search

w3c / imsc-tests

IMSC test suites
https://w3c.github.io/imsc-tests/
Other
16 stars 13 forks source link

Clarify expected results of Span004 #110

Closed simontsang closed 9 months ago

simontsang commented 9 months ago

Could you confirm that the rendering of Span004 is as expected?

Section 7.2.3 of the TTML 1.0 specification states that for xml:space="default", white-space should be treated as

suppress-at-line-break="auto" linefeed-treatment="treat-as-space" white-space-collapse="true" white-space-treatment="ignore-if-surrounding-linefeed"

There's a discussion over at the Shaka Player repo (https://github.com/shaka-project/shaka-player/issues/4974) about how this should be rendered – specifically whether the white-space surrounding the span tags should be collapsed or not. The interpretation from the Shaka Player team is that this space should be collapsed, and so should render this text as mustredandgreen. This is at odds with the example provided in the render which reads as must red and green

I would very much appreciate if you could confirm whether this is...

  1. a mistake in the test
  2. a mistake in the reference implementation, or...
  3. a misunderstanding of the spec by the Shaka team

Thanks!

palemieux commented 9 months ago

As far as I know, white-space-collapse="true" means collapsing sequences of white spaces into one white space and not removing all white spaces.

nigelmegitt commented 9 months ago

Agree with @palemieux - it's "3. a misunderstanding of the spec by the Shaka team": with xml:space="default" runs of one or more "white space" characters are collapsed down to 1 space (0x20) character not zero.

simontsang commented 9 months ago

That's great - thanks for the clarification.

joeyparrish commented 9 months ago

Thanks!