Re: IMSC1 WD wide review and CR draft.

Now added to the Comment tracker tool.
https://www.w3.org/2006/02/lc-comments-tracker/34314/WD-ttml-imsc1-20140930/

On 27/10/2014 12:07, Andreas Tai wrote:
> Hi Thierry,
>
> First congratulation to the very good spec document!
>
> Apart from a few issues most of my observations are not critical. They
> can be seen more as a proposal for the editor. I am sending the comments
> on my behalf.
>
> The more important issues first:
>
> ----------------------------------
> 5.2 Foreign Elements and Attributes
> -----------------------------------
> It would be good to give more emphasis that a presentation processor
> should not reject a document "with foreign namespace elements or
> attributes".
>
> Examples for possible edits:
> a) "...*The subtitle document SHALL be processed but* such elements and
> attributes may be ignored by the presentation processor or
> transformation processor."
>
> b) "A *conforming* subtitle document may contain elements and attributes
> that are neither specifically permitted nor forbidden by a profile."
>
> It may be a good idea to align this paragraph with the section in TTML
> 5.3.2. As far as I can see it is not explicitly forbidden to use the
> IMSC namespaces for extensions. So either in IMSC 1 5.3 or somewhere
> else an additional constraint may be added.
>
> -----------------------------------
> 5.10 Features (Common features) #length-cell feature
> -----------------------------------
> IMSC 1 states that the #length-cell feature shall not be used. The
> line-padding extension uses the cell metric. Not sure if this causes a
> problem. On the one hand the extensions are "outside" of TTML 1 on the
> other hand they use the cell metric as defined by TTML 1.
>
> -----------------------------------
> 5.10 Features (Common features) -#length feature
> -----------------------------------
> The #length feature includes the support of the "c" metric
> (http://www.w3.org/TR/ttml1/#feature-length). So you may add a
> restriction here.
>
> Some other observations in document order:
> ------------------------------
> 3. Conformance
> ------------------------------
> The term "subtitle document" is not defined in IMSC 1 and TTML 1 but
> used frequently in a normative context. It may be helpful to define it
> in Section 2.
>
> ------------------------------
> 4.1 General
> ------------------------------
>  From IMSC 1:
> "In addition, the Text Profile subtitle document SHOULD be associated
> with the Image Profile subtitle document such that, when image content
> is encountered, assistive technologies have access to its corresponding
> text form."
>
> As far as I could see there is no defined method to link a Text profile
> document to an Image Profile document through an element in the document
> themselves. So it may helpful to add that his has to be done through an
> external setting.
>
> ------------------------------
> 5.7.3 itts:forcedDisplay - value matrix
> ------------------------------
> In general I would welcome a bit more text about the details of value
> combinations. There is text for "displayForcedMode=true,
> itts:forcedDisplay=false" but not for "displayForcedMode=true,
> itts:forcedDisplay=true". Maybe a matrix would be helpful with
> tts:visibilily (visible, hidden), displayForcedDisplay parameter (true,
> fase) annd itts:forcedDisplay (true, false).
>
> ------------------------------
> 5.7.3 itts:forcedDisplay - Informative Note
> ------------------------------
> The first note could possibly be improved if it is noted that this has
> an effect only if a "non-transparent background" is directly defined for
> the region (e.g. in most cases I have seen for the usage of EBU-TT-D the
> background will be applied through the content elements).
>
>
> ------------------------------
> 5.7.4 ittm:altText - Optionality of attributes
> ------------------------------
> For the XML Representation you may repeat the part from 2.3 TTML 1 where
> it states that bold-face attribute names are required and the others are
> optional (personally I would prefer the keyword "REQUIRED" after the
> attribute name). Without that it may not be clear if the attributes are
> optional or required.
>
>
> ------------------------------
> 5.7.4 ittm:altText - Typo
> ------------------------------
> End of "Note:": Replace ". ." with "."
>
> ------------------------------
> 5.10 Features (Common)
> ------------------------------
> #timing: It may be helpful to describe what you mean with the same
> syntax (e.g. is 00:00:01, 00:00:01.0 and 00:00:01.000 a different syntax?)
>
> ------------------------------
> 6.3 Features (Text Profile)
> ------------------------------
> #textAlgin: A reference to the definition of the "defaultRegion" in TTML
> 1 would be helpful. I assume that ony the TTML experts know what the
> defaultRegion is (e.g. some implementers gave in a TTML document
> "defaultRegion" as value for xml:id).
>
> -----------------------------
> 8.2 Reference Fonts
> -----------------------------
> A reference to presentation processors and transformation processors may
> be helpful. A presentation processor SHALL lay out the text according to
> the metrics and a transformation processor should use this metrics for
> any calculation.
>
> ------------------------
> Annex B Forced Content
> ------------------------
> A code example may be an illustrative help for the shown use case.
>
> Best regards,
>
> Andreas
>

Received on Tuesday, 4 November 2014 16:53:42 UTC