- From: Frank Olivier <franko@microsoft.com>
- Date: Fri, 27 Nov 2009 22:37:42 +0000
- To: Eric Carlson <eric.carlson@apple.com>
- CC: Philip Jägenstedt <philipj@opera.com>, Silvia Pfeiffer <silviapfeiffer1@gmail.com>, HTML Accessibility Task Force <public-html-a11y@w3.org>
After discussing it on our side - we agree that not having multiple element synchronization in this version of the spec is a good idea. As for captions: if captions are stylable via page css, what happens if the caption format itself specifies styling? Also, imo the user should be able to override page-specified styling, as they might prefer their own styling. On Nov 25, 2009, at 8:04, "Eric Carlson" <eric.carlson@apple.com> wrote: > > On Nov 25, 2009, at 4:24 AM, Philip Jägenstedt wrote: > >> I agree that syncing separate video and audio files is a big >> challenge. I'd prefer leaving this kind of complexity either to >> scripting or an external manifest like SMIL. >> > > +1 to keeping multiple element synchronization out of our spec! > > >> Below I focus on the HTML-specific parts: >> >> Captions/subtitles... The main problem of reusing <source> is that >> it doesn't work with the resource selection algorithm.[1] However, >> that algorithm only considers direct children of the media element, >> so adding a wrapping element would solve this problem and allow us >> to spec different rules for selecting timed-text sources. Example: >> >> <video> >> <source src="video.ogg" type="video/ogg"> >> <source src="video.mp4" type="video/mp4"> >> <overlay> >> <source src="en.srt" lang="en-US"> >> <source src="hans.srt" lang="zh-CN"> >> </overlay> >> </video> >> >> We could possibly allow <overlay src="english.srt"></overlay> as a >> shorthand when there is only one captions file, just like the video >> <video src=""></video> shorthand. >> >> I'm suggesting <overlay> instead of e.g. <itext> because I have >> some special behavior in mind: when no (usable) source is found in >> <overlay>, the content of the element should be displayed overlayed >> on top of the video element as if it were inside a CSS box of the >> same size as the video. This gives authors a simple way to display >> overlay content such as custom controls and complex "subtitles" >> like animated karaoke to work the same both in normal rendering and >> in fullscreen mode. (I don't know what kind of CSS spec magic would >> be needed to allow such rendering, but I don't believe overlaying >> the content is very difficult implementation-wise.) >> > I like the idea of an <overlay> element, but I don't understand > what you are proposing for when no usable source is found. Can you > elaborate please? > > >> If there is a use case, displaying several captions/subtitles at >> once could be allowed as such: >> >> <video src="video.ogg"> >> <overlay src="en.srt" class="centerTop"></overlay> >> <overlay src="hans.srt" class="centerBottom"></overlay> >> </video> >> > I also like this idea. I don't think it will be difficult to find > legitimate use cases, eg. displaying closed captions and subtitles > simultaneously. > > eric >
Received on Friday, 27 November 2009 22:38:18 UTC