Educational

Video Principles and Technologies

1 What is H.264?

H.264 is an industry standard for video compression, the process of converting digital video into a format that takes up less capacity when it is stored or transmitted. Video compression (or video coding) is an essential technology for applications such as digital television, DVD-Video, mobile TV, videoconferencing and internet video streaming. Standardising video compression makes […]

H.264/AVC Inter Prediction

1 Introduction This document describes the methods of predicting inter-coded macroblocks in P-slices in an H.264 video compression codec. Inter prediction creates a prediction model from one or more previously encoded video frames. The model is formed by shifting samples in the reference frame(s) (motion compensated prediction). The AVC CODEC uses block-based motion compensation, the same […]

H.264/AVC Context Adaptive Binary Arithmetic Coding (CABAC)

1 Introduction The H.264 Advanced Video Coding standard specifies two types of entrop coding: Context-based Adaptive Binary Arithmetic Coding (CABAC) and Variable-Length Coding (VLC). This document provides a short introduction to CABAC. Familiarity with the concept of Arithmetic Coding is assumed. 2 Context-based adaptive binary arithmetic coding (CABAC) In an H.264 codec, when entropy_coding_mode is […]

H.264/AVC Context Adaptive Variable Length Coding

1 Introduction The H.264 / AVC standard specifies two types of entropy coding: Context-based Adaptive Binary Arithmetic Coding (CABAC) and Variable-Length Coding (VLC). The Variable-Length Coding scheme is described in this document. 2  Coded elements Parameters that require to be encoded and transmitted include the following (Table 21). Above the slice layer, syntax elements are […]

H.264/AVC Loop Filter

1 Introduction This document describes the methods of filtering reconstructed blocks in an H.264 video compression codec. 2 Description of reconstruction filter A filter can be applied to every decoded macroblock in order to reduce blocking distortion. The deblocking filter is applied after the inverse transform in the encoder (before reconstructing and storing the macroblock […]

H.264/AVC Picture Management

1 Introduction This document introduces the parameters and processes involved in managing coded frames within the H.264/AVC standard. This document is informative only and readers should refer to the standard for accurate definitions of the parameters and processes described here. A frame or field of video is decoded from an access unit (a series of […]

H.264/AVC 4×4 Transform and Quantization

1 Overview In an H.264/AVC codec, macroblock data are transformed and quantized prior to coding and rescaled and inverse transformed prior to reconstruction and display (Figure 1). Several transforms are specified in the H.264 standard: a 4×4 “core” transform, 4×4 and 2×2 Hadamard transforms and an 8×8 transform (High profiles only). Figure 1 Transform and quantization in […]

Security

Top Security Threat #1 – Advanced Malware

Survive the Epidemic of Advanced Evasive Malware Whether as old-fashioned virus attachments in email, trojans delivered through network attacks, or modern ransomware forced through drive-by download web attacks, malware has long been the bane of IT organizations. So what is advanced malware and how does it work? As the name suggests, malware is software designed […]

Top Security Threat #2 – Data Loss

Protect Your Most Sensitive Asset from Compromise Data is the life blood of your business. You can replace computers, re-install software and repair networks, but recovering from a major data loss is no simple task. What Causes Data Loss and How Big Is the Threat? Information security experts often talk about how to protect your […]

Top Security Threat #3 – Ransomware

Don’t Be the Next Victim of Ransomware Ransomware is an increasingly common method of attack for hackers against individuals, SMBs and enterprises alike. While the first incidents of ransomware were discovered in as early as 2005, the last three years have seen this type of threat explode in popularity and compromise millions of computers and […]

Top Security Threat #4 – Unsecured Wireless Networks

Take Control of Your Wireless Network Airspace Experts estimate that 63% of all Internet traffic in the world will travel over Wi-Fi by 2019. Much of this traffic will come from the workplace, as reduced costs and easier management continue to spur the adoption of wireless networks. Unfortunately, rapid rollouts of wireless networks often come […]

Top Security Threat #5 – Network Blind Spots

See Threats Before It’s Too Late In an increasingly unpredictable threat environment, security breaches are becoming harder and harder to detect. Malware, backdoors, and data loss routinely go unnoticed for months, and in some cases years at a time. When the breach is finally discovered, it is usually reported by an external party and rarely […]

Cloud Computing

AWS amazon_web_services

AWS Solution Architect – Associate – A Web Series

I have been studying for the AWS Solution Architect – Associate Certification through Amazon Web Services for some time and now I am down to the project portion. Over the next few days I will be working on projects as listed below. I will be making posts available with the answers and screenshots of my […]

AWS amazon_web_services

Episode 1 – AWS Solution Architect – Associate

I have been studying for the AWS Solution Architect – Associate Certification through Amazon Web Services for some time and now I am down to the project portion. Over the next few days I will be working on projects as listed below. I will be making posts available with the answers and screenshots of my […]

AWS amazon_web_services

Episode 2 – AWS Solution Architect – Associate

I have been studying for the AWS Solution Architect – Associate Certification through Amazon Web Services for some time and now I am down to the project portion. Over the next few days I will be working on projects as listed below. I will be making posts available with the answers and screenshots of my work for everyone to see.

10 new AWS cloud services you never expected

From data scooping to facial recognition, Amazon’s latest additions give devs new, wide-ranging powers in the cloud By Peter Wayner | Follow | Contributing Editor, InfoWorld | Jan 23, 2017 3:00 AM PT In the beginning, life in the cloud was simple. Type in your credit card number and—voilà—you had root on a machine you […]

Networking 101

What is a Subnet?

A subnet is division of an IP network (internet protocol suite), where an IP network is a set of communications protocols used on the Internet and other similar networks. It is commonly known as TCP/IP (Transmission Control Protocol/Internet Protocol). The act of dividing a network into at least two separate networks is called subnetting, and […]

BGP

Networking 101: Understanding BGP Routing

BGP – Border Gateway Protocol can be critical for successful enterprise network administration. BGP – The Border Gateway Protocol (BGP) is the routing protocol of the Internet, used to route traffic across the Internet. For that reason, it’s a pretty important protocol, and it can also be the hardest one to understand. From our overview […]

IPSec - Internet Security Protocol

IPSec – Internet Protocol Security

IPSec is one of the new buzz words these days in the networking security area. It’s becoming very popular and also a standard in most operating systems. Windows 2000 fully supports IPSec and that’s most probably where you are likely to find it. Routers these days also support IPSec to establish secure links and to […]

IPSec VPN - Let Me Explain

Understanding VPN IPSec – Let Me Show You.

IPSec VPN protocols objective is to provide security services for IP packets such as encrypting sensitive data, authentication, protection against replay and data confidentiality. As outlined in our IPSec protocol article, Encapsulating Security Payload (ESP) and Authentication Header (AH) are the two IPSec security protocols used to provide these security services.  Analysing  the ESP and […]