Success Criterion 1.2.5 - Level AA

Audio Description (Prerecorded)

Ensure audio description is available when important information is shown which you cannot hear. This can be done by offering an extra audio track. This allows people who are blind or have difficulty processing visual information to also understand the content.

Impact

People who are blind cannot perceive visual information from videos, audio description provides this information for them.
It can be difficult for people with cognitive disabilities to understand what is being shown in videos.

Check

“Are visual details in videos described?”

This can be tested visually, no assistive technologies are needed.

Solution

Add audio description

As of Android 4.1, the MediaPlayer has support for multiple audio tracks. Use the selectTrack method to select the correct audio track.

The code example belows shows a basic implementation of selecting an audio description track embedded inside a video.

Kotlin

val player = MediaPlayer.create(this, R.raw.video)
try {
    player.trackInfo.forEachIndexed { index, trackInfo ->
        if (trackInfo.trackType == TrackInfo.MEDIA_TRACK_TYPE_AUDIO) {
            player.selectTrack(index)
            return@forEachIndexed
        }
    }
    player.start()
} catch (e: Exception) {
    e.printStackTrace()
}