- From: David Singer <singer@apple.com>
- Date: Mon, 27 Jan 2014 18:35:06 -0800
- To: Silvia Pfieffer <silviapfeiffer1@gmail.com>
- Cc: Nigel Megitt <nigel.megitt@bbc.co.uk>, "public-texttracks@w3.org" <public-texttracks@w3.org>
On Jan 26, 2014, at 18:23 , Silvia Pfeiffer <silviapfeiffer1@gmail.com> wrote: > On Fri, Jan 24, 2014 at 9:07 PM, Nigel Megitt <nigel.megitt@bbc.co.uk> wrote: >> The general problem with allowing the client to position cues that overlay >> other visual content, e.g. video,is that this does not take into account >> information that the viewer needs from that visual content itself. For >> example many hard of hearing users of captions need to see the mouths of >> people talking as well as the caption text. And some video content >> contains burnt-in text that is essential for understanding the programme. >> Traditionally this is managed by editorial effort to position the captions >> carefully at the authoring stage, at least in those formats that permit >> positioning data to be expressed. > > Right. So, the idea is that if the content was authored well, the > rendering in the browser will never have to deal with overlap > avoidance. > > However, not all content is authored well. For example content is > authored for a specific font size. If that font size is increased by > the user, or by a custom style sheet, the browser still should do its > best to render content in such a way that it's readable. If it can > move lines slightly and thus avoid overlap, surely that's preferable > to captions that overlay each other. It does seem that resolving these together is hard: * we prefer the cues to overlay the content because, even though they obscure part of the content, when they are there one doesn’t need to change one’s focus (move the eyes) * we prefer to allow the user the option to override fonts, font sizes, colors, and other styles I note, for example, it’s possible for the user to over-ride the text and/or background colors so that the text is invisible in some cases. (“I prefer blue text on a transparent background” — until I watch a movie about skydiving, where the background is blue sky). I really don’t like saying to the users “in *theory* what the source sends for styling are defaults that you can over-ride; but, they are mandatory defaults, and if you over-ride them, some captions may be more visible bit some a lot less so”, either. Nor do I like a system that is complicated by covering the cases of the few users who do, indeed, over-ride. And indeed, testing one’s content that ‘reasonable’ things happen when the users do over-rides is hard (well, there are multifarious possible over-rides). David Singer Multimedia and Software Standards, Apple Inc.
Received on Tuesday, 28 January 2014 02:35:47 UTC