- From: Glenn Maynard <glenn@zewt.org>
- Date: Mon, 24 Jan 2011 18:45:55 -0500
On Mon, Jan 24, 2011 at 4:17 PM, Philip J?genstedt <philipj at opera.com>wrote: > Maybe you could enable them all by default and let users disable the ones > they don't like? Few people would use it if the unwanted tracks had to be manually turned off every time, though. I know I wouldn't bother. As far as I'm aware no one has experimented with the rendering parts of > WebVTT yet. It's defined in < > http://www.whatwg.org/specs/web-apps/current-work/multipage/rendering.html#rules-for-updating-the-display-of-webvtt-text-tracks> > and is a little layout engine that tries to avoid overlapping. Implementing > that and seeing what happens is the best way to find out if it's sane or > not. > > Do you have a working example of such a multi-conversation scene and how it > should be rendered? That would be quite interesting to have a look at. Here's one that I think was done very well, rendered statically to make sure we're all seeing the same thing: http://zewt.org/~glenn/multiple%20conversation%20example.mpg The results are pretty straightforward. One always stays on top, one always stays on the bottom, and most of the time the spacing between the two is correct--the normal distance the UA uses between two vertical captions (which would be lost by specifying the line height explicitly). Combined with the separate coloring (which is already possible, of course), it's possible to read both conversations and intuitively track which is which, and it's also very easy to just pick one or the other to read. One example of how this can be tricky: at 0:17, a caption on the bottom wraps and takes two lines, which then pushes the line at 0:19 upward (that part's simple enough). If instead the top part had appeared first, the renderer would need to figure out in advance to push it upwards, to make space for the two-line caption underneith it. Otherwise, the captions would be forced to switch places. (I don't know how to do this in general while maintaining the goal of semantic markup over presentation markup, but I think it's worth thinking about carefully.) As an aside: the font stroke (the outline around each letter) in the above clip helps readability substantially. A solid font color always tends to blend into the background in places, where a two-color stroked font provides its own contrast. I've used the same thing in game UIs rendered on top of a moving background. Tangental, but I figured I'd point it out. -- Glenn Maynard
Received on Monday, 24 January 2011 15:45:55 UTC