Overview
On this page
- Video training manual
- Video accessibility principles
- Impact on users
- Video checklist
- Start Learning Transcripts!
Video training manual
Video accessibility principles
Video accessibility is the ability for a person with a disability to understand and use an online video. It allows people with disabilities to access information like anyone else; interact with others without being classed as “disabled” and allows them to undertake activities which they may not otherwise be able to do.
Video accessibility is important to people with the following disabilities:
- Blindness
- Colour-blindness
- Low vision
- Deafness
- Motor impairments
- Cognitive impairments.
Videos cannot be made fully accessible, but they can be made accessible to most people with disabilities; for example people using screen readers. A video is made accessible by:
- the way the video is created;
- how the video is inserted in the site;
- by providing a transcript;
- by providing audio descriptions; and
- by providing captions.
OzPlayer is the first completely accessible video player.
Accessibility needs to be considered both when creating the video content and when converting the video for web use.
When creating the video content:
- use only high contrast colours;
- do not convey information using colour alone;
- do not use patterned backgrounds etc.; and
- do not include any flashing or flickering content.
When converting the video for web use:
- use a consistent, accessible, video file format.
When inserting the video in the site in a particular way:
- Allow the user to skip over the video using the mouse only;
- Allow the user to skip over the video using the keyboard only;
- Ensure the site is functional and all content is available without the video; and
- Include information about how to access the video player.
WCAG2 requirements
To meet WCAG2 Level AA requirements, a video must:
- Have an equivalent alternative for all important auditory and visual content is provided
- The equivalent alternatives that must be included are:
- synchronised captions
- a synchronised audio description
- A transcript can be thought of as a combination of the captions and the audio description
- Provision of a separate text (HTML) transcript is recommended but is not a strict WCAG level AA requirement
At level A, captions are required as well as either a text alternative (transcript) or audio descriptions. Having both captions and audio descriptions is considered the same as having a transcript as it provides the same information. However, it is recommended a transcript is always provided.
Video player
According to the W3C Web Content Accessibility Guidelines, Version 2.0, Level AA the video player should:
- Adequate keyboard access
- The video player must have the ability to operate the video controls with the keyboard
- The video controls must have a highly visible keyboard focus indicator
- The video player must not contain a keyboard trap.
- Sufficient control and operation
- The video player must not start automatically when the page opens
- The video player must allow the volume to be controlled independently of the system volume.
- Correct implementation
- An equivalent alternative must be provided
Currently OzPlayer is the only video player which meets all these requirements on all operating systems.
Transcript
Video transcripts should:
- Identify the name of the speaker;
- Ensure that all speech content is included;
- Include relevant information about the speech;
- Include relevant non-speech audio;
- Include any textual or graphical information shown in the video;
- Be provided in an accessible format;
- Indicate the end of the transcript if on the same page as the video; and
- Provide a mechanism to return to the video if on another page.
Captions
Video captions should:
- Appear at the same time as the sound they are captioning;
- Ensure all important audio information has been captured;
- Appear on the screen for enough time for them to be read;
- Ensure the contrast between background and caption text colour is sufficient;
- Have no periods without captions; and
- Attribute speech to a particular speaker.
Audio Descriptions
It should be noted that audio descriptions are best done when creating the video as an alternative to the original video.
Video audio descriptions should:
- Adequately describe the visual information;
- Not impinge on other speech or important sounds;
- Be concise but sufficiently explanatory; and
- Be sufficiently distinguishable from other speech.
Impact on users
The following is an overview of common video errors relevant to the player, captions, transcripts and audio descriptions and the impact on users with a disability.
Video Player
Keyboard.
Some video players contain keyboard traps. This is critical to users who are unable to use the mouse as there is no way to exit the video player once caught in a keyboard trap. The only option is to close the browser and start again.
Some video players do not have the ability to use the video via the keyboard. This limits the video use to mouse users only.
Starting, stopping and controlling volume.
Some video players will automatically start when a page opens and there may not be a website mechanism to pause or stop the video. Where a mechanism has been provided to pause the video, screen reader users and keyboard users have to manually search through the page until they find the video and stop it using the player controls.
Flash, JavaScript and style sheets.
Disabling browser functions can cause the video to disappear, move or appear actionable when it isn’t. Screen reader users will sometimes disable certain browser functions, e.g. JavaScript, to facilitate use of their assistive technology.
Content changes.
In some instances selecting the video will cause a change prior to the current focus. If a user is visually impaired and uses a screen reader, this change may not be apparent to the user.
Video link text.
Some links to video files can be non-descriptive and use file size, filename or file type. For users with assistive technologies such as screen readers, it can be difficult to know what the video is about, especially if there is more than one video.
Video as a text alternative.
On some occasions videos are provided as an alternative to text and images. In these instances, the video needs to be labelled as a text alternative so that users know what the purpose of the video is and that it is not the main source of the content.
Flashing video content
Videos with flashing content which flashes more than three times in any one second period can induce seizures in users with photosensitive seizure disorder. It can also trigger migraines in sensitive users.
Transcript
Missing or inadequate transcripts.
For a number of different reasons there will be users who are unable to play the video. For these people transcripts are absolutely essential.
Additional information.
The transcript sometimes includes information that is not included in the video. Users who are able to access the video and do not use the transcript will therefore miss this additional information.
Accessibility.
Transcripts are sometimes provided, however the transcripts may be inaccessible because they have been provided as a PDF. A PDF is inaccessible even when tagged and many screen reader users will not even attempt to read one.
Location and link text.
Transcripts are sometimes provided but the link to it is not located immediately before or after the video. A screen reader user will then often assume there isn’t a transcript provided and move on without obtaining the information from the video.
Similarly, a user may assume that there isn’t a transcript provided if the link text to the transcript is not clear.
End of transcript.
If the transcript is on the same page as the video, it will affect users if the end of the transcript is not marked. Screen reader users will not know that the transcript has finished as the assistive technology will continue on reading page content without indicating an end to the transcript.
Returning to the video.
When the transcript is provided on a separate page to the video, some transcripts provide no method of returning back to the original video. Some users may find it difficult to find their way back to where they were without a link or the use of the back button.
Interactive transcripts.
Interactive transcripts should keep track with the video content to minimise confusion to those with cognitive issues. The current position in the interactive transcript should not be marked with colour alone which can affect vision impaired users and those who use assistive technologies.
Captions
Missing or inadequate captions.
In some instances videos do not include captions or omit dialogue or important sound effects. Those who use captions will be unable to use the video or may miss out on important information.
Additional information.
Video captions sometimes include information that is not included in the video. Users who don’t have a need for the captions will therefore miss this information.
Colour contrast.
The captions can be difficult to read due to colour contrast between the background and the caption colour. Users dependent on the captions may therefore not be able to read important information conveyed by the captions.
Audio description
Missing audio descriptions.
Videos which do not include audio descriptions means a vision impaired user will miss important information. Important background information may be provided in the video that isn’t conveyed with audio.
Video checklist
See the online video checklist on the AccessibilityOz wiki.
Start Learning Transcripts!
Time to get stuck into the video walkthroughs. First up is creating transcripts.