Audio Description or Media Alternative (Prerecorded)

[ecureuill]

1.2.3

Dev Tasks

AUTHORING TOOL

• [x] Give teacher the option to upload an audio description as a .vtt file or a alternative audio track (in Audio Description tab)
• [ ] [media alternative] Give teacher the option to inform a transcription (in Text Alternative tab) This approach involves providing all of the information in the synchronized media (both visual and auditory) in text form. An alternative for time-based media provides a running description of all that is going on in the synchronized media content.

STUDENT MODULE

• [x] Render video with the above resources using techniques in #159

Sufficient techniques

G78: Providing a second, user-selectable, audio track that includes audio descriptions

The objective of this technique is to provide an audio (spoken) version of information that is provided visually so that it is possible for people who cannot see to be able to understand audio-visual material.

Example

1. A travelogue of the northeast has additional audio description added during the gaps in the dialogue to let listeners who are blind know what the person is talking about at any point in time.
2. A video shows a woodpecker carving a nest in a tree. A button within the content allows users to turn the audio description track on or off.
3. A lecture has audio description added whenever the instructor says things like "and this is the one that is most important." The audio descriptions lets listeners who can not see the video know what "this" is.
4. A movie file has two audio tracks, one of which includes audio description. Users can choose either one when listening to the movie by selecting the appropriate track in their media player.

Test Procedure

1. Check that the ability exists to turn on the audio track that includes audio descriptions. For example, by using a control within the content itself or by selecting a control or preference in the media player or operating system.
2. Listen to the synchronized media
3. Check to see if gaps in dialogue are used to convey important information regarding visual content

Expected Results

Checks # 1 and # 3 are true.

G173: Providing a version of a movie with audio descriptions Using any player that supports audio and video

The objective of this technique is to provide a second version of video content that provides audio desciptions so that it is possible for people who cannot see to be able to understand audio-visual material.

Example

1. Two versions of a video of an opera are available. The first version includes only the music. The second version includes both the music and voice describing the actions of the performers on stage.
2. A video of juggler performing in front of group of children includes a version with audio description. The narrator of the audio description describes the number and type of items the juggler is juggling as well as the reactions the children have during the performance.

Test Procedure

1. Open the version of the media that includes audio description.
2. Listen to the movie.
3. Check to see if gaps in dialogue are used to convey important information regarding visual content.
4. If the alternate version(s) are on a separate page, check for the availability of link(s) to allow the user to get to the other versions.

Expected Results

Checks # 3 and # 4 are true.

G8: Providing a movie with extended audio descriptions Using any player that supports audio and video

The objective of this technique is to provide a second version of video content that provides extended audio descriptions. One of the difficult things about creating traditional audio descriptions is that the narrator sometimes has to provide a lot of information during very short pauses in dialogue. Extended audio description temporarily pauses the audio and video to allow critical information to be delivered when pauses in dialogue are insufficient for adequate description.

Example

1. An alternate version of an online video of a family escaping from a burning building: there is a continuous dialogue between the husband and wife about where the children are. Meanwhile, in the background, a wall caves in. This is important information in the story because it will block their exit from that part of the building. The video track halts (same frame is repeated) while a narrator gives the details about the wall falling and the video continues.
2. A training film has narrative that runs almost continuously throughout. An alternate version is available for people who have difficulty viewing the video portion. The alternate version freezes the video and provides audio description of key information.

Test Procedure

1. Open the version of the movie that includes extended audio descriptions.
2. Check that the video halts for extended audio description when there is not enough space to include necessary narration between the natural dialogue.
3. Check that the necessary information is in the audio description.
4. If the alternate version(s) are on a separate page, check for the availability of link(s) to allow the user to get to the other versions.

Expected Results

Checks # 2, # 3 and # 4 are true.

G203: Using a static text alternative to describe a talking head video

The purpose of this technique is to provide an alternative to audio description (...) This particularly applies to "talking head" videos where a person is talking in front of an unchanging background, such as a press conference, company president talk, or government announcement, etc. In this case there are no "important visual details" which would warrant audio description.

Example

1. A video of a CEO speaking to shareholders A CEO is speaking to shareholders from his office. The video has a title page at the beginning of the video giving the date. When the speaker begins, there is a strip of text at the bottom of the video saying "John Doe, President of XYZ Cooperation". At the end of the video are title credits that say "produced by the Honest TV Productions Ltd." As an alternative, there is a paragraph below the video which is associated with the video file using aria-describedby which says: "July 22, 2011, John Doe, President of XYZ cooperation, speaking from his office. Video produced by the Honest TV Productions Ltd."

Test Procedure

1. Check that there is no important time-based information in the video track
2. Check that the programmatically associated description of the media contains any context of the content that is not contained in the audio track (e.g. speaker identification, credits, context)

Expected Results

All checks are true.

Advisory Techniques

Advisory techniques are suggested ways to improve accessibility. They are often very helpful to some users, and may be the only way that some users can access some types of content. Advisory techniques are not designated as sufficient techniques for various reasons such as:

• they may not be sufficient to meet the full requirements of the success criteria;
• they may be based on technology that is not yet stable;
• they may not be accessibility supported in many cases (for example, assistive technologies do not work with them yet);
• they may not be testable;
• in some circumstances they may not be applicable or practical, and may even decrease accessibility for some users while increasing it for others;
• they may not address the success criterion itself, and instead provide related accessibility benefits. Authors are encouraged to apply all of the techniques where appropriate to best address the widest range of users' needs.

H96: Using the track element to provide audio descriptions

use the HTML5 track element to specify a descriptions timed text track for a video element. Audio description timed text tracks contain textual descriptions of the video component of the media resource, intended for audio synthesis when the visual component is obscured, unavailable, or not usable.

:exclamation: IMPLEMENTATION ALERT As of February 2019 when this Advisory technique was last reviewed by the Working Group, there is no native support in user agents for this technique. However, support is available via JavaScript polyfills.

Example

<video poster="myvideo.png" controls>
  <source src="myvideo.mp4" srclang="en" type="video/mp4">
  <source src="myvideo.webm" srclang="fr" type="video/webm">
  <track src="myvideo_en.vtt" kind="descriptions" srclang="en" label="English">
  <track src="myvideo_fr.vtt" kind="descriptions" srclang="fr" label="French">
</video>   

Test Procedure

For each video element used to play a video:

1. Check that the video contains a track element of kind descriptions in the language of the video.

Expected Results

Check # 1 is true.

Resources

For G78

• HTML5 multi-track audio or video
• Codepen.io Example
• Howler.js

Referenced Requirements

:notebook_with_decorative_cover: References

• How to Meet WCAG (Quick Reference)
• Understanding Techniques for WCAG Success Criteria

GLOSSARY

• SELI's content: all contents not created by users (e.g. seli "about" section text)

:warning: The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119/8174.

1. MUST This word, or the terms "REQUIRED" or "SHALL", mean that the definition is an absolute requirement of the specification.
2. MUST NOT This phrase, or the phrase "SHALL NOT", mean that the definition is an absolute prohibition of the specification.
3. SHOULD This word, or the adjective "RECOMMENDED", mean that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course.
4. SHOULD NOT This phrase, or the phrase "NOT RECOMMENDED" mean that there may exist valid reasons in particular circumstances when the particular behavior is acceptable or even useful, but the full implications should be understood and the case carefully weighed before implementing any behavior described with this label.
5. MAY This word, or the adjective "OPTIONAL", mean that an item is truly optional. An implementation which does not include a particular option MUST be prepared to interoperate with another implementation which does include the option, though perhaps with reduced functionality. In the same vein an implementation which does include a particular option MUST be prepared to interoperate with another implementation which does not include the option (except, of course, for the feature the option provides.)

[ecureuill]

@solex2006 As in #9 , teachers could benefit from a more flexible approach See comment

[github-actions[bot]]

This Feature is ready to be implemented.

[github-actions[bot]]

This Feature is ready to be implemented.

[ecureuill]

Failures

• [ ] due to not give teacher the option to upload an "audio description" in (.vtt) file Give teacher the option to upload an audio description file (.vtt) OR an alternative audio track (audio file)