19273 2012-10-04 10:19:48 +0000 WebVTT: Define a default value for 'line-height' 2012-12-31 05:42:57 +0000 1 1 1 Unclassified TextTracks CG WebVTT unspecified PC All RESOLVED WORKSFORME P2 normal --- 1 silviapfeiffer1 ian ian mike philipj public-texttracks zcorpan dave.null oldest_to_newest 75301 0 silviapfeiffer1 2012-10-04 10:19:48 +0000 Section 3.5.1 defines default settings for CSS values. It includes a default font of '5vh', i.e. 5% of video height. When "line" cue settings are provide as line numbers, we need to provide exact positioning. However, line heights are different between browsers - CSS only specifies that line-height should be between 1.1 - 1.3 times the font height. To get exact line positioning, we should also provide a default setting for line-height. 77072 1 silviapfeiffer1 2012-10-24 21:51:03 +0000 I'm finding that this looks best: line-height: '5vh' font: '5/1.3vh sans-serif' This has the result that every browser covers the video viewport with 20 lines exactly, rather than being random. 78585 2 ian 2012-11-21 19:19:15 +0000 CSS specifies that the line height is 'normal' which is derived fron the font metrics. We could set the line-height to 6.5vh as you suggest, but then it would have overlap in cases where the font's metrics are able to suggest a better line height (e.g. Zapfino). zcorpan, foolip: any opinion on this? 78606 3 silviapfeiffer1 2012-11-21 20:45:22 +0000 This is a problem of compatibility between browsers, which each interpret "normal" differently, not just for different fonts, but for the same font. 78618 4 ian 2012-11-22 00:14:41 +0000 If they're interpreting the font metrics differently, file a bug on the browsers getting it wrong. 78642 5 zcorpan 2012-11-22 09:50:09 +0000 I think we should keep 'normal' in WebVTT as the default. It should be possible for authors and users to change font and have the line height follow appropriately. If you want a certain number of lines, you can set line-height. That browsers differ in line-height for the same font is a bug.