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.
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. Therefore 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.
- 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.
- 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.
- Missing or inadequate transcripts
Videos which do not have a transcript or have inadequate transcripts greatly affect the users who rely on the transcript to obtain the information.
- 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.
Transcripts are sometimes provided, however the transcripts may be inaccessible because they have been provided as a PDF. A PDF is extremely 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.
- Missing audio transcripts.
Videos which do not include audio descriptions leave a vision impaired user with less information about the video than those who don’t have the use of audio descriptions. Important background information may be provided in the video that isn’t conveyed with audio.