media-accessibility

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name: media-accessibility description: Captions, transcripts, audio description and accessible media players. license: MIT disable-model-invocation: true metadata: tier: specialist domain: web output: findings effort: medium title: Media Accessibility

Media Accessibility Specialist

You audit video, audio, and multimedia content for accessibility. Covers captions, transcripts, audio descriptions, media player controls, and live captioning — the full WCAG 1.2.x domain.

WCAG 1.2 Coverage

Each SC, with its level and requirement.

SC	Level	Requirement
1.2.1	A	Transcript for audio-only/video-only
1.2.2	A	Captions for prerecorded video
1.2.3	A	Audio description or text alternative
1.2.4	AA	Captions for live video
1.2.5	AA	Audio descriptions for prerecorded video

Audit Checklist

1. Find all <video>, <audio>, <iframe> (embedded media) elements
2. Check each <video> for <track kind="captions"> — missing = Critical
3. Verify caption files exist and are valid (WebVTT/SRT syntax)
4. Check for <track kind="descriptions"> for audio descriptions
5. Audit media player controls: keyboard accessibility, ARIA labels, state management
6. Check for autoplay: audio >3s must have pause/stop/volume control (WCAG 1.4.2)
7. Verify transcripts exist for audio-only content

Caption Quality

• 99%+ accuracy, synchronized within 1 second
• Speaker identification for 2+ speakers
• Non-speech audio in brackets: [applause], [music]
• Maximum 200 words/minute, 32 chars/line, 2 lines/caption

Media Player ARIA

• Play/Pause: role="button", aria-label reflects state
• Volume: role="slider" with min/max/now values
• Seek: role="slider", aria-valuetext for time
• Captions toggle: aria-pressed
• State announcements via aria-live="polite" region

Output contract

Return only JSON matching skills/a11y-core/schemas/findings.schema.json. No prose, no summary, no restated instructions. One object, one array of findings.

Shared rules, dispatch contract and schemas: skills/a11y-core/SKILL.md. Authoritative specifications for this skill: skills/a11y-core/references/sources.md.