Lecture 7: Video Intro to IT

COSC1078 Introduction to Information Technology

Lecture 7

VideoJames Harland

james.harland@rmit.edu.au

Lecture 7: Video Intro to IT

Introduction

Who is this bloke?

Lecture 7: Video Intro to IT

Overview

Questions?

WebLearn Test 1

Video

Questions?

Lecture 6: Audio Intro to IT

Introduction to IT

1 Introduction

2 Images

3 Audio

4 Video WebLearnTest 1

5 Binary Representation Assignment 1

6 Data Storage

7 Machine Processing

8 Operating Systems WebLearn Test 1

9 Processes Assignment 2

10 Internet

11 Internet Security   WebLearn Test 3

12 Future of IT Assignment 3, Peer and Self Assessment

Lecture 7: Video SE Fundamentals

Questions?

How did you spend 6-8 hours on this course last week?

This week?

Lecture 7: Video Intro to IT

Assessment Process

Submit all assignments via Blackboard in the Learning Hub

Assignment 1 due 11.59pm Sunday 1st April

Assignment 2 due 11.59pm Sunday 6th May

Assignment 3 due 11.59pm Sunday 27th May

Late assignments attract a penalty of 10% per day late, up to a maximum of 50%

Lecture 7: Video Intro to IT

Assignment

Assignment will be in three parts

Overall task is to produce a video

Groups of up to 3

Assessed by final video and group blog

Part 1: images and audio (end of week 5)

Part2: hardware (end of week 9)

Part 3: reflection, research (end of week 12)

Lecture 7: Video Intro to IT

Assignment 1

Use GIMP (or a similar tool) to perform some manipulations on an image

Use Audacity to perform some manipulations on sound

Use a movie making tool to produce something like (and much better than!) ‘Lord of the Controllers 1 & 2’

Email me your group and its name so that I can set up a blog on the Learning Hub

Lecture 7: Video Intro to IT

Overview

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Lecture 7: Video Intro to IT

And now for something completely different …

Lecture 7: Video Intro to IT

History – which came first?

Invented in 1920’s

Commercially available in 1930’s

Widespread in Australia in 1950’s Invented in 1940’s

Commercially available in 1960’s

Widespread in Australia in 1980’s

DOMINATES

STANDARDS

Lecture 7: Video Intro to IT

Video formats

NTSC National Television Systems CommitteeNorth America, Japan, Taiwan, Caribbean, …

PAL Phase Alternating LineWestern Europe, Australia, New Zealand, Asia, …

SECAM Sequentiel Couleur avec MemoireFrance, Russia, Eastern Europe, …

“TVs ain’t TVs!”

Lecture 7: Video Intro to IT

Cathode Ray Tube (CRT)

Before “flat screens” (both and )

Draws horizontal lines

Type Lines Visible

NTSC 525 480

PAL 625 576

SECAM 625 576

Lecture 7: Video Intro to IT

Cathode Ray Tube (CRT)

Top to bottom

One pass (progressive scan)

Top to bottom

Two passes (interlaced scan)

1st pass is even lines (lower field)

2nd pass is odd lines (upper field)

Can create discontinuities in slow replays

Lecture 7: Video Intro to IT

Cathode Ray Tube (CRT)

Overscan:

Not all the image is visible on the screen

Allows ‘fuzzy’ edges not to be seen

Means content cannot be placed at the very edges

Safe action area: centre 90%

Safe title area: centre 80%

Lecture 7: Video Intro to IT

Cathode Ray Tube (CRT)

Safe action area

Safe title area

Lecture 7: Video Intro to IT

Cathode Ray Tube (CRT)

Black and white: only needs luminance (what shade of grey?)

Colour: luminance + 2 x chrominance

(brightness, 2 x colour or hue)

WHY?

Lecture 7: Video Intro to IT

Cathode Ray Tube (CRT)

Black and white came first!

When colour transmission became possible, needed ability to receive colour with

Black and white: luminance onlyColour: luminance, hue, saturation

YUV used in PAL, YIQ used in NTSC (!!)Can convert RGB to/from YUV and YIQ (see material for formulae)

Lecture 7: Video Intro to IT

Sampling and Quantisation

Sampling As in image (resolution, or # pixels)

As in audio, ie frames per second

Quantisation As for images, ie bit depth per pixel

Frame aspect ratio Viewing width to height

4:316:9

Lecture 7: Video Intro to IT

Pixel Aspect Ratio

NTSC DV frame is 720 x 480 pixels

720:480 = 3:2 ≠ 4:3 ≠ 16:9 (!!!)

DV framescreen

?????

Change pixel shape via pixel aspect ratio

Lecture 7: Video Intro to IT

Conclusion

Web Test next week (week 5)

Do online quizzes later this week

Keep reading! (book particularly)

Notes for Video in Learning Hub