197Appendix A HDD Capacity CalculationCalculate total capacity needed by each DVR according to video recording (videorecording type and video file storage time).Step 1: According to Formula (1) to calculate storage capacityiq that is the capacity ofeach channel needed for each hour, unit M byte.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 calculatethe storage capacityim , which is storage of each channel needed unit Mbyte.im=iq ×ih ×iD (2)In the formula:ihmeans the recording time for each day (hour)iDmeans number of days for which the video shall bekeptStep 3: According to Formula (3) to calculate total capacity (accumulation)Tq that isneeded for all 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 isneeded for all channels in DVR during alarm video recording (including motiondetection).ciiT mq 1×a% (4)In the formula:a% means alarm occurrence rateYou can refer to the following sheet for the file size in one hour per channel. (All the datalisted below are for reference only.)Bit stream size(max) File size Bit stream size(max) File size96K 42M 128K 56M160K 70M 192K 84M224K 98M 256K 112M320K 140M 384K 168M