Skills for Access

Why this is important

For people with low vision, colour deficit or difficulties reading on-screen text, some content of a media clip may be hard to read, particularly if the size of screen area showing the media clip is small. People who are hard-of-hearing and who also have sight problems may also have difficulty reading captions presented in a small text size, or specific font or colour combination.

General Principles

The guiding principle here is to allow users to make necessary adjustments to the display of a media clip to suit their own needs. For example, if a user needs to enlarge the display of a media clip in order to see the content, this should be made possible, most easily by making media content available via a standalone player. Where captions are available, it should be possible for users to configure the display of these (for example language, location, size or colour).

Before you continue

The advice on this page helps you avoid introducing a specific accessibility barrier, but it's not a magic formula. To avoid attempting to follow a technical solution that is not appropriate to the resource and its intended purpose, you need to know the context in which the multimedia resource is being used:

1. The purpose or aim of the multimedia resource in question, and whether it is being used to supplement another resource in the learning environment, or whether its use is required by students.
2. The target audience, their knowledge and expectations, and the type of browsing and assistive technology that they may be using.
3. Whether the information and experiences provided by the multimedia technology are already available in an equivalent, alternative form.

For more background on this approach, see our Guide to the use of multimedia in accessible e-learning.

Technique Details

In practice, the steps an author can take to enable user-customisation of media content are limited. Stand-alone media players allow a reasonable degree of resizing options, so for example when the media player display is enlarged, the caption text is also enlarged. Without screen magnification software or hardware, embedded media is fixed in terms of size.

Media players offer little scope in terms of allowing customisation of caption text display. Some methods of providing captions, such as SMIL, use Cascading Style Sheets to provide style information for the caption text. This means that a user can in theory intervene to enable captions to be displayed according to their own needs, by changing position, size, font, colour or background colour - this is one of the guiding principles of the SMIL specification and accessibility features. In practice though, it seems that due to player limitations and comparative immaturity of the technology, examples of this in practice are extremely hard to find.

It is hoped that as technologies mature, so too will techniques for their implementation.

Testing

Given the current state of the art, testing of a media player's customisability may be limited. However, it's certainly worth making sure that captions display appropriately when the media player in question is enlarged. Examples of how to do this:

• Real Player 10 allows options for "Double Size" and "Full Screen Theater", both of which appear to enlarge caption text. Select "View" then "Zoom" to access these options or use the keyboard shortcuts CTRL+1, CTRL+2 and CTRL+3 to select normal, double size and full screen theater respectively). .

• QuickTime Player 6 includes a "Double Size" option (in the "Movie" menu, or use the keyboard shortcuts CTRL+2 and CTRL+1 to select double size and normal size respectively). Caption text should be enlarged accordingly.

• With Windows Media Player 9, in Full Mode, there are options to enlarge the window containing the video to twice the default size (Video Size - 200%, or keyboard shortcut ALT+3) or to Full Screen size. But in neither case does caption text appear to be enlarged. Furthermore, it appears that even when they are set to display when provided, captions may not be shown when Skins Mode is chosen.