Techniques for WCAG 2.0

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# SM6: Providing audio description in SMIL 1.0

## Applicability

Applies whenever SMIL 1.0 player is available

This technique relates to:

- Success Criterion 1.2.3 (Audio Description or Media Alternative (Prerecorded))
  - How to Meet 1.2.3 (Audio Description or Media Alternative (Prerecorded))
  - Understanding Success Criterion 1.2.3 (Audio Description or Media Alternative (Prerecorded))

## Description

The objective of this technique is to provide a way for people who are blind or otherwise have trouble seeing the video in audio-visual material to be able to access the material. With this technique a description of the video is provided via audio description that will fit into the gaps in the dialogue in the audio-visual material.

## Examples

### Example 1: SMIL 1.0 audio description sample for QuickTime player

Example Code:

    <?xml version="1.0" encoding="UTF-8"?>
    <smil xmlns:qt="http://www.apple.com/quicktime/resources/smilextensions"
      xmlns="http://www.w3.org/TR/REC-smil" qt:time-slider="true">
      <head>
        <layout>
          <root-layout background-color="black" height="266" width="320"/>
          <region id="videoregion" background-color="black" top="26" left="0"
          height="144" width="320"/>
        </layout>
      </head>
      <body>
        <par>
          <video dur="0:01:20.00" region="videoregion" src="salesdemo.mov"
          alt="Sales Demo"/>
          <audio dur="0:01:20.00" src="salesdemo_ad.mp3"
          alt="Sales Demo Audio Description"/>
        </par>
      </body>
    </smil>

### Example 2: SMIL 1.0 audio description sample for RealTime player

Example Code:

    <?xml version="1.0" encoding="UTF-8"?>
    <smil xmlns="http://www.w3.org/TR/REC-smil">
      <head>
        <layout>
          <root-layout background-color="black" height="266" width="320"/>
          <region id="videoregion" background-color="black" top="26" left="0"
          height="144" width="320"/>
        </layout>
      </head>
      <body>
        <par>
          <video src="salesdemo.mov" region="videoregion" title="Sales Demo"
          alt="Sales Demo"/>
          <audio src="salesdemo_ad.mp3" title="audio description"
          alt="Sales Demo Audio Description"/>
        </par>
      </body>
    </smil>

## Resources

Resources are for information purposes only, no endorsement implied.

- Synchronized Multimedia Integration Language (SMIL) 1.0

- Synchronized Multimedia Integration Language (SMIL 2.0)

- Accessibility Features of SMIL

- NCAM Rich Media Accessibility, Accessible SMIL Templates

- Realtext

- SAMI 1.0

- Accessibility Features of SMIL

## Related Techniques

- SM2: Adding extended audio description in SMIL 2.0
- SM7: Providing audio description in SMIL 2.0

## Tests

### Procedure

1. Find method for turning on audio description from content/player (unless it is always played by default)

2. Play file with audio description

3. Check whether audio description is played

### Expected Results

- #3 is true

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