# Providing audio description in SMIL 2.0

ID: SM7

Technology: smil

Type: Technique

## When to Use

Applies whenever SMIL 2.0 player is available

## 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

### SMIL 2.0 audio description sample for RealMedia player

    <smil xmlns="https://www.w3.org/2001/SMIL20/Language">
    <head>
      <layout>
        <root-layout backgroundColor="black" height="266" width="320"/>
        <region id="video" backgroundColor="black" top="26" left="0"
         height="144" width="320"/>
      </layout>
      </head>
      <body>
        <par>
          <video src="salesdemo.mpg" region="video" title="Sales Demo"
          alt="Sales Demo"/>
          <audio src="salesdemo_ad.mp3" begin="33.71s" title="audio description"
          alt="Sales Demo Audio Description"/>
        </par>
      </body>
    </smil>

The example shows a `par` segment containing an `audio` and a `video` tag. The audio stream is not started immediately.

## 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

## Related Techniques

- SM2
- SM6

## Resources

- Synchronized Multimedia Integration Language (SMIL 2.0)
- Synchronized Multimedia Integration Language (SMIL 3.0)
- Accessibility Features of SMIL