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Case Study(Teacher’s Guide) – The Advancement of Digital Video
Case Study:The Advancement of Digital Video
(Teacher’s Guide)
1
Case Study(Teacher’s Guide) – The Advancement of Digital Video
Author
Mr Hui Ka-man
Lecturer, Department of Communication Design and Digital Media
Hong Kong Design Institute
Project Coordinators
Mr Li Yat-chuen
Senior Training Consultant
Institute of Professional Education And Knowledge, VTC
MrTsang Siu-wah, Ephraim
Training Consultant
Institute of Professional Education And Knowledge, VTC
The copyright of the materials in this Case Study belongs to the Education Bureau of
the Government of the Hong Kong Special Administrative Region.
Duplication of materials in this Case Study may be used freely for non-profit making educational purposes only. In all cases, proper acknowledgements should be made. Otherwise, all rights are reserved, and no part of these materials may be reproduced, stored in a retrieval system or transmitted in any form or by any means without the prior permission of the Education Bureau of
the Government of the Hong Kong Special Administrative Region.
©Copyright 2010
Note by the Institute of Professional Education And Knowledge, VTC:
Every effort has been made to trace the copyright for the photographs and images in this Case Study as needed. We apologize for any accidental infringement and shall be pleased to come to a suitable arrangement with the rightful owner if such accidental infringement occurs.
Case Study: The Advancement of Digital Video
(Teacher Guide)
General Information
Subject: Design and Applied Technology
Level: S4-6
Learning elements:
Knowledge Contexts / Process / ImpactCompulsory Part:Strand3
Value and Impact
- Historical and cultural influences
Creative Digital Media
- Media literacy
- To understand differentmedia formats and technologies through the study of changes and development in image and video
- To understand thedifference between analog video and digital video, and their impact through the study of digital video technology development
- To understand thesocialimpacts, i.e. digital divide, of interactive television through study and discussion
- Small group discussions and presentation
- To understand the impact of new technologies on the quality of life
- Identify the features of communication via digital media
- Compare different digital media products in the local and global markets
- Evaluate the pros and cons of media-rich society in terms of social (including cultural and historical), economic and technological factors
Case Study:
Students should be made aware of the relevance of the technology they are studying to the real world. Case studies on technology and design enable students to put their learning into an authentic context, and so provide an additional resource that can add a new dimension to learning about technology and design.
Authentic Context:Through the study of the High Definition Television (HDTV) broadcasting development in Hong Kong, students could explore the social impacts of digital media development
Topics Covered:
Compulsory Part / Strand 3:Value and ImpactElective Part / Module 2:Creative Digital Media
Teaching Notes
Background
Nowadays, our society is greatly affected by the development of technology advancement. In the last decade, the boom of the internet development has changed our community in various aspects, affecting financial sector, human relationship, social welfare as well as our education system. The same phenomenon may also appear in other technology advancement – the development of the digital video; which includes the new broadcasting format (HDTV) and distribution channels (Internet, mobile, interactive TV etc).
Brief History: From Cave Painting to Video
Lascaux is the setting of a complex of caves in southwestern France famous for its cave paintings. These paintings are estimated to be 16,000 years old. They primarily consist of realistic images of large animals. Lascaux was added to the UNESCO World Heritage Sites list in 1979.
From Picture to Film
In the beginning of the motion picture development, films were made by one person with a few assistants. The film had one movement in one single short and the final movie was displayed in a special machine (such as Kinetoscope). However, technology was developed rapidly in the first 10 years, the inventors could produce several minutes long film consisting of several shots, which were made by large companies.
Another Pioneer – Lumiere brothers
Another film production pioneer is the Lumière brothers, Auguste Marie Louis Nicolas (19 October 1862, Besançon, France – 10 April 1954, Lyon) and Louis Jean (5 October 1864, Besançon, France – 6 June 1948, Bandol), were among the earliest filmmakers. The first public film screening was hold in 1895 at Paris. This history-making presentation featured ten short films, each film is 17 meters long; when hand cranked through a projector, runs approximately 46 seconds.
The poster advertising the Lumière brothers cinematographe, showing a famous comedy
(L'Arroseur Arrosé, 1895)
Source:
Television Video
Teacher Guide: Additional information for studentsThe first Television broadcast
The first regular Television broadcast started in the United States in 1928. Jenkins Television Corporation was granted the first commercial television license in United States opened the first television broadcasting station, named W3XK. However, the company was liquidated in 1932, and its assets were acquired by another company.
Digital Video
Digital video springs from the combination of two historic technologies:
TV, film and video have their roots in waveform, or what is called analog technology. Analog format was used at the very beginning of Thomas Edison’s first camera invention – the usage of film to record and present images. Film and analog video (such as VHS tape) are described as analog because they are physical representations of real images. Celluloid film uses chemical reaction of the dyes to record image.Analog video is based on continuously variable signals, which are fluctuating voltages stored on magnetic tape or some other media. In video, the changing of the voltage convey into picture or sound information.
Digital is the way in which modern computers process information. The digital process reduces all information – including pictures to a series of 0’s and 1’s. Starting in the late 70s to the early 80s, several types of video production equipment – such as Digital Video Effects (DVE) unit was introduced that operated by taking a standard analog video input and digitizing it internally. The process helps to correct or enhance the video signal, or to manipulate and add effects to the video.
The media giant, Sony, introduced Sony D-1 format in 1986. It was the first time of digital video widely used in the commercially media production industry. The format could record an uncompressed standard definition component video signal in digital form instead of the high-band analog forms.
Sony D1 Video Tape Recorder (source: www. Wikipedia.com)
In 1996, another consumer digital video format, DV tape was introduced in the market. It helps to simplifying editing process, allowing non-linear editing systems to be deployed wholly on desktop computers.
Learning Activities
A)Demonstration:
Students should investigate and tell us the differences between the following image recording media:
1)Film
2)Analog storage media – Analog audio tapes and VHS
3)Digital storage media – Compact Disc, DVD, Digital Video Tape
Teacher Guide: DemonstrationTeachers can introduce the following recording media to students:
1)Film strips
Celluloid film was the first recording media of motion pictures and photography. It can capture, process and display image in excellent quality that is still the most popular production media in the movie industry. Film displays 24 separate frames per second(fps), a speed standardized in the late 1920s when sound was introduced to the movies.
2)Analog storage media – Analog audio tapes and VHS
a) Audio tapes
Magnetic recording was developed in the 1940s and the Audio magnetic tape revolutionized both radio broadcasting and music recording industries. However, the sound quality will be lost after a few dubbing generation because of it magnetic property.
b) VHS
The Video Home System, better known by its abbreviation VHS, is a recording and playing standard developed by Victor Company of Japan, Limited (JVC) and launched in September 1976. By the 1990s, VHS became a standard format for consumer recording and viewing.
The recording medium is a ½ inch (12.7 mm) wide magnetic tape wound between two spools. It can record and playback all varieties of analog television system, including PAL, NTSC and SECEM.
However, most major film studios have stopped releasing new movie titles in VHS format in 2006 and VHS was replaced by digital media such as VCD and DVD.
3)Digital storage media – Compact Disc, DVD, Digital Video Tape
Compact Disc and DVD
A Compact Disc (CD) is an optical disc used to store digital data, originally developed for storing digital audio. The CD, available in the market since late 1982, remains the standard playback medium for commercial audio recordings to the present day.
The technology was developed by Sony and Philip Consumer Electronic. A single disc can store about 650 MB. Nowadays, most people use it to storage digital data. For entertainment industry, Audio CD is still one of the most popular music storage media and Video CD (VCD) is a standard digital format for storing video on a Compact Disc. Because of its low quality, VCD was replaced by another digital media storage format – Digital Video Disc (DVD).
Digital Video Disc (DVD) is another popular optical media storage format. It can store up to 4.7 GB data in a single disc layer. Because of its larger capacity, it can offer better picture quality than VCD. A DVD Video use MEPG 2 compression format (VCD use MEPG 1 Format) and audio is commonly stored using the Dolby Digital (AC-3) or Digital Theatre System (DTS) formats.
Digital Video Technology Development– TV production
Digital video technology is developed on the ground of the film and analog video production. We should first understand their differences and then find out how digital technology affects our lives and society.
Teacher Guide:Teachers can first introduce some basic technology backgrounds to students, including the differences between Analog and Digital, and various Analog and Digital TV format.
1) Analog and Digital - The differences
Teacher Guide: Additional information for studentsAdvantage of usage digital format for video and audio recording:
No generational Loss
Digital video can be copied with no degradation in quality. No matter how many generations a digital source is copied, it will be as clear as the original first generation of digital footage.
Compatible in various digital device
Digital data can be stored in various digital devices, such as Compact Disc (CD), Digital Video Disc (DVD), Mini Digital Tape (DV tape) and also some memory sticks. With the use of computer, digital data can be easily transferred from one device to another.
Easy for storage and distribution
Before the invention of digital storage, audio and image were captured by Film strips, which were expensive and not easy to store. Most people cannot afford to buy a film camera to record their daily living and people had to go to cinema to watch movie. Things have changed in Digital era, we can watch movie at home with the internet download movie and DVD/VCD players. Audio and motion pictures are easily stored in a small digital device such as VCD or DVD. People can create their home video with consumer digital camera and share video with others in the internet.
Easy for further edit and modification
Nowadays, we can conduct video editing in our home computer. We can also try out a variety of visual effects, add graphics and titles and use multiple videos and audios to create our movies. In this decade, most of the blockbusters are computer generated visual effects movies. Video and audio digital data are easy edited and modified in the digital computers.
Low cost
Digital video has a significantly lower cost than 35 mm film, as digital tapes can be erased and re-recorded multiple times, viewed on location without processing, and the tape stock itself is very inexpensive. By comparison, 35 mm film stock costs about $7000 per minute, including processing.
Film and TV broadcast system
Teacher Guide: Additional InformationVideo Format: Interlace and Progressive
Digital video cameras come in two different image capture formats: interlaced and progressive scan. Interlaced cameras record the image in alternating sets of lines: the odd-numbered lines are scanned, and then the even-numbered lines are scanned, then the odd-numbered lines are scanned again, and so on. One set of odd or even lines is referred to as a "field", and a consecutive pairing of two fields of opposite parity is called a frame.
A progressive scanning digital video camera records distinct frame, with both fields being identical. Thus, interlaced video captures twice as many fields per second as progressive video does when both operate at the same number of frames per second. This is one of the reasons video has a “hyper-real” look, because it draws a different image 60 times per second, as opposed to film, which records 24 or 25 progressive frames per second.
The Case: Watch clearer with HDTV
Discussion questions:
Teacher Guide: Factors affect the implementation of Digital TV1) More options for audience and better picture and audio quality
Teacher can explain to students the technical differences between Analogue TV and Digital TV. Audiences are opted to get more information from Digital TV broadcast, which provides interactive TV service, better sound and picture quality and more broadcasting channels because of the advance digital data compression technology.
Differences of TV Transmission Modes
Analogue TV / Digital TVStandard Definition TV (SDTV) / High Definition TV (HDTV)
Pixels / Highest: 720 (horizontal) x 576 (vertical) / Highest: 720 (horizontal) x 576 (vertical) / Minimum: 1024 (horizontal) x 720 or above (vertical)
Ratio of the Width and Length of Pictures / 4: 3 / 4:3 or 16: 9 / 16: 9
Sound Effects / Easily interrupted when receiving signals, “ghostly shadows” and “snowy flowers” will be shown if there is a bad reception / No ‘ghostly shadows’ and ‘snowy flowers’
Quality of the pictures as good as DVD / No ‘ghostly shadows’ and ‘snowy flowers’
Surrounding stereo sound effect
3D and layered pictures
Pixels 5 times of SDTV
Function / Interactive TV / Interactive TV
Hidden subtitles (for the convenience of people with a hearing problem )
Multi-angle visual enjoyment for special programs
Companies / TVB
ATV / Cable TV
Satellite TV
Broadband TV / Up to now:
TVB
ATV
Transmission Mode / Terrestrial Radio Frequency / Cable, satellite, broadband / Terrestrial Radio Frequency
Current Situation / Currently in use
To be suspended completely in 2012 / Currently in use / At the end of 2007, simultaneous broadcasting of both HDTV and analogue TV
In 2012, complete digital broadcasting
Charges / Free / Pay / Basic channels: free
Comparison between HDTV and Traditional TV
The sharpness of images on TV is related to the number of lines of scanning, the more the lines scanned the sharper the image will be. CRT TV that are commonly used by most of the families in Hong Kong now has only 575 lines of vertical scanning, while HDTV have 1,080, which is a double of the CRT TV.
Extracted from
Technology development: Interactive TV
Extract from GAWLINSKI MARK (2003) Interactive television production Oxford; Boston: Focal
INTRODUCTION
“in’ter.ac’tive 1. new technology that will change the way you shop, play and learn 2. a zillion-dollar industry (maybe).”
- Newsweek, May 31, 1993
BRIEF HISTORY OF INTERACTIVE TV
There are lots of articles about interactive television in the daily press or even in scientific journals.You can have an impression that interactive television is a brand new phenomenon or perhaps a technology of the future.
Actually, ITV has a long history behind it is almost as long as the history of television development itself. When television was invented experimented with in the 1920s, interactive communication, in the form of one-way video and two-way audio, was among the formats being seriously considered and tested. Since then, interactive television formats have cropped up again at regular intervals.
1950s
John Carey (1996) refers to a simple, but innovative version of interaction, which was launched in the 1950s on the CBS children’s series,“Winky Dink and you” (1953-57), in the United States. In this case, interaction was made possible by a special sheet of plastic that the children could buy and attach to the television screen. During the programs Wink Dink got into a number of predicaments, such as being chased toward the edge of a cliff by a tiger. The children were asked to help Winky Dink escape from the tiger by using a special crayon to draw a bridge on the plastic sheet.
Activity (Movie clips) / Winky Dink and YouFurther reading / In-depth: Winky Dink and You
GAWLINSKI MARK (2003) Interactive television production Oxford; Boston : Focal, p. 30-31
1960s
The beginning of interactive television’s modern era was probably AT&Ts demonstration of the “picture phone” at the World’s Fair in New York in 1964. Since then, the idea of interactivity has been tried in a myriad of contexts and disguises.
1970s
In the 1970s, Americans were presented with Warner Amex’s QUBE-system in Columbus, Ohio and Berk’s Community Television experimented with two way cable in Reading, Pennsylvania to provide interactive services involving home audiences, but failed to offer sufficient return on investment, while “Viewdata” launched its trail under the name of Prestel in England.
1980s
In the 1980s, the Americans introduced Cox Cable’s two way cable service “INDAX”(Interactive Data Exchange) either broadcast or via a telephone modem, around a model of information searching and browsing; Time Inc.’s “Teletext” in Orlando, Florida and San Diego, California; and videotext trials of Knight Ridder’s “Viewtron” service and Times Mirror’s Gateway services.