Punjab PSEB Sr. Sec. NSQF Private Security (CCTV Video Footage Auditor) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Pixel density threshold

Pixels per metre measured on the subject. Detect needs about 25 px/m, recognise about 125 px/m, identify about 250 px/m. Density at the target matters more than total camera megapixels.

I-frame versus P-frame

An I-frame is a complete coded picture. P- and B-frames store only predicted differences. Frame-accurate export must start at an I-frame, because decoding needs the preceding group of pictures.

H.265 compression

HEVC codec that typically reduces bitrate 30 to 50 percent versus H.264 at similar visual quality. It needs more processing power to decode, so older players may not support it.

PoE power classes

Power over Ethernet standards: 802.3af supplies about 15.4 watts per port; 802.3at supplies about 25.5 watts. Cameras with heaters or PTZ motors usually need the higher class.

Retention days formula

Retention days equal total usable storage divided by the product of bitrate, number of channels and 86400, then divided by 8 to convert bits to bytes.

Chain of custody record

A chronological record listing evidence ID, source device, seizure time and place, collector, and every transfer with date, purpose and signatures. It shows the item was not altered.

Write blocker purpose

Hardware or software that allows reading a storage device while blocking all write commands. It protects the original exhibit from alteration during imaging and hashing.

SHA-256 integrity hash

A cryptographic digest of a file or disk image. Record it at acquisition and re-verify before playback or export. Any change to the data produces a different hash value.

Clock offset measurement

The difference between the recorder's displayed time and a trusted reference such as NTP or a known event. Record it in minutes and seconds and apply it to every logged time.

Frame-count timing

Elapsed time equals frame number difference divided by frame rate. At 25 fps each frame is 0.04 seconds; at 30 fps each frame is about 0.0333 seconds.

Negative finding in review

A documented statement that an expected event was not present in the reviewed window. It records the channels, exact time range and search method used.

Event log fields

Sequential log number, channel, on-screen timestamp, corrected real time, event category, persons or objects involved, action taken, and reviewer initials.

Enhancement disclosure rule

Brightness, contrast and sharpening may be applied if disclosed. Content must never be added, removed or generated. Each derivative records the tool, version, settings and resulting hash.

Lossless still export

Saving evidential frames as PNG or TIFF avoids the quality loss caused by repeated JPEG compression. Each save of a JPEG re-encodes and degrades the image.

Tamper-evident seal

A seal that shows visible damage if opened. Its number is recorded on the custody form at sealing and checked at each handover to detect unauthorised access.

Admissibility criteria

Courts commonly test relevance, authenticity verified by hash and custody records, completeness with no unexplained gaps, reliability of the source, and lawful acquisition of the footage.

Bharatiya Sakshya Adhiniyam 2023

Indian evidence statute replacing the Indian Evidence Act, 1872. It governs proof of electronic records and requires a certificate in the prescribed form for electronic evidence.

DPDP Act 2023 basics

India's data protection law. Processing personal data needs a lawful purpose with consent or a specified legitimate use, plus security safeguards and breach notification to the Data Protection Board.

CCTV signage requirement

Notices placed before entry to a monitored area stating the purpose of surveillance, who operates it, contact details, and which zones are covered.

Finding statement pattern

State what was observed, the exhibit and channel, camera time plus corrected time, the confidence level, and what the observation does or does not prove.

Fact versus opinion

Observations describe what appears on the footage. Interpretation explains meaning. Each must be labelled separately, and opinion must stay within the auditor's demonstrated competence.

Report limitations section

Lists resolution limits, frame rate, blind spots, recording gaps, measured clock offset and unverified assumptions, so readers can judge how far the conclusions extend.

Second-reviewer check

Before issue, another qualified person rechecks hashes, time calculations and exhibit references. The reviewer's name and date are recorded in the report file.

Control-room operator duties

Monitor live feeds, respond to alarms, log events, dispatch patrols, and immediately preserve and hash relevant footage after any incident before overwrite occurs.

Preservation trigger

Any incident, alarm or complaint activates immediate export and hashing of the relevant footage, because the recorder's ring buffer will overwrite it once retention is reached.

Shift handover record

A signed briefing covering open incidents, equipment faults, trespass notices and pending evidence exports, passed from outgoing to incoming staff at every shift change.

20-20-20 eye rule

Every 20 minutes of screen work, look at something about 20 feet away for 20 seconds. It reduces eye strain during long footage review sessions.

DRABC first aid

Danger, Response, Airway, Breathing, Circulation. Check each in order before giving aid, call emergency services, and record the time of collapse and interventions.

India emergency numbers

112 is the all-in-one emergency number; 100 police, 101 fire, 108 ambulance. These should be displayed prominently in every control room.

Lone worker check-in

A lone patrol or auditor checks in at agreed intervals by radio or phone, and logs the start and end of the assignment so someone knows their location.

Need-to-know disclosure

Footage and incident details are shared only with persons having a lawful basis and operational need. Each disclosure is recorded with date, recipient and purpose.

Log correction method

Errors are corrected with a dated, signed strike-through and a written reason. Entries are never erased, backdated or overwritten, preserving the record's integrity.