1 / 29

Timed Media Accessibility: Surveying the terrain

. Timed Media Accessibility: Surveying the terrain. David Singer, with help from the web media team Apple Inc. INTRODUCTION. The 3 legs of good accessibility. Specifications and tutorials Authors Users and user agents. Dream: do better than than TV. Good framework for accessibility

denis
Download Presentation

Timed Media Accessibility: Surveying the terrain

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Timed Media Accessibility: Surveying the terrain David Singer, with help from the web media team Apple Inc.

  2. INTRODUCTION Timed Media Accessibility

  3. The 3 legs of good accessibility • Specifications and tutorials • Authors • Users and user agents Timed Media Accessibility

  4. Dream: do better than than TV • Good framework for accessibility • immediate needs • innovation and increasingly effective future provisions • Use web technologies • Use preferences • Be bright! Timed Media Accessibility

  5. The problem space • Timed accessibility • captions, audio, sign language • Untimed accessibility • transcripts, alternatives Timed Media Accessibility

  6. TIMED ACCESSIBILITY Timed Media Accessibility

  7. Audio • Captions • (Subtitles) • Sign language • Contrast etc. issues Timed Media Accessibility

  8. Video • Audible description of video • Contrast etc. issues • Seizure avoidance (e.g. Epilepsy susceptibility) Timed Media Accessibility

  9. General and Time Management • ‘Slide-flipping’ in parallel with the media • Rate preferences (e.g. normally at 80%) Timed Media Accessibility

  10. UNTIMED ACCESSIBILITY Timed Media Accessibility

  11. Two un-timed challenges • Links to transcripts • Alternative, longdesc and fallback content Timed Media Accessibility

  12. INSIDE OR OUTSIDE THE MEDIA CONTAINER? Timed Media Accessibility

  13. Inside • Burned-in (open) captions • ‘Overlay’ Timed text tracks • Audio narration (description) • Sign-language (video) tracks Timed Media Accessibility

  14. Outside • Captions – scripted or second player Timed Media Accessibility

  15. MEETING NEEDS Timed Media Accessibility

  16. Handling timed accessibility • select the resource which has or can have the provision needed • configure it if it’s an optional feature Timed Media Accessibility

  17. User selection • By preference • By action • Either/Both? Timed Media Accessibility

  18. Hypothesis • ‘Somewhere’ there can be user preferences • Axes: • Captions (subtitles?) • Audio description of video • Sign language • Seizure avoidance, contrast, etc. Timed Media Accessibility

  19. Source selection • Use <source> media query • Allow it to enquire the user’s presentational needs Timed Media Accessibility

  20. Discussion • Simple rules: match prefs-source FAILS if either: • user has a need, and the source says it explicitly does not support it • user does not have a need, and the file is tagged to support it • Second rule is needed so users not wanting (mentioning) a need will skip sources tagged as explicitly for it (e.g. open captions) Timed Media Accessibility

  21. In Tabular Form Timed Media Accessibility

  22. Examples • <source media=“accessibility(captions:yes)” src=“A”/> • <source src=“Z”/> • <source media=“accessibility(captions:yes audio-description:no)” src=“A”/> • <source media=“accessibility(captions:no audio-description:yes)” src=“A”/> • <source src=“Z”/> Timed Media Accessibility

  23. Source Configuration • If source has ‘optional’ features (e.g. a separate text overlay stream for captions) • Let the media engine default enable/disable track the user preferences [out of scope] • Let scripts: • enquire user preference • enquire source provision (‘is there a caption track?’) • affect source configuration (‘turn on caption track’) Timed Media Accessibility

  24. PRESENTATION ISSUES Timed Media Accessibility

  25. Who renders captions? • In media file: media engine • Handled by script and placed into DOM: web engine Timed Media Accessibility

  26. Scripted Accessibility • Enables custom controllers to turn provisions on/off • Sync’ing slides, scripted captions etc. • Cue ranges, where art thou? Timed Media Accessibility

  27. LEVERAGE AND ACTION Timed Media Accessibility

  28. Resources • SMIL for synchronized media • Media queries for presentation needs • Media engine accessibility provisions • Scripting, the DOM and events • Dublin Core and IMS for user preferences? Timed Media Accessibility

  29. Action? • HTML: • revive cue ranges • describe using media queries to select for accessibility (informative) • describe using user preferences to configure for accessibility (informative) • Script access to or control of features of the media • CSS • Media queries for accessibility Timed Media Accessibility

More Related