Appendix
AHD Hybrid DVR User Manual
70
Appendix B Calculate Recording Capacity
You can calculate the size of hard disk according to the storage time and AHD Hybrid DVR
recording settings. The formula is as follows in full frame rate condition. Used space per hour
(MB/h) = Bitrate (kbps) ÷ 8 × 3600 ÷ 1024. The below are the details at different settings.
Resolution
Frame Rate
Record Bitrate (kbps)
Used Space(MB/h)
720P
15 (NTSC)/
12(PAL)
6144
1350
5120
1125
4096
900
3072
675
2048
450
1024
225
The calculation format is:
Total Recording capacity = Used space per hour (MB/h) (coverage rate of hard disk) ×
recording time (hour) × channel numbers
For instance, one customer sets resolution to 720P, frame rate to 15fps, bitrate to 4M and
enables total 4 channels. He wants the unit to record continuously in a month. Below is the
calculation:
Total Recoding capacity = 225 (mb/h) × 24(hours/day) × 30(days) × 4 (channels) =
648000 (MB)
≈
633(GB)
Therefore, customers need to install 1 SATA HDD with 1TB to record for one month.
