Re: #backgroundColor + <image>

Hi Glenn,

The specification is unclear at best: the #backgroundColor definition
defers to TTML1, which has no concept of <image>.

Unambiguous feature designators are important since profiles like IMSC use
them to impose conformance requirements.

The approach taken with #padding, which adds capabilities introduced in
TTML2 as a separate feature designator, seems clear and explicit.

Best,

-- Pierre


On Tue, Feb 5, 2019 at 8:16 PM Glenn Adams <glenn@skynav.com> wrote:

> I should clarify. I think it is a bad idea to insist on combination
> feature definitions as a general rule, even when the combination comes into
> play in a new version that was not present in a previous version. In
> particular, I think if an implementation claims support for #backgroundColor
> (already) and add a claim for support for #image, then it should
> implement support for #backgroundColor on image as a natural
> interpretation of the specification language.
>
> What I hear (behind your question) is a desire to not support background
> color on an image (and to have a feature to control this). This sounds like
> a new use case and should be justified by making a business case for not
> supporting background color on image when an implementation otherwise
> claims support for #backgroundColor and #image.
>
> Have you made such a business case for non-support?
>
>
> On Tue, Feb 5, 2019 at 8:46 PM Glenn Adams <glenn@skynav.com> wrote:
>
>> Feel free to file an issue. As for myself, I'm ok with the current state
>> of affairs.
>>
>> On Tue, Feb 5, 2019 at 8:32 PM Pierre-Anthony Lemieux <pal@sandflow.com>
>> wrote:
>>
>>> Hi Glenn,
>>>
>>> This would conflict with the objective of not expanding the conformance
>>> requirements of individual features defined in TTML1.
>>>
>>> For instance, #padding remains unchanged from TTML1,
>>> while #padding-version-2 includes both #padding and padding capabilities
>>> introduced in TTML2.
>>>
>>> Best,
>>>
>>> -- Pierre
>>>
>>> On Tue, Feb 5, 2019 at 5:22 PM Glenn Adams <glenn@skynav.com> wrote:
>>>
>>>> My reading says it is #backgroundColor, which, as written (now and in
>>>> TTML1), did not distinguish which elements it applied to, so, by virtue of
>>>> the upgraded *applies to* in TTML2 for tts:backgroundColor, it would
>>>> effectively apply (now) to image as well.
>>>>
>>>> On Tue, Feb 5, 2019 at 1:50 PM Pierre-Anthony Lemieux <pal@sandflow.com>
>>>> wrote:
>>>>
>>>>> Hi all,
>>>>>
>>>>> Which TTML2 feature covers tts:backgroundColor when applied to <image>?
>>>>>
>>>>> Perhaps it is included in #image?
>>>>>
>>>>> Best,
>>>>>
>>>>> -- Pierre
>>>>>
>>>>