Re: Style inheritance in TTML1

Hi Glenn,

Thanks for the quick reply.

> "if PINH is present in the specified style set of E, SSS(E), then continue to the next inheritable style property;"

Ok.

Can we add the example above to Section 8.4.4.2 at next revision on TTML1?

Best,

-- Pierre

On Thu, Jul 16, 2015 at 9:23 AM, Glenn Adams <glenn@skynav.com> wrote:
>
>
> On Thu, Jul 16, 2015 at 9:09 AM, Pierre-Anthony Lemieux <pal@sandflow.com>
> wrote:
>>
>> Hi all,
>>
>> The following question came up while evaluating a rendering of the
>> IMSC1 test at [1], which has the following structure:
>>
>> ...
>> <style xml:id="black_72" tts:color="black"
>> tts:fontFamily="proportionalSerif" tts:fontSize="72px"
>> tts:textAlign="center"/>
>> <style xml:id="white_73" tts:color="white"
>> tts:fontFamily="proportionalSansSerif" tts:fontSize="73px"
>> tts:textAlign="right"/>
>> ...
>> <region xml:id="subtitleArea1" style="black_72" tts:origin="100px
>> 200px" tts:extent="1024px 690px" tts:padding="5px 5px"
>> tts:opacity="0.85" tts:textAlign="center"
>> tts:showBackground="whenActive" tts:wrapOption="noWrap"/>
>> ...
>> <div region="subtitleArea1">
>>     <p begin="00:00:00:10" end="00:00:00:13"
>> tts:backgroundColor="#97BF0D" style="white_73" tts:wrapOption="wrap"
>> tts:fontSize="24px">Start</p>
>> ...
>> <div>
>>
>> In which order do white_73 and black_72 get applied to the <p>?
>
>
> black_72 is never directly applied to p (or div or body); it is applied to
> the region in which the body/div/p subtree is targeted; so, when resolving
> style properties on p, only those inheritable properties not already
> assigned to p would be inherited from div, body, and region, in that order;
> so only inheritable properties not assigned to p, div, and body would be
> inherited from region through the region/body/div ancestors;
>
>> Per Section 8.4.4.2 in TTML1, I think I would conclude that inherited
>>
>> styles get applied last (and thus <p> is centered) since [implicit
>> inheritance] is the last rule.
>
>
> the resolved textAlign will be right, not center; step 6. (a) of 8.4.4.2:
>
> "if PINH is present in the specified style set of E, SSS(E), then continue
> to the next inheritable style property;"
>
> means that tts:textAlign will not be inherited since tts:textAlign was
> already merged from white_73 into SSS(E) in step 2;
>
> you should also review the updated language in TTML2 10.4.4.2 step 6, which
> adds missing language that deals with initial value fallback (that was
> accidentally omitted in TTML1 [1]);
>
> [1] https://www.w3.org/AudioVideo/TT/tracker/issues/399
>
>
>>
>>
>> Does that sound right?
>>
>> Thanks,
>>
>> -- Pierre
>>
>> [1]
>> https://dvcs.w3.org/hg/ttml/file/tip/ttml-ww-profiles/testsuite/dece/Solekai023_1920_23_1x1_MaxHdSubtitle_v7_subtitles/track6-frag0-sample1-subs0.ttml
>>
>

Received on Thursday, 16 July 2015 17:56:56 UTC