Audio Descriptions

Adds support for native text-to-speech audio descriptions for videos.

This extension adds support for audio descriptions in videos that use the track element. A drop down menu field is appended after compatible videos for users to enable audio description tracks. When a audio description track is enabled and a video is playing, when a cue is reached, the video is paused, the audio description text is read aloud via text-to-speech, then the video is played again. There are settings in the extension's popup for adjusting the text-to-speech rate and pitch. Many more features in the future.