Lecture 7: Video Intro to IT COSC1078 Introduction to Information Technology Lecture 7 Video James Harland

Lecture 7: VideoIntro to IT Introduction to IT 1 Introduction 2 Images 3 Audio 4 Video 5 Binary Representation WebTest 1, 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 ITAssignment 3, Peer and Self Assessment

Lecture 7: VideoIntro to IT Overview  Questions?  WebLearn Test 1  Video  Questions?

Lecture 7: VideoIntro to IT Web Test 1  Quizzes are ready  Content will be on weeks 2-4 Images Audio Video

Lecture 7: VideoIntro to IT Introduction Who is this bloke?

Lecture 7: VideoIntro to IT Overview …

Lecture 7: VideoIntro 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: VideoIntro to IT Video formats NTSC National Television Systems Committee North America, Japan, Taiwan, Caribbean, … PAL Phase Alternating Line Western Europe, Australia, New Zealand, Asia, … SECAM Sequentiel Couleur avec Memoire France, Russia, Eastern Europe, … “TVs ain’t TVs!”

Lecture 7: VideoIntro to IT Cathode Ray Tube (CRT) Before “flat screens” (both and ) Draws horizontal lines TypeLinesVisible NTSC PAL SECAM625576

Lecture 7: VideoIntro to IT Cathode Ray Tube (CRT) Top to bottom One pass (progressive scan) Top to bottom Two passes (interlaced scan)  1 st pass is even lines (lower field)  2 nd pass is odd lines (upper field)  Can create discontinuities in slow replays

Lecture 7: VideoIntro 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: VideoIntro to IT Cathode Ray Tube (CRT) Safe action area Safe title area

Lecture 7: VideoIntro 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: VideoIntro 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 only Colour: 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: VideoIntro 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 4:3 16:9

Lecture 7: VideoIntro to IT Pixel Aspect Ratio NTSC DV frame is 720 x 480 pixels 720:480 = 3:2 ≠ 4:3 ≠ 16:9 (!!!) DV frame screen ????? Change pixel shape via pixel aspect ratio

Lecture 7: VideoIntro 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  Address three issues in relation to this  Lab classes 2 and 3 will be based around GIMP  Lab class 4 based on Audacity  Main emphasis is on process, not result!  In the Learning Hub now

Lecture 7: VideoIntro to IT Assignment 1

Lecture 7: VideoIntro 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