Characteristics of Video Recorders for Surveillance Systems: What to Look For

Characteristics of Video Recorders for Surveillance Systems

Video recorders are categorized into three main types, depending on the video signal processing method:

• DVR (Digital Video Recorder):

  • Designed for analog surveillance cameras.
  • Converts analog signals to digital format.
  • Commonly referred to as "analog" due to the type of cameras it supports.

• NVR (Network Video Recorder):

  • Designed for IP cameras.
  • Utilizes Ethernet networks for data transmission.
  • Often supports PoE (Power over Ethernet) technology for simultaneous power and data transfer.

• HVR (Hybrid Video Recorder):

  • Compatible with both analog and IP cameras.
  • Ideal for hybrid surveillance systems.

Key Features:

1. Number of Recording Channels:

   • Small to medium-sized systems typically use 4, 8, or 16-channel models.
   • 32-channel models are available for larger systems but come with a significantly higher price tag.

2. Resolution and Frame Rate:

   • Standard resolutions: HD (1280x720) and Full HD (1920x1080).
   • Basic security systems often use D1 (704x576) or CIF (352x288).
   • Optimal frame rate: 25 fps (frames per second) for smooth video playback.

3. Video Compression Format:

   • H.264: The most efficient and widely used format, providing high-quality compression.
   • MPEG4: Less efficient and requires more storage space.
   • MJPEG: Outdated format and not recommended.

4. Data Storage:

   • Hard drives (HDDs) are usually sold separately.
   • Recommended: Western Digital (WD Purple, SE, or RE series) or Seagate Surveillance HDD models.
   • For added reliability, RAID configurations (e.g., RAID 1 or 5) are recommended to safeguard data.

5. Additional Ports and Connectivity:

   • VGA/HDMI for monitor connections.
   • RS-485 for PTZ (Pan-Tilt-Zoom) camera control.
   • RJ-45 for network integration, USB for archiving and configuration.
   • Audio inputs/outputs for microphones and speakers.

6. Software Capabilities:

   • Most systems run on Linux OS.
   • Features include remote management, archive search by date/time, and multi-recorder integration.
   • Advanced features: motion detection, sound-based recording, and electronic maps for surveillance zones.

Characteristics of Automotive Dash Cameras

Automotive dash cameras are essential for road safety. When choosing a device, consider the following features:

1. Resolution and Recording Speed:

   • Minimum resolution: 1280x720 (HD).
   • Recording speed: 25-30 fps for smooth, high-quality footage.

2. Light Sensitivity and WDR (Wide Dynamic Range):

   • Minimum light sensitivity: 0.1 lux, suitable for low-light conditions.
   • WDR ensures clarity in challenging lighting, such as glare or dim environments.

3. Field of View (FOV):

   • Horizontal FOV should be at least 110°.
   • Be cautious of inflated diagonal FOV values on packaging, as they may be misleading.

4. Data Storage:

   • SD cards with a minimum class of SDHC 6 or higher are recommended.
   • Supports loop recording to overwrite the oldest files when storage is full.

5. Additional Features:

   • Support for Additional Cameras: Useful for professional drivers (e.g., cabin cameras for taxi drivers or rearview cameras for parking assistance).
   • GPS Integration and Timestamping: Provides proof of authenticity for recorded footage.
   • Built-in Microphone: Handy for recording interactions, such as conversations with law enforcement.
   • Protected File Recording: Allows saving critical footage (e.g., accidents) to a secure file to prevent accidental overwriting.