Glossary of Security Camera and PC Storage Terms

Content-based duplicate detection

Content-based duplicate detection compares what is inside files rather than their names, dates or sizes alone, so renamed copies are still recognized as duplicates.

Detection mask (motion zone)

A detection mask marks parts of the camera image to ignore, such as a busy road or swaying trees, so motion detection only reacts to the areas you care about.

DVR (digital video recorder)

A DVR records video from analog (coaxial) security cameras. Unlike an NVR, it encodes the video itself because analog cameras do not send digital streams.

File hash (checksum)

A file hash is a short fingerprint calculated from a file's contents. Two files with the same hash are, for practical purposes, identical, which makes hashes a fast way to confirm duplicates.

Frame rate (fps)

Frame rate is the number of video images captured per second. Security cameras commonly record at 15 to 30 fps; lower frame rates save storage space.

H.264 and H.265

H.264 (AVC) and H.265 (HEVC) are video compression formats used by most IP cameras. H.265 produces smaller files at similar quality but needs more processing power to decode.

Hardware video decoding

Hardware decoding uses the graphics processor (GPU) to decompress video instead of the main processor (CPU). It keeps multiple live camera streams smooth while using less CPU.

IP camera

An IP camera is a security camera that sends video over a computer network (Ethernet or Wi-Fi) instead of a USB or analog cable. It has its own IP address and can be viewed and recorded by software anywhere on the network.

Motion detection sensitivity

Motion detection sensitivity controls how much change between video frames counts as motion. Higher sensitivity catches smaller movements but produces more false alarms from shadows, rain or insects.

NVR (network video recorder)

An NVR is a device or program that records video from IP cameras. Software such as SecureView lets a Windows PC act as the recorder instead of a separate NVR box.

ONVIF

ONVIF (Open Network Video Interface Forum) is an industry standard that lets IP cameras, recorders and viewing software from different manufacturers discover each other and work together. An ONVIF-compatible camera can be added to any ONVIF-compatible app, such as SecureView.

PTZ (pan-tilt-zoom)

PTZ describes a camera that can be moved remotely: pan (left/right), tilt (up/down) and zoom (in/out). PTZ cameras can be controlled through ONVIF from compatible software.

RAW image file

A RAW file (such as .CR2, .NEF or .ARW) stores unprocessed image data from a camera sensor. RAW files are large, so duplicate RAW photos use a lot of disk space.

Recycle Bin

The Recycle Bin is where Windows moves deleted files so they can be restored. Files deleted permanently skip the Recycle Bin and cannot be restored from it.

Resolution

Resolution is the number of pixels in each video frame, such as 1280x720 (720p) or 1920x1080 (1080p). Higher resolution shows more detail but uses more storage and bandwidth.

RTSP

RTSP (Real Time Streaming Protocol) is a network protocol used to request and control live video streams. Most IP cameras publish an RTSP URL, for example rtsp://192.168.1.20:554/stream1, that video software can open to show the live feed.

Similar image detection

Similar image detection finds photos that look alike even when their files differ, for example the same picture saved at a different size, quality or format.

Storage Sense

Storage Sense is a built-in Windows feature that automatically frees space by deleting temporary files and emptying the Recycle Bin on a schedule. It does not look for duplicate files.

Windows Credential Manager

Windows Credential Manager is the built-in Windows vault for saved usernames and passwords. It encrypts credentials and ties them to your Windows user account.

WS-Discovery

WS-Discovery (Web Services Dynamic Discovery) is the protocol ONVIF uses to find cameras on a local network automatically, so you do not have to type in each camera's IP address.