Audio description via VTT track, read by screen readers

This demo uses WebVTT files to deliver text-based audio description. WebVTT description tracks are available in multiple languages, which correspond with the subtitle languages. If the user switches the subtitle language via the Captions button, the description language will change as well.

If Description is toggled on, description text will be exposed to screen readers in an ARIA live region. This differs from Audio Description Demo #1, which uses the Web Speech API to read the description text. The latter is preferable when browsers support it, but if they don't, the ARIA live region method is used as a fallback. By setting data-desc-reader="screenreader", Able Player uses the ARIA live region method by default. This is generally discouraged, but might be preferable for websites in languages where few if any voices are available through the Web Speech API.