Curriculum Corporation
Video Research Project

The end of the tape?
Video programs are traditionally distributed on videotape. Programs shot and edited digitally can still be distributed using this analogue format. Small numbers of VHS cassettes can be duplicated at school. Also, you can find local video production companies with bulk duplication facilities in most communities.

Distribution of Video

Useful background whitepapers

Key concepts

  • New video technologies have made the medium more accessible and enabled video to be more broadly incorporated into the curriculum.
  • School and classroom video projects can be delivered on CD, DVD, online or videotape.
  • The choice of delivery method involves trade-offs between cost and convenience, and requires consideration of the nature of the content and the audience.

Introduction

The historically high cost of video production equipment has tended to limit its use in schools.

The introduction of Digital Video ({glossary:dv}DV{~glossary}) cameras and computer-based editing systems has transformed both the business of video and television production and the accessibility of high-quality video production to individuals and households. Technological change has also introduced new distribution opportunities, ranging from the superb quality of {glossary:dvd}DVD{~glossary} to the immediacy and reach of the web.

These technologically driven developments have the potential to positively impact schools, offering students and teachers the opportunity to work with this powerful medium in new ways and in new subject areas, and to share the results of their creative endeavours with unprecedented ease.

Creating DVD

The {glossary:dvd}DVD{~glossary} format offers convenience and high-quality playback for those users with a {glossary:dvd}DVD{~glossary} player or a computer with a {glossary:dvd}DVD{~glossary} drive. The cost of blank {glossary:dvd}DVD{~glossary} media continues to fall. Blank recordable {glossary:dvdr}DVD-R{~glossary} ({glossary:dvd}DVD{~glossary}-Recordable) media is available for under a dollar. Commercial replication of DVDs is available and becomes cost effective if done in larger numbers.

A cheaper alternative to {glossary:dvd}DVD{~glossary} that is still compatible with most {glossary:dvd}DVD{~glossary} players is the Video CD. Video CD is a format popular in Asia for the distribution of movies on CD. It predates {glossary:dvd}DVD{~glossary} and uses the MPEG-1 video {glossary:compression}Compression{~glossary} format. MPEG-1 was the first MPEG video format developed by the Motion Picture Experts Group. The higher quality (and higher {glossary:datarate}Data Rate{~glossary}) MPEG-2 format is used on {glossary:dvd}DVD{~glossary}.

If you create a {glossary:videocd}Video CD{~glossary}, keep in mind that some older {glossary:dvd}DVD{~glossary} players may be unable to playback recordable ({glossary:cdr}CD-R{~glossary}) or rewriteable ({glossary:cdrw}CD-RW{~glossary}) discs. It pays to keep your audience in mind and undertake testing if practical.

CD-ROM video playback

The {glossary:dvd}DVD{~glossary} format is highly standardised to ensure that {glossary:dvd}DVD{~glossary} discs will play back on {glossary:dvd}DVD{~glossary} players from any manufacturer. However, if the digital video files you are creating are destined for playback on a computer, perhaps as components of a larger interactive multimedia program, then there is less standardisation and a greater choice of formats.

These formats include {glossary:windowsmedia}Windows Media{~glossary}, {glossary:realvideo}Real Video{~glossary} and {glossary:quicktime}QuickTime{~glossary}, with each format requiring its own separate player. The {glossary:mpeg4}MPEG-4{~glossary} format, discussed below in the online distribution section, can also be distributed on CD-ROM.

The older MPEG-1 format is not particularly compact, it too can be placed on a {glossary:cdrom}CD-ROM{~glossary} and played back within both the {glossary:quicktime}QuickTime{~glossary} and {glossary:windowsmedia}Windows Media{~glossary} players, even on relatively old Macintosh and PC computers, an important consideration in schools.

Hardware and software

The cost of CD and {glossary:dvd}DVD{~glossary} burners has declined rapidly and they are now built into most new computers.

{glossary:dvd}DVD{~glossary} discs must be authored to conform to the strict international standards discussed above. Until recently, this has required the use of expensive {glossary:dvd}DVD{~glossary} {glossary:authoring}Authoring{~glossary} software. Today, basic {glossary:dvd}DVD{~glossary} {glossary:authoring}Authoring{~glossary} software is usually pre-installed on computers equipped with {glossary:dvd}DVD{~glossary} burners or is included when a separate {glossary:dvd}DVD{~glossary} writer is purchased. Your computer may have a dual, or double, layered {glossary:dvd}DVD{~glossary} burner or even be able to burn {glossary:dvd}DVD{~glossary}+R discs. Bear in mind that these may not play on all home players, so if you are {glossary:authoring}Authoring{~glossary} to this medium, always test your disc on a number of players.

Capacity of disc media

A CD has a capacity of over 600MB ({glossary:megabyte}megabytes{~glossary}) which is sufficient to store around one hour of low-quality full-screen {glossary:MPEG-1}mpeg1{~glossary} video.

{glossary:dvdr}DVD-R{~glossary} and the rewriteable {glossary:dvdrW}DVD-RW{~glossary} format discs currently have a capacity of 4.7GB {glossary:gigabyte}Gigabytes{~glossary}), allowing up to an hour of MPEG-2 format video, depending on the quality level/{glossary:datarate}Data Rate{~glossary} being used. Commercial mass-produced DVDs, which can be both double sided and double layered, provide sufficient space to store feature-length movies of several hours duration.

Online distribution

Figure 1: Screengrab of a QuickTime web video
Figure 1 Screengrab of a QuickTime web video

Direct electronic transfer of digital video to end users via the Internet presents an exciting opportunity for teachers and students to distribute their video programs. Student work can be shown in virtual exhibitions, guest speakers and one-off PD can be captured and distributed, and distance students can experience classroom and school activities.

Uncompressed digital video files are large but they can be compressed (see the Video {glossary:compression}Compression{~glossary} whitepaper) for online distribution.

Web video clips can still be very compelling even when they occupy only a small part of the screen as shown in Figure 1. At this size (around 180 {glossary:pixel}pixels{~glossary} wide by 120 {glossary:pixel}pixels{~glossary} high), a clip can be downloaded surprisingly quickly, even by users on {glossary:dialup}dialup{~glossary} Internet connections.

Video editing programs can export clips in one or more of the popular web {glossary:compression}Compression{~glossary} formats such as {glossary:quicktime}QuickTime{~glossary} or {glossary:windowsmedia}Windows Media{~glossary} (which need software that can read their formats installed on your computer). Specialised {glossary:compression}Compression{~glossary} software gives even more control over the process for those seeking higher quality or who need to create lots of different clips. An example of needing software to view videos online is this website. If you don't have the {glossary:quicktime}QuickTime{~glossary} plugin or player, you will not be able to view the video content presented here.

Deciding which video format to select is often difficult because of the variety of formats available and their lack of compatibility with each other. In the school environment, users themselves are generally not permitted to install new software. This limits your choice of video formats to those that your end users are already set up to play.

The Motion Picture Experts Group has also developed a new standard called MPEG-4. This standard is supported by some players, and has the potential to bring the benefits of standardisation to the web that came with the MPEG-1 and MPEG-2 formats.

If your video is available in several different formats and perhaps at different sizes, the likelihood that it will be viewed is maximised, regardless of the type of computer being used or the speed of the user’s network connection. Users can then choose a clip of a size and format appropriate to their circumstances.

Figure 2 illustrates how these choices might be presented to users.

Figure 2: Table of various web video formats and their corresponding file sizes
Figure 2Table of various web video formats and their corresponding file sizes

Planning for online distribution of large and potentially popular files should always be discussed with the IT administrator.