IP and digital CCTV offer a number of options when considering the recording of images.
These would include the use of hybrid digital video recorders (DVRs), network video recorders (NVRs), server based storage utilising specialist VMS software and recording in the camera itself (known as recording at the edge).
- Hybrid Digital Recorder (DVR) – Excellent for low cost system that allows the migration from existing analogue technology to IP and megapixel cameras. This is capable of recording and displaying all types of cameras.
- Network Video Recorder (NVR) - Typically dedicated to allow the recording of IP and megapixel cameras using specialist software residing on storage systems specifically designed for the purpose. The NVR can record analogue cameras using separate video encoders.
- Server based enterprise storage system with VMS Software - Can be based a centralised server or SAN based systems and shared with other corporate storage applications. Sophisticated video management software (VMS) provides detailed management of the storage and display process with full audit trail. The use of commoditised hardware reduces capital and operating costs.
- Edge recording - The reduction in the relative cost of flash memory provides opportunities to place substantial recording capacity inside each camera. This can offer advantages in terms of significant reduction in network utilisation and capacity. Some management systems allow for background recording and alarm events to be captured by the on-board memory, in addition to alarm events only being transmitted to the central monitoring location.
Even though the cost of storage continues to fall, advances in megapixel camera technology place increasing demands on both the supporting transmission infrastructure and storage system.
Implementation of a recording strategy requires consideration of many key elements that should result from the analysis of the operational requirement, which in turn offer guidance for system configuration of key elements such as:-
- Frame rate
- Bit rate
- Encoding format (H.264, MPEG, MJPEG etc)
- Single, dual or multiple streaming
- Analytics - including automatic number plate recognition (known as ANPR or LPR), Face recognition, tripwire, left or missing article, camera masking, defocus alarm, people counting etc
- Evidence Download – single incident and bulk download
- Audit trail
- System scalability – including increases in camera numbers, integration with Physical Security Information Management (PSIM including Fire Alarm Access Control, Intruder Alarm, Building Management systems(BMS), Lift alarms/help points etc) and anticipating future technologies that may be available within the life of the system installed
- Time synchronisation
- System security
|Click here to contact us|