Making Small Video Files for Courses

Tom Worthington FACS CP

Adjunct Lecturer, Australian National University

For the Flipped Classroom Professional Development Session, Canberra Institute of Technology, Room A22, Bruce Campus, Canberra, 26 July 2012

Tom Worthington was awarded a certificate in audio-visual production for training, by the then ACT TAFE in 1990. He decided it was time to apply some of those skills to teaching. Tom discusses how to make a video file smaller, so it downloads quicker for students and takes up less space on the educational institution's server.

Recording a Screen-Cast

On Linux:

recordMyDesktop to record.

WinFF to convert to WebM format for YouTube.

Video Resolution

High-definition television (HDTV) formats supported by YouTube:

720p (1280 × 720 progressive scan)

1080p (1920 × 1080 progressive scan)

But lower the frame rate from the usual 24 frames per second for screen-casts

Video and Audio

The web supports a wide range of audio and video formats
ANU Digital Lecture Delivery System (DLD) supports (typical file size):
- Audio: MP3 Mono 16,000Hz 0.2 Mbytes per minute
- MP4 432 x 320 Pixel 5 Frames Per second "iPod" Video 1 Mbytes per minute
- MP4 1024 x 768 Pixels 2 Frames per second "Computer" Video 3.5 Mbytes per minute
Animation for smaller easier to understand video: Airport.

The web supports a wide range of audio and video formats. Audio and video files can be simply added to course web sites, or uploaded to a learning management system.

The ANU Digital Lecture Delivery System (DLD) supports (typical file size): MP3 Audio and MP4 Video at "iPod" low resolution and "Computer" high resolutions.

The video provided by the DLD is intended for displaying slides with limited movement, not full motion video. Before including full motion video, consider if it is really needed and how much is needed. Videos of lectures should not be more than 10 to 20 minutes, to keep them interesting. Intersperse "talking heads" with slides.

Animation

Low resolution limited colour moving images (animation) with audio can be used to good effect for education. These are technically efficient and also easy understand, as they remove unnecessary detail from the images. An example of animation is the award winning Airport by Iain Anderson (2005), made just using the signs found at airports.

Provide Alternatives for Accessibility

Web Accessibility helps with disabilities, mobile users and student understanding generally
Key idea: Provide alternatives: Text captions on images, text descriptions, captions for video, audio and images as an alternative to full motion video.
The web supports alternative text for images
See the Web Content Accessibility Guidelines (WCAG) for details of accessible web design.
Since the SOCOG 2000 Case, web accessibility has been required by Australian law.
Educational institutions are required to make web based course materials accessible, wherever feasible

The web supports alternative text for images. The key point is to provide information in alternative formats, for people who cannot see, or who have devices which cannot display some formats. In this case provide a text caption for people who can see an image, or a using a device which cannot display an image.

The Web Content Accessibility Guidelines (WCAG), produced by the World Wide Web Consortium (W3C) are a widely accepted guide to web accessibility. The guidelines help with the design and testing of web pages for people who have a disability (such as limited vision), as well as web pages for use on for mobile devices.

Since the SOCOG 2000 Case, web accessibility has been required by Australian law. Australian universities are subject to this legislation and are required to make web pages accessible, wherever possible. It is not lawful to simply wait until a student with a disability enrols in a course and then look at making the course website accessible: this must be done in advance.