Fun With Acronyms Flashcards
SWGDE
Scientific working group on digital evidence
LEVA
Law enforcement and emergency services video association, international inc
501(3) nonprofit
FVA
Forensic video analysis - THE SCIENTIFIC EXAMINATION, COMPARISON, AND/OR EVALUATION OF VIDEO IN LEGAL MATTERS
AR
Aspect ratio - relates to the image/video
PAR
Pixel aspect ratio - relates to a camera/monitor
SAR
Storage aspect ratio (dimensions of a frame, expressed as a ratio)
DAR
Display aspect ratio - pixel aspect ratio/how image should look
ITU
International television union
DME
Digital multimedia evidence (info of probatice value stored or transmitted in binary form - film, tape, magnetic/optical media, etc)
IR
Infrared - wavelength just below visible light spectrum
YCbCr
Luminance, chromatic blue, chromatic red
Embedded DVR
Digital video recorder - specialized computer designed for capture of digital video; analog to digital conversion takes place within box; OS and application software is contained on firmware or read-only memory (ROM) within system
PC-based DVR
Digital video recorder - general purpose computer running additional software which allows PC to function as a DVR; OS is installed on computer main storage; analog to digital conversion still happens at DVR
NVR
Network video recorder - records a digital video stream; can be embedded or PC-based; distinguished by lack of analog inputs; analog to digital conversion is done at camera
POE
Power over ethernet
NAS
Network attached storage; used with NVR
LAN
Local area network - A local area network is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building (closed circuit)
ACE-VR
Analyze, compare, evaluate, verify, report
CCTV
Closed circuit television - tv system which sends signals to a limited number of monitors/recorders
CRT
Cathode ray tube camera - first electronic camera; used from 1930s to 1980s
CCD
Charge coupled device - camera which replaced CRTs; an array of light sensitive diodes on a silicon chip; lens focuses light onto CCD, which uses diodes to translate lights into an electrical charge which is carried outside CCD in a bucket brigade system; either three CCDs for RGB color in camera, or one CCD with an RGB filter over it
IP camera
Internet protocol camera - digitizes values from a CCD or CMOS, compresses the images, and streams video using IP; has built in web servers to allow configuration and viewing of camera
CMOS
Complimentary Metal oxide semiconductors - used in solid state cameras; similar to CCD except light diodes are read directly instead of bucket brigaded around as electrical signals
NTSC
National television standards committee - set standards for signals on standard definition tv
LCD
Liquid crystal display - currents applied to twisted crystals untwists them; constantly backlit by diffused white light; layers of polarizing film between light and crystals, crystals and screen; grid of transistors arranged on glass substrate behind crystals; crystals twist to allow RGB colors to filter through
ECPA
Electronic communications privacy act - service providers could distribute users’ info without government permission; email privacy act amendment requires warrant for emails and cloud data
SCA
Stored communications act - data only acquired with subpoena or search warrant, barring exigency or voluntary disclosure
Transactional data only requires a subpoena
Content data requires search warrant
USB
Universal Serial Bus (USB) is an industry standard that specifies the physical interfaces and protocols for connecting, data transferring and powering of hosts, such as personal computers, peripherals, e.g. keyboards and mobile devices, and intermediate hubs.
FTK
Forensic tool kit - software created by access data
SSD
A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage - no mechanical parts within, just electronic circuits
HDD
A hard disk drive (HDD), hard disk, hard drive, or fixed disk,[b] is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnetic material
NTFS
New technology file system - used by removable storage devices
IAI
International association of identification
RLE
Run-length encoding - replaces runs of repeating symbols with one copy of the symbol and a number
AAAAA -> A5
An example of lossless compression
JPEG
Joint photographic expert group - a lossy compression algorithm; associated with JFIF (jpg file interchange format) and EXIF (exchangeable image file format)
DCT
Discrete cosine transform - transforms 8x8 block of pixels from luminence to frequency
Doesn’t measure the luminence value of the pixel, but rather how often that value occurs within the image
MJPEG
Motion jpeg - Jpegs displayed in succession to give sense of motion
MPEG
Moving pictures expert group - from Hollywood film industry, MPEG 2 (DVD) and mpeg 4 (blue ray)
VCEG
Video coding experts group - from teleconferencing, .H264
JCT-VC
Joint collaborative team on video coding - collab between mpeg and vceg, created .H264 and .H265; hi-def for video and internet
GOP
Group of pictures - group of I, p, and b frames interdependent on each other for compression; group beginning and ending defined by I-frame boundaries
MD5
Message digest 5 - 128-bit hashing algorithm; 32 hexadecimal key
SHA1
Secure hash algorithm - 160-bit, 40 hexadecimal key
VLC
Video LAN - open source project which runs on all computers and supports most container formats
AVI
Audio visual interleave - open source video container, derived from resource interchange file format (RIFF)
IFF
Interchange file format
RIFF
Resource interchange file format
FFmpeg
Fast Foward Moving Pictures Expert Group - FFmpeg is a free and open-source software project consisting of a suite of libraries and programs for handling video, audio, and other multimedia files and streams. At its core is the command-line ffmpeg tool itself, designed for processing of video and audio files. It is widely used for format transcoding, basic editing (trimming and concatenation), video scaling, video post-production effects and standards compliance
MKV
Matroska Video File - Matroska Video files, also known as MKV videos, are container files that support unlimited picture, audio, and subtitle tracks. They’re similar to MOV and AVI files, except they have a much larger amount of storage
TIFF
Tagged image file format; lossy or lossless
BMP
Windows bitmap; uncompressed
PNG
Portable graphics format; lossless
NAS
Network Attached Storage - only input and output is the network; accessible by network file sharing protocols; need a client to access data
NTP
Network Time Protocol (NTP) is a protocol that allows the synchronization of system clocks (from desktops to servers)