54
Appendix B
Calculate Recording Capacity
Users can calculate the size of hard disk according to the saving time and DVR recording settings. The DVR
uses fixed video bit rate. The below are the details at different settings.
Video
Format
Resolution
Frame Rate
Totally(FPS)
Video Quality
Bit Rate
(kbps)
Used
Space(MB/h)
NTSC
CIF
30
Highest
1M
465
Higher
768k
297
Medium
512k
230
Low
384k
173
Lower
256k
115
Lowest
128k
56
PAL
CIF
25
Highest
1M
466
Higher
768k
295
Medium
512k
235
Low
384k
175
Lower
256k
56.4
Lowest
128k
45
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 uses PAL cameras, set resolution to CIF, video quality to Lower, frame rate to 25
fps for enabling total 16 channels. He wants the unit to record continuously in a month. Below is the
calculation:
Total Recoding capacity =56.4 (mb/h) X 24(hours/day) X30(days) X16(channels)= 649728(MB)
≈
650(GB)
Therefore, customers just install two SATA HDDs with 320GB, it can almost record for one month.
