Open skynavga opened 4 years ago
This makes IMSC1.1 incompatible with both IMSC1.0
IMSC 1.0 specifies that the tts:extent attribute SHALL be present on all region elements, where it SHALL use px units or "percentage" syntax, thereby effectively prohibiting #extent-auto
.
The language is ambiguous since px units and percentage syntax only apply to length expressions. To remove the ambiguity, the language should be changed to read
The tts:extent attribute SHALL be present on all region elements, where it SHALL use
<length>
expressions that specify px units or "percentage" syntax.
@skynavga Did you consider the prose in the latest Editor's Draft?
ok, the language is fine in 1.2
Can we close this issue then @skynavga?
Summary:
8.4.2 #extent-region The tts:extent attribute SHALL be present on all region elements, where it SHALL use px units, percentage values, or root container relative units.
is replaced with:
8.4.2 #extent-region For each region element defined in the Document Instance, the specified value of the tts:extent style property SHALL consist of two length expressions that use pixel (px), percentage (%), or root container relative units.
The Timed Text Working Group just discussed #extent-root implies support for #extent-auto imsc#489
, and agreed to the following:
SUMMARY: Reconsider the wording for this in conjunction with IMSC 1.2 #475 and come up with something all are happy with.
RESOLUTION: Approve this erratum as summarised at https://github.com/w3c/imsc/issues/489#issuecomment-562895235
IMSC1.0 specifies that #extent-root is permitted, and #extent-root implies support for #extent-auto (see note in TTML2 §E.1.92); however, IMSC1.1 does not include #extent-auto in §6, which would mean that #extent-auto is prohibited in IMSC1.1. This makes IMSC1.1 incompatible with both IMSC1.0 and TTML2 regarding the semantics of #extent-root.