14106 2011-09-11 15:42:40 +0000 <track> Chapter tree construction algorithm requires source order; is broken using sorted cue order 2011-09-22 09:17:53 +0000 1 1 1 Unclassified HTML WG HTML5 spec unspecified Other other RESOLVED FIXED http://www.whatwg.org/specs/web-apps/current-work/#text-tracks-describing-chapters P3 blocker --- 1 contributor ian annacc eoconnor eric.carlson giles ian mike philipj public-html-admin public-html-wg-issue-tracking silviapfeiffer1 public-html-bugzilla oldest_to_newest 56639 0 contributor 2011-09-11 15:42:40 +0000 Specification: http://www.whatwg.org/specs/web-apps/current-work/multipage/the-video-element.html Multipage: http://www.whatwg.org/C#text-tracks-describing-chapters Complete: http://www.whatwg.org/c#text-tracks-describing-chapters Comment: Construct chapter from from sorted cue order (drop source order depencies) Posted from: 65.51.202.21 User agent: Opera/9.80 (Windows NT 6.1; U; en) Presto/2.9.168 Version/11.51 56642 1 philipj 2011-09-11 15:53:39 +0000 Comments from the Open Video Conference, with implementors of Opera, Firefox, Chrome and Safari discussing WebVTT. http://people.opera.com/philipj/2011/09/ovc/demos/chapters.html was written to demostrate the chapter tree construction. Since the algorithm uses source order, it cannot be emulated using scripts operating on the cues. Problems: 1. We don't want to keep track of two order of the cues, because there's no reason to module this bug. 2. If you use the "text track cue order" the nesting will be wrong for chapters with the same start time, some chapters will be dropped. To see this, comment out the following from the example: /* list.sort(function(a, b) { if (a.startTime != b.startTime) return a.startTime - b.startTime; return b.endTime - a.endTime; }); */ Suggestion solution: Use the "text track cue order" but modify that concept to sort first by increasing start time, then by decreasing end time, then by insertion order. This solved problem, and actually improves the rendering order of captions that share start time but not end time (the top and shorter cue goes away first). 56646 2 philipj 2011-09-11 16:08:32 +0000 s/demostrate/demonstrate/ s/module/modulo/ (Dear W3C, please let me edit comments after posting.) 57016 3 ian 2011-09-20 00:13:36 +0000 Done. 57017 4 contributor 2011-09-20 00:14:08 +0000 Checked in as WHATWG revision r6557. Check-in comment: Change the text track cue order so that it reverse-sorts on end time, since that results in better rendering and fixes some chapter issues. Also, better define the order of events for multiple cues that started at the same time with different end times. http://html5.org/tools/web-apps-tracker?from=6556&to=6557