Block 8. Accessibility and Scale

What WCAG 2.1 AA requires for learning video: captions, audio description, an accessible player, and the ADA, Section 508, and EU deadlines you must meet.

Closed vs open captions, plus transcripts and audio description for learning video: what to produce, how accurate it must be, and what it costs.

Deliver a course in many languages at scale: subtitles vs dubbing, multi-track video, BCP 47 tags, right-to-left, and keeping every locale in sync.

Deliver learning video on slow, costly, or unreliable networks: adaptive bitrate, low-bandwidth live modes, offline download, and the right codec floor.

Build learning video phone-first: a portrait touch player, vertical micro-lessons, Wi-Fi-only download, background audio, offline xAPI tracking, and WCAG.

How offline learning really works: packaging courses for the device, deferred xAPI sync, SCORM and cmi5 offline limits, and conflict handling on reconnect.

Control CDN, transcoding, and storage costs as course video delivery scales. See the egress math, the levers that cut it, and when to build vs buy.