[ttml2] [compute containment|over scaling] likely to fail (#1108)

nigelmegitt has just created a new issue for https://github.com/w3c/ttml2:

== [compute containment|over scaling] likely to fail ==
The requirement for success in the first step of `[compute containment scaling]` and `[compute over scaling]` is that the units of TR and RR are the same, but this is rarely likely to be the case.

Propose replacing with a step to re-express image dimensions in the document coordinate space so that the resulting units are always the same.

> In terms of units, there's no way any image resource will sensibly have, say, `rw` or `%` units, unless some processing step upstream has deliberately taken the intrinsic dimensions and re-expressed them in those units to get to TR. If the intent is to constrain document instances to express positions and sizes in pixels if they use embedded images, it's a strange way to achieve that goal.

_Originally posted by @nigelmegitt in https://github.com/w3c/ttml2/pull/1098_

Please view or discuss this issue at https://github.com/w3c/ttml2/issues/1108 using your GitHub account

Received on Monday, 3 June 2019 08:30:53 UTC