- From: Ian Jacobs <ij@w3.org>
- Date: Thu, 07 Jun 2001 16:53:40 -0400
- To: w3c-wai-ua@w3.org
- CC: stephp@real.com, cindy.king@gallaudet.edu, geoff_freed@wgbh.org, ehodge@real.com
7 June 2001 UA Guidelines Teleconference Agenda announcement: http://lists.w3.org/Archives/Public/w3c-wai-ua/2001AprJun/0245 Minutes of previous meeting 31 May: http://lists.w3.org/Archives/Public/w3c-wai-ua/2001AprJun/0230 Next meeting: 14 June Present: Jon Gunderson (Chair), Ian Jacobs (scribe), Stephanie Potter (RealNetworks), Erik Hodge (RealNetworks), Geoff Freed (WGBH), Harvey Bingham, Mary Beth Janes (Apple), Mickey Quenzer, David Poehlman, Cindy King (Gallaudet) Regrets: Tim Lacy, Jim Allan, Eric Hansen, Gregory Rosmaita Reference document 4 June 2001 Guidelines: http://www.w3.org/WAI/UA/WD-UAAG10-20010604/ ---------------------- Discussion ---------------------- Issue 500: Checkpoint 4.6 positioning requirement. http://server.rehab.uiuc.edu/ua-issues/issues-linear-lc3.html#500 Accessibility requirements: * Move captions off of video (interference) * Move captions over video track (low vision) CK: One reason to allow for overlapping is that the author has not provided the captions; a third-party has provided the captions. One example is television. IJ: People have asked us why top/bottom/left/right is not sufficient. CK: If you have a video with wording already on it (e.g., there are alerts at the bottom of the screen), you can't always assume that the caption will go in a particular location (where there might be critical location). GF: I think that Quicktime does this already. /* Ian introduces the issue */ EH: I'd like to speak to the points about system-captions: * We're not making any plans to change our SMIL 1 behavior. * We're working on our SMIL 2 implementation. (There are some additional switches for subtitles.) The author places captions in a particular location. IJ: Is your concern override of author style or the reflow issue? EH: The latter. Sometimes there are interdependencies. There is also the ability within SMIL to move regions. The author can allow control of regions (e.g., on keyboard events). IJ: That's why we suggested that it would be possible to render the captions in a separate viewport. EH: Yes, that could be done. IJ: The transparency part would be covered by control of foreground and background colors (checkpoint 4.3, which is separate). EH: In the Windows environment, this can be done: allowing one viewport to show through another. MBJ: I'm mostly here to take questions back to our group. EH: If the author doesn't specify that the captions are in a separate viewport, does the UAAG requirement still apply? SP: Suppose the author creates a presentation with both video and captions in the same viewport. IJ: Our requirement still holds, and there are several implementation options: same viewport, different viewport. SP: It can get complicated if you pull, say, four different captions out into four different viewports (e.g., in different languages or multiple speakers, or a news presentation with one media window, one window with a stock ticker). IJ: But if the author can already specify that, why is it more complicated? SP: If it's allow only what the author can do, then that's less of a problem. IJ: Right, we don't require any more than what the author can do. CK: Check out http://depts.gallaudet.edu/ /* IJ checks out this page, but it's almost empty... */ CK: Most of the time you want captions in a separate viewport. Authors don't want their visual space left blank in cases where the users don't want to view captions. EH: Question: If you have captions below the video and the user requests that the captions go in a separate viewport, would it go against the spec if we left the text in place and created a separate window? IJ: I think it would be ok if the first captions were not overlapping with the video, and the user wanted to move the (second) captions to overlap the video. HB: The one they move around would be enlarged text. IJ: Why not allow two configurations: 1) view in place 2) view in separate viewport IJ: Allow the user to toggle them independently. In short: the tool already does what we want, but not always when we want it. We are asking for configuration to do these things even when the author hasn't said so. MQ: A good reason to have captions in a separate viewport is to allow users with screen access programs to zero in on specific information. DP: Some users may find it confusing to have too many captions tracks running simultaneously. Users may want to turn them on and off independently. GF: I was a little puzzled by the scenario where you have two captions regions at once. IJ: How important is transparency? CK: Traditionally captions have a background. Having a black background behind white lettering is preferred. We did some research a few years back with deaf users. We did shadowing and other variations, and, because of the video behind it, the users preferred a background. I think transparency is an important option, but shouldn't be a requirement. EH: I think that whether you have a requirement for transparency or not, our QA department would require it of us. IJ: Our spec says: "Note: When captions overlap the synchronized visual track, the user should be able to view the visual track behind the captions." IJ: I think we would need to be clearer that transparency should be a configurable option. /* Ian reads 4.6 of 4 June 2001 draft */ EH: Clarifying a: If the author can specify it, the user can? IJ: Yes. IJ: Is it reasonable to think of an implementation where the user can change values in the DOM? EH: The SMIL DOM will probably not be in the SMIL 2 Recommendation. We're interested in the SMIL DOM, however. We would implement all DOM things in one effort. People want to read the DOM data more than write values into the DOM. /* Review of RN comments from 10 May */ RealNetworks: "3.2 Difficult to apply to a SMIL playback environment in a useful way. Unlike HTML, *all* media (text included) is done as included media which the SMIL engine itself has little knowledge of. IJ: Wouldn't the player simply not hand off the content to another plug-in? EH: The SMIL player would have to query the server for information about the content type. At that point, it could choose not to play the information. It's not as simple as it sounds. EH: Would silent playing satisfy 3.2? IJ: Yes. We've talked about that explicitly. RealNetworks: "3.3 Seems mutually exclusive with 2.5. May require changes to client-server protocol for RealText, seems very difficult for Live Text applications, and may not be possible in other settings." IJ: We distinguish streaming content from animated presentation of that content. E.g., movie subtitles are streamed but not animated. EH: We use text as building blocks. But animation is about moving glyphs. The problem with letting it be "still". E.g., a series of news items that scroll up and constantly refresh. IJ: We've already said you can drop packets. EH: I'm ok with that. EH: With a marquee, there's no concept of a line break. EH: Would a source view be sufficient? IJ: In my opinion, not ideal, but sufficient. JG: Yes, I think that a source view would be sufficient. Casual users may not realize that a source view would satisfy their needs. It seems like there's an authoring issue here, as well. JG: How much flexibility does the author have in breaking up the text into chunks? SP: Typically it will all be done in one request. Suppose you are pulling content from a database. EH: I think that streaming text format presentation should be done on the client side. IJ: Do you throw away received text content? EH: There are configurations (loop=true) where we keep content. But in general, we throw out content as soon as it's not visible any more. MQ: But I may not have had time to read the text that's arriving. IJ: In general, we say don't rely on the author's time specification. DP: I'm not sure that real text can be used by a screen reader anyway. In order for real text to work with screen readers, it would have to be converted to something usable. EH: You could create a realtext window that is 10k pixels high (for, say, 1000 lines), and allow the user to scroll through it. /* GF and EH are working on a new standard for streaming text */ GR: I've been coordinating this with the WAI PF WG. In fact, I think it's on the agenda for the next WAI PF call. Resolved: - Checkpoint 3.3 does not allow the user agent to drop packets in the case of streaming content. The user must have access to all the same content, but in non-animated and non-blinking form. ---------------------- Future plans ---------------------- JG: We expect to invite developers during Candidate Recommendation to talk about Action IJ: Send IJ comments (to RN review) to stephp@real.com -- Ian Jacobs (ij@w3.org) http://www.w3.org/People/Jacobs Tel: +1 831 457-2842 Cell: +1 917 450-8783
Received on Thursday, 7 June 2001 16:54:23 UTC