- From: John Foliot <jfoliot@stanford.edu>
- Date: Wed, 30 Jun 2010 14:27:34 -0700 (PDT)
- To: "'HTML Accessibility Task Force'" <public-html-a11y@w3.org>
- Message-ID: <008501cb189b$0e290d40$2a7b27c0$@edu>
Sign Translation (6 comments) http://www.w3.org/WAI/PF/HTML/wiki/Media_Accessibility_Requirements#Sign_T ranslation http://www.w3.org/2002/09/wbs/44061/20080526_media-requirements/results#xq 9 Q: Decoding and rendering multiple streams is even more difficult with video than with audio. Video decoding hardware used in many mobile devices is not able to decode more than one video stream simultaneously. A: Make this requirement a SHOULD requirement for browsers. Strong authoring guidance for content creator will mitigate situations where user-agents are unable to support multiple video streams (WCAG) - for example, on mobile devices that cannot support multiple streams, authors should be encouraged to offer 2 versions of the media stream, including one with signed captions burned into the media Comment: describe better the two cases: of picture in picture (where the background portion of the sign video is visible to the user), and alpha blended; where only the signer and no background is mixed onto the main video. Note that SL could also be in a separate window frame to the main video (main video for example being resized, this is sometimes done in TV broadcast) (SL-1) Support sign language video either as a track as part of a media resource or as an external file. Q: I think you need to support multiple tracks for different sign languages if they are available and allow the user to specify which one is presented. A: this would be addressed using <trackgroup>, as it is done for multiple languages for captions (SL-2) Support the synchronized playback of the sign language video with the media resource. (SL-3) Support the display of sign language video either as picture-in-picture or alpha-blended overlay, as parallel video, or as the main video with the original video as picture-in-picture or alpha-blended overlay. Q: (SL-3) What is "as parallel video"? "as picture-in-picture or alpha-blended overlay" and "as the main video with the original video as picture-in-picture or alpha-blended overlay" also seem to mean exactly the same thing, am I missing something? A: Either: 2 videos are played in synch, and placement (including alpha-blends) is handled by CSS. Parrallel video means 2 discrete videos playing in synch with each other ( Q: Note that <track> may not be the solution for this, rather linking several <video> elements together seems like a more reasonable solution if the video tracks are from separate resources. A: It is preferable to have one discrete <video> element contain all pieces for synch purposes (SL-4) Support multiple sign language tracks in several sign languages. (SL-5) Support the interactive activation/deactivation of a sign language track by the user. John Foliot / Eric Carlson
Received on Wednesday, 30 June 2010 21:28:09 UTC