: After video time requirement is confirmed, according to Formula (2) to calculate thestorage capacity im , which is storage of each channel needed unit Mbyte.im = iq × ih × iD (2)In the formula:ih means the recording time for each day (hour)iD means number of days for which the video shall be keptStep 3: According to Formula (3) to calculate total capacity (accumulation) Tq that is needed forall channels in the DVR during scheduled video recording.∑==ciiT mq 1(3)In the formula: c means total number of channels in one DVRStep 4: According to Formula (4) to calculate total capacity (accumulation) Tq that is needed forall channels in DVR during alarm video recording (including motion detection).∑==ciiT mq 1×a% (4)In the formula：a% means alarm occurrence rate
