video technologie

8/8/2019 Video Technologie

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CLASSROOM TEACHING

TECHNIQUES ARE EASILY

ADAPTED FOR VIDEO, AND VIDEO

IS AN EASY DISTANCE DELIVERY

FORMAT FOR NEW PARTICIPANTS

TO ADAPT TO

INTRODUCTION TO

VIDEO TECHNOLOGIES

FOR DISTANCE

EDUCATION

VIDEO IS AN INCREASINGLY

important part of many distanceeducation programmes, as it

provides a visual and auditorycontext for learning. The

necessary equipment need notbe prohibitively expensive, and

the range of options forvideoconferencing connectivityand video distribution includetraditional videotape, video

broadcast (instructionaltelevision), interactive

videoconferencing, desktop

videoconferencing and streamingvideo.

Advantages of video

technologies

Video and videoconferencing arecurrently the most convenient

means to reproduce, at adistance, the social atmosphereof an ordinary classroom. Both

verbal and visual interaction arestrongly represented on video, so

the format is highly accessibleand inclusive – classroom

teaching techniques are easilyadapted for video, and video is

an easy distance delivery formatfor new participants to adapt to.

Video’s face-to-face contextengages the students, and videocan effectively capture culturalcontext to enhance the learning

experience. Videoconferencingcan significantly broadenlearning opportunities,



particularly for rural schools.Desktop systems for

videoconferencing and streamingvideo are increasingly available

and affordable, as are alternative

distribution formats to traditionalbroadcasting (videotape, CD-

ROM, DVD).

Disadvantages of video

technologies

Costs for video broadcast andtraditional videoconferencing are

still high. Video andvideoconferencing both need

high bandwidth modem

connectivity; although somestreaming video can be accessed

with a low bandwidth modem,transmission may be choppy and

participants must still have areliable phone connection.

Videoconferencing takes place ata fixed hour in a dedicatedfacility, which may limit its

usefulness to people who workon shifts or with erratic

schedules. Learning throughvideoconferencing is by naturegroup-paced, not self-paced; thismay not suit every individual’s

learning style.

Both video andvideoconferencing lean heavily

toward a traditional lectureformat, which can encourage

passivity in participants similar towatching television. For this

reason, the medium does not

necessarily transmit detailedfactual content well; presenters

must adapt their approach,providing supplementary

materials in alternative formats if necessary.

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TOP OF ARTICLE KNOWLEDGE SERIES INDEX

http://www.col.org/Knowledge/ks_videoconferencing.htm#TOPOFPAGE%23TOPOFPAGE

http://www.col.org/Knowledge/index.htm





TRADITIONAL

VIDEOCONFERENCING

For the past six years, Heritage College(Hull, Québec) distance educationprogrammes have enabled aboriginal Creeadults to take preparatory college-levelcourses by videoconferencing, withoutleaving their home communities in theremote James Bay region of northernQuébec.

Multi-site conferences are transmitted fromthe college over a single ISDN connection(two, high bandwidth digital phone lines) bydialling in to a conference bridge.Participants at each site can see and hear

the instructor, and be seen and heard whencalled upon. The students attend classesfrom their local adult education centres,communicating with their instructor bytalking during the videoconference and byreceiving or sending images from adocument camera.

The choice of when and how to usevideoconferencing is based on the needs of participants and the requirements of thecontent being delivered. In this instance,videoconferencing is well suited to the Creestudents’ preference to learn by seeing howsomething is done, and by hearing what it’sused for.

Equipment and costs for traditional

videoconferencing

Basic classroom/boardroomvideoconference equipment packagesinclude a video camera, microphone, and acodec - a digital encoder/decoder – thatconverts analogue images into digitalsignals. These signals are compressed andtransmitted by high bandwidth phone linesto and from the receiving sites, anddisplayed on standard large-screentelevisions. A remote control keypadcontrols camera movement and soundlevels.

Presenters will often have the option of using peripheral devices, such as:

• A document camera, which displays

physical objects, documents, or notes shownlive by the presenter



• A split-screen function, for viewingseveral sites on-screen at once (typically upto four)

• A PC (personal computer)input/output to transmit displays from data

files

• An electronic whiteboard, useful if the presenter is facilitating a group locallywhile simultaneously conferencing withremote sites

• A second TV screen, for a view of both the local andremote sites

• Electronic polling devices, whichallow large groups of participants to vote orrespond to questions electronically ratherthan verbally.

If traditional videoconferencing facilitiesneed to be purchased rather than rented,they may be expensive to maintain. Carefulplanning, shared usage and timemanagement are often necessary to justifyhigh operating costs. Besides usingvideoconferencing for distance education,for example, a rural school board can usethe system to hold administrative meetingsor to conduct job interviews, saving traveltime and costs.

Fixed costs for a single, site-to-sitevideoconference include:

• Equipment purchases (currentlyUS$3,000 – $7,000 per site); where available,private videoconferencing rooms can berented

• Long distance charges on a minimumof two digital phone lines (charged to theoutgoing call)

• Salaries of any technical personnel

(including the presenter) engaged for theconference.

Variable costs include the above, plus:

• Equivalent costs for each additionalparticipating site

• Multi-site bridge administrationcharges, including registration or schedulingfees

• Additional long distance charges for

connecting with sites outside the bridge’s



local calling area.

Videoconferencing tips

As the dynamics of on-screen interaction –

especially where multiple sites are involved– can become somewhat chaotic, videoconferences often need more planning andmanagement than face-to-face meetings.

Room and camera set-up

• Seating arrangements: a U-shapedgroup seating arrangement transmits wellvisually.

• Camera angles: avoid extremeclose-ups. Placing the camera just above the TV monitor can help a sense of eye contact,as people will look at the monitor image of the person they are talking to. Camerasettings can be saved as numbered pre-setson the control keypad.

• Consistent lighting: lighting andframing subjects in the camera viewfindershould follow the guidelines for basicphotography, with ample controlled lightingto ensure both subject and background areevenly lit.

• Microphone placement:videoconference system microphones shouldbe aimed away from the television speakersand the hum of electronic equipment.

• Support equipment: a fax machinefor transmitting hard copies of notes and aseparate speaker phone, in case anytechnical troubleshooting needs to be donewith someone attempting to connect to theconference.

Presenter strategies

• Prepare: class materials should beready at hand and organised.

• Body language: avoid rapidmovements, pacing around or erratic handgestures. Make distinct movements, e.g. takeslow steps forward or backward, and usespecific hand gestures where needed foremphasis.

• Voice: speak clearly but in a naturalvoice, at a comfortable volume. Energy and

enthusiasm are critical in motivatingparticipation, so voice quality (pitch, tone,



volume and pacing) is important.

• Clothing: wear solid colours andsimple jewellery. Flashy jewellery or brightcolours (including white and striped clothing)do not transmit well in compressed video.

• Movement: avoid moving off camera, or too close or far away from thelight source; your image will be "cut off" orappear too light or dark on screen. Thevideoconferencing inset window can be usedto monitor how the image looks at theremote site.

• Visual aids: both the presenter andremote-site participants can use a documentcamera or electronic whiteboard.

• Pacing: there can be a delay

between the time a person talks at one site,and the time he or she is actually heard atthe remote site. Presenters should pause fora longer than normal period of time whenexpecting a response.

• Monitor questions: use atimesaving question format, e.g. "Is thereanyone who did not understand?" instead of "Does everybody understand?".

Encouraging interactivity

• Prepare participants: distributepre-readings or questions. Notify participantsearly in the session about specific discussiontopics.

• Establish rapport: use socialicebreakers, such as having participantsintroduce one another. The presenter shoulddraw on common interests between groupmembers at different sites. Participantsshould identify themselves when they speakand learn others’ names.

• Monitor participation: pay as muchattention to the remote sites as to the hostsite. Address questions to specific groups orsites but not to specific individuals, unlessthey are clearly comfortable with this. Avoidan over-emphasis on the presenter readinghis or her material.

• • • •








DESKTOP VIDEOCONFERENCING

OVER THE INTERNET

Cathy Gunter has used videoconferencingas a teaching tool at the Provincial Schoolfor the Deaf in British Columbia since themid-1990s. Deaf students are very visualand frequently have lower literacy skillsthan their hearing peers. An early projectconnected students at the school withanother school for the deaf in St. John’s,Newfoundland. As a teacher, Ms. Gunterfinds videoconferencing a "fairlyinexpensive method of connecting with the

outside world and to get information firsthand . . . We have visited the San DiegoZoo, the Museum of Modern Art in New York." Conferences are interpreted usingAmerican Sign Language (ASL).

Equipment and costs

Using the Internet greatly reduces the costof videoconferencing, but the quality of thetransmission is also reduced. Internet-basedvideoconferencing from a desktop PC

requires:

• A webcam: a digitalcamera (US$80 – $200) thatattaches to a PC

• A sound card

• Speakers

• A microphone, or aheadset that combinesspeakers and a microphone

• Conferencing software,

such as NetMeeting orCuSeeMe Pro

• Internet access at 56Kbps.

Internet conferencing software

Two inexpensive desktop conferencingsoftware packages are NetMeeting,available free from Microsoft (newerversions of Microsoft Windows include acopy of NetMeeting) and CUSeeMe, whichcan be purchased along with aninexpensive camera for under US$100.




VIDEO BROADCAST

Carleton University (Ottawa, Ontario) hasoffered courses over the local cabletelevision network since 1978(www.carleton.ca/itv). Despite many newdevelopments in the videoconferencing andInternet arenas, Carleton’s "old technology"approach to distance delivery remainsviable – it is streamlined, cost-effective andpedagogically sound.

By broadcasting over the metropolitan

cable television network, Carleton offers itsmost popular courses to a greater numberof students while avoiding class-schedulingconflicts. Today, roughly 70% of theapproximately 4,500 students annuallytaking Carleton’s television courses alsoattend other courses on campus. Theremaining 30% are distance educationstudents. Through its "Tapes-to-You"videocassette courier service, Carleton isadditionally able to reach students acrossNorth America. The university is currentlyresearching the possibility of distributing

video courses using CD-ROM (see "VideoCD" section at the end of this paper).

Courses are deliberately filmed in aclassroom environment, which includesactual on-campus participants. The existingclassroom setting reduces costs and is anaturally dynamic environment for bothinstructor and students. The classroom isequipped with a multi media teachingconsole, a multi media computer, 35mmslide-to-video player, VHS video player andan overhead document video camera. Pre-recorded tapes, 35mm slides and computerapplications (such as PowerPoint) can bepresented to the on-site class and recordedas part of the taped lecture.

• • • •




http://www.carleton.ca/itv





http://www.carleton.ca/itv





VIDEO STREAMING

An emerging, less expensive option to fullbroadcast video is "streaming" sound andvideo over the Internet. The video is

streamed through the computer anddisplayed on the screen without needing tobe saved onto its hard drive, as most harddrives are not large enough to store awhole video programme. Streaming videocan also be broadcast simultaneouslyaround the world (called live streaming orwebcasting), or archived and accessed asrequired.

A good way to learn about streaming videoand its uses is to sample it. Learning WeekLive is a weekly webcast (a real time,

Internet video broadcast) featuring videostreaming, slides and online chat, broadcastfrom an online streaming platform calledHorizonLive. The appeal of HorizonLive is itsvariety of visual content. Simple visuals(usually, "talking heads") can be enrichedby adding electronic slides (e.g.PowerPoint), web pages, text chat andpolling features. HorizonLive alsoincorporates a whiteboard and the ability toautomatically capture and display screenshots through a programme on the viewer’sPC.

Streaming video captures images using adigital video camera or camcorder, andcompresses the video file using video-encoding software. A video capture cardtranslates the digital video file into datasignals that a computer can read, andtransfers that information from the camerato the PC; analogue formats, such as anexisting programme on videocassette, canalso be transferred this way. FireWire is thecurrent standard for capturing digital video

through a digital video port on yourcomputer. Watch for FireWire or iLinkcompatibility when purchasing videohardware and software.

Most streamed video comes in one of threeflavours: Microsoft Windows Media (ASF orAdvanced Streaming Format),RealNetwork’s RealVideo, or AppleQuickTime (Windows and Macintoshplatforms).

Players for streamed videos are free, but aseach format is distinct students may needto have a copy of each player on their



computer if more than one format is beingused. Most sites with streaming videoinclude a link to the appropriate player, andhave information about the specificcomputer configuration required to access

the video.

Typically, the minimum Windows-platformrequirements for viewing video over theInternet are:

• A Pentium 166 MHzprocessor

• 32MB of RAM

• A 28.8 Kbps or bettermodem

(a faster connection willimprove video quality)

• A 16-bit sound card

• Speakers

• A 256-colour videodisplay card

• Windows 95 or higher(Windows MediaPlayer 7.1requires Windows 98, butearlier versions are availablefor Windows 95 and Windows

NT).

Because streaming video involvescompressing data for transmission over acomputer network, even the very highestquality streaming media signal does notquite equal the image quality of analogueformats (videotape, or traditional broadcasttelevision).

Producing streaming video

This requires a good quality video camera,ideally a digital camcorder. Although it ispossible to use an analogue videocamcorder, the quality of a digitallycaptured image will be noticeably better.Prices vary considerably, but acceptablequality digital video camcorders cost aboutUS$1,200; a 60-minute digitalvideocassette costs approximately US$10.It is also possible to record video and audiostreaming content using other types of media devices, such as audiotape,videotape, CD-ROM, or satellite feeds.

Streaming also requires software for



encoding and compressing video. WindowsMedia, RealNetworks and QuickTime eachhave proprietary products. Basic encodingsoftware, such as RealNetworks’RealProducer Basic, is inexpensive and

sometimes free.

For detailed product information oravailability, and for streaming video "how-to’s," see:

• Windows Media( www.microsoft.com/windows/windowsmedia/default.asp )

• RealNetworks (www.realnetworks.com/getstarted)

•

QuickTime (www.apple.com/quicktime/products/qt )

Digital video editing software lets users cutand paste, add text and other effects to avideo. RealProducer Plus and iMovie(www.apple.com/imovie) are affordablebeginner video editing products. AdobePremiere(www.adobe.com/products/premiere ) andFinalCut Pro (www.apple.com/finalcutpro )are more sophisticated products that

require training and skill to use effectively.Simple "talking heads" productions may notrequire sophisticated editing.

Equipment and tools for capturing andediting digital video on a PC are designed tostreamline the process, but producing goodquality video can still be tricky. You needgood equipment, significant bandwidth, alarge computer hard drive and considerabletime to produce streaming videosuccessfully. It can also be costly, especially

if you intend to run your own streamingvideo server (required for a large,simultaneous audience) to monitor thevideo downloading process. Instead of a"do-it-yourself" mentality, institutionsshould consider using the technical supportservices of application service providers(ASP’s) such as Horizonlive(www.horizonlive.com), WebEx(www.webex.com) and CentraNow(www.centranow.com). These onlineservices offer video streaming andvideoconferencing features in an integrated

learning platform.

http://www.microsoft.com/windows/windowsmedia/default.asp


http://www.realnetworks.com/getstarted

http://www.apple.com/quicktime/products/qt


http://www.apple.com/imovie

http://www.adobe.com/products/premiere

http://www.apple.com/finalcutpro

http://www.horizonlive.com/

http://www.webex.com/

http://www.centranow.com/



http://www.realnetworks.com/getstarted




http://www.adobe.com/products/premiere

http://www.apple.com/finalcutpro



http://www.centranow.com/



Tips for effective video streaming

Ideally, institutions interested in producingstreaming video should involve someone

skilled with using a video camera and whohas some technical video knowledge. Hereare some other suggestions:

• Events should be under 90 minutes,and structured around a few basic themes. Thirty to 60 minute events are consideredmost effective

• Use good quality equipment andcheck wiring connections; a faulty connectioncan cause loud background noise

• Use a clip-on microphone or a podiummicrophone directly attached to yourrecording device, to reduce backgroundnoise

• A simple backdrop for the subject isbest

• Close shots with minimal movementwork better than far away or "action" shots of the subject

• Avoid a lot of camera movement orzooming, which are difficult to effectivelycompress; use motion only where it clearlycompliments the learning experience, aswhen demonstrating an action relevant tothe topic presented

• Visuals that accompany a videopresentation should be simple but effective,including a mix of photos, simple graphicsand well-designed text.

Video CD

Because Internet connectivity is still

sporadic or slow in many parts of the world,producing and distributing video on CD-ROM is an attractive option – the downsideis that you need to distribute the physicaldisc. MPEG1, Real and Quicktime arecommon file formats that can store slightlymore than an hour of audio and video on aCD-ROM, which is normally adequate fordistributing a class lecture. To produce avideo CD you will need a camcorder, avideo capture card, a high-end Pentiumcomputer with a very large hard drive,software to capture, edit and encode the

video, and a CD-writer to write theinformation onto a disc. InterVideo’s MyDVD



for CD is an example of a video-authoringpackage; WinProducer and Apple iMoviealso let you export videos to a CD-ROM. Tolearn more about producing video CDs, see:

desktopvideo.about.com/compute/desktopvideo/library/weekly/aa061901a.htm

• • • •

COL HOME PAGE TOP OF ARTICLE KNOWLEDGE SERIES INDEX

REFERENCES

An Introduction to QuickTime developer.apple.com/quicktime/qttutorial

ASTD Virtual Community astdppu.webex.com

Classroom Conferencing gsh.lightspan.com/cu

The Commonwealth of Learning Streamed Videos www.col.org/videos

Cookbook for shooting good video for streaming. www.utexas.edu/cc/cit/streaming

CUworld www.cuworld.com

Current Awareness Resources via Streaming Audio and Videowww.gwu.edu/gelman/ref/readyref/news.html

DeskTop Movies in Education www.apple.com/education/dv

DeskTop Video – About.com desktopvideo.about.com/compute/desktopvideo

First Virtual Communications: web conferencing productswww.fvc.com/eng/webconferencing

HorizonLive: learning delivery platform with streaming. www.horizonlive.com

iMovie: desktop movie production for Apple computers. www.apple.com/imovie

Interactive Videoconferencing in Distance Education www.uidaho.edu/evo/dist10.html

NetMeeting: how to get started. www.microsoft.com/windows/netmeeting

Newbie Guide to Videoconferencingnetconference.about.com/internet/netconference/library/weekly/aa030700a.htm

Research Channel www.researchchannel.org

Star Schools: Engaged Learning Project. www.starschools.org/webcast/archived/el

Streaming Media 101: introduction to streaming media.

http://desktopvideo.about.com/compute/desktopvideo/library/weekly/aa061901a.htm



http://www.col.org/



http://developer.apple.com/quicktime/qttutorial

http://astdppu.webex.com/

http://gsh.lightspan.com/cu

http://www.col.org/videos/videos.htm

http://www.utexas.edu/cc/cit/streaming

http://www.cuworld.com/

http://www.gwu.edu/gelman/ref/readyref/news.html

http://www.apple.com/education/dv

http://desktopvideo.about.com/compute/desktopvideo

http://www.fvc.com/eng/webconferencing



http://www.uidaho.edu/evo/dist10.html

http://www.microsoft.com/windows/netmeeting

http://netconference.about.com/internet/netconference/library/weekly/aa030700a.htm

http://www.researchchannel.org/

http://www.starschools.org/webcast/archived/el




http://www.col.org/



http://developer.apple.com/quicktime/qttutorial

http://astdppu.webex.com/

http://gsh.lightspan.com/cu

http://www.col.org/videos/videos.htm

http://www.utexas.edu/cc/cit/streaming

http://www.cuworld.com/

http://www.gwu.edu/gelman/ref/readyref/news.html

http://www.apple.com/education/dv

http://desktopvideo.about.com/compute/desktopvideo

http://www.fvc.com/eng/webconferencing



http://www.uidaho.edu/evo/dist10.html

http://www.microsoft.com/windows/netmeeting

http://netconference.about.com/internet/netconference/library/weekly/aa030700a.htm

http://www.researchchannel.org/

http://www.starschools.org/webcast/archived/el



www.zdnet.com/devhead/stories/articles/0,4413,2703779,00.html

Streaming Media World: streaming video articles and resources.www.streamingmediaworld.com

ViewCast: an inexpensive video capture card that integrates video editing,compression and encoding and a downloadable guide to video streaming.www.viewcast.com/viewcast.html

WebEx: learning delivery platform with streaming. www.webex.com

WinProducer: Windows video authoring software. www.intervideo.com

Your Video on the Web: step-by-step streaming video instructions.yourvideoontheweb.com

RESEARCHED AND WRITTEN BYLINDA STILBORNE, LEARNING TECHNOLOGY CONSULTANT, OTTAWA, CANADA

PETER MACGIBBON, HERITAGE COLLEGE, QUÉBEC, CANADA

© The Commonwealth of Learning, 2001. This publication may be reproduced for non-commercial purposes.Acknowledgement to The Commonwealth of Learning and the author must be retained.

COL is an intergovernmental organisation created by Commonwealth Heads of Government to encourage the developmentand sharing of open learning and distance education knowledge, resources and technologies.

The Commonwealth of Learning, Suite 600 - 1285 West Broadway, Vancouver, BC V6H 3X8 CANADAPH: +1.604.775.8200 | FAX: +1.604.775.8210 | EMAIL: [email protected] | www.col.org

http://www.zdnet.com/devhead/stories/articles/0,4413,2703779,00.html

http://www.streamingmediaworld.com/

http://www.viewcast.com/viewcast.html


http://www.intervideo.com/

http://yourvideoontheweb.com/

mailto:[email protected]

http://www.col.org/

http://www.col.org/

http://www.zdnet.com/devhead/stories/articles/0,4413,2703779,00.html

http://www.streamingmediaworld.com/

http://www.viewcast.com/viewcast.html


http://www.intervideo.com/

http://yourvideoontheweb.com/

mailto:[email protected]

http://www.col.org/

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