Re: [SMIL30 LC comment] 13. SMIL 3.0 External Timing

 Dear Dr. Olaf Hoffmann ,

The SYMM Working Group has reviewed the comments you sent [1] on the Last
Call Working Draft [2] of the Synchronized Multimedia Integration Language
(SMIL 3.0) published on 13 Jul 2007. Thank you for having taken the time to
review the document and to send us comments!

The Working Group's response to your comment is included below.

Please review it carefully and let us know by email at www-smil@w3.org if
you agree with it or not before 02 nov 2007. In case of disagreement, you
are requested to provide a specific solution for or a path to a consensus
with the Working Group. If such a consensus cannot be achieved, you will
be given the opportunity to raise a formal objection which will then be
reviewed by the Director during the transition of this document to the
next stage in the W3C Recommendation Track.

Thanks,

For the SYMM Working Group,
Thierry Michel
W3C Staff Contact

 1. http://www.w3.org/mid/200708051349.52107.Dr.O.Hoffmann@gmx.de
 2. http://www.w3.org/TR/2007/WD-SMIL3-20070713/


=====

Your comment on 13.2 Introduction:
> Hello SMIL working group,
> 
> some comments on chapter 13
> 
> 
> 13.2
> 
> 'An alternative to Timesheets is XHTML+SMIL...'
> 
> -> reference XHTML+SMIL...
> -> this one? http://www.w3.org/TR/XHTMLplusSMIL/
>      (but this is for SMIL2.0)
> 
> ----------------
> 13.3
> 
> -> Add required title element to the XHTML example...
> -> Do not need all SMIL elements the prefix 'smil:' 
>      not just the first one?
>      Either one has to put the xmlns attribute into the
>      timesheet element, but then it is not needed in
>      the html element anymore...
> -> Why is the timing inside the XHTML document while
>      the module is called 'External Timing'? Seems to
>      be no ideal example for 'External Timing'?
> 
> ---
> 
> typo?
> 
> '<!DOCTYPE htmlLIC "-//W3C//DTD XHTML 1.0 
> Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml
> PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
> "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">'?    
> 
> ->
> '<?xml version="1.0"?>
> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
>     "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">'?
> 
> 
> ----------------
> 
>  13.7.2
> 
>  'The following example illustrates how the animate element can be 
>   used to animate CSS attributes of elements of the host language.
> <smil:timesheet>
>   <seq>
>     <item select=".Slide" dur="15s">
>       <par>
>         <item select=".Bullet" beginInc="3s">
>           <animate select=".Bullet" attributeName="marginLeft"
> values="200;0" 
> dur="1s" />
>         </item>
>       </par>
>     </item>
>   </seq>
> </smil:timesheet>'
>  
>  -> CSS properties or really attributes? If attributes reference an
> example
>       language...
>  -> 'attributeName="marginLeft"'  which language has a CSS 
>       property 'marginLeft'?
>       If this is defined in SMIL, this is maybe a good indication to
> reference
>       the definition here again ;o)
>  
>  -----------------
>  
>  13.8
>  
>  Index Function
>  
>  -> Add required title element to the XHTML example...
>  
>  -> wrong/senseless structure or example:
>  
>  '<head>
> <!DOCTYPE htmlLIC "-//W3C//DTD XHTML 1.0 
> Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml
> PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
> "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
> <html xmlns="http://www.w3.org/1999/xhtml"
>       xmlns:smil="http://www.w3.org/2007/07/SMIL30/Timesheets">
>   <head>
>     <smi:timesheet>
>       <par>
>         <excl>
>       ...'
> 
> ->
> '<?xml version="1.0" encoding="utf-8"?>
> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
>     "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
>     <html xmlns="http://www.w3.org/1999/xhtml"
>       xmlns:smil="http://www.w3.org/2007/07/SMIL30/Timesheets">
>   <head>
>     <smil:timesheet>
>       <smil:par>
>         <smil:excl>
>       ...'?
> 
> 
>   -> missing required alt attribute in img elements, if they are from
> XHTML as
>        indicated in the example    
> 
>   -> a practical problem with this example is, that the large images
> are all
>        loaded with the document at once, therefore the thumbnails are
> useless,
>        if all images are loaded anyway, this is ineffective for the
> purpose of
>        an image gallery and from the point of produced traffic, because
> the
>        user expects to have a choice to choose and load an image or
> not...
> 
> 
> -----------
> 
> General:
> 
> - why not to use an XML processing instruction to reference the
>   timesheet as a stylesheet?
>   <?xml-stylesheet href="timesheet.smil" type="application/smil+xml" 
>        title="a timesheet"  alternate="yes" ?>
>   then it is not needed to use another namespace in the XHTML-document
> 
>   and it is possible to use it alternatively or additionally to CSS...
> 
>   As a possible application:
> 
>   a) example.xhtml contains references to CSS-files and to
> timesheet-files
>       either with xml-stylesheet processing instructions or the link
> element.
>   b) all styling is in external files, some for CSS, some for
> timesheets,
>       depending on the processing instruction or the rel attribute of
> the link
>       element, the different stylings can be combined or used
> alternatively.
>   c) the user/reader can select the desired styling within the
> user-agent
>       depending on the defaults of the author or additional
> selectivity
>       possibilities of the user-agent
> 
> - because the author has not to mix different XMLs in one document and
> 
>   does not have to put SMIL code directly into the main document,
>   the document still validates with an 'ordinary' validator or in the
> case of
>   XHTML can still be served as text/html for backwards accessibility,
> if an
>   outdated viewer is not able to interprete application/xhtml+xml.
> 
> - example for a complete external document with a timesheet missing
> 
> - is it already planned/done to add ':timed-inactive' to a CSS3
> module?
>   If not, how to use it in a 'valid' CSS-file?


Working Group Resolution (LC-1796):
Here is the proposed resolution

1.---------------------------------------------------------
Q: 13.2
'An alternative to Timesheets is XHTML+SMIL...'
-> reference XHTML+SMIL...
-> this one? http://www.w3.org/TR/XHTMLplusSMIL/
(but this is for SMIL2.0)

A: Yes, the specification will include the missing reference
([http://www.w3.org/TR/XHTMLplusSMIL/])

2.------------------------------------------------
Q: 13.3
-> Add required title element to the XHTML example...

A: Yes, in HTML every document should include a title; so the example has
been updated in the SMIL specification as:

<head>
  <title>Timesheets example</title>
  ...
</head>

-------------------------------------------------

3.----------------------------------------------
Q: -> Do not need all SMIL elements the prefix 'smil:' not just the first
one?
Either one has to put the xmlns attribute into the timesheet element, but
then it is not needed in the html element anymore...

A: Yes. In this example there are some problems with the namespaces

The specification has been updated as:

<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:smil="http://www.w3.org/ns/SMIL30">

 <head>
    <smil:timesheet>
      <siml:seq>
        <smil:item select="#Slide1" dur="5s" />
        <smil:item select="#Slide2" dur="5s" />
        <smil:item select="#Slide3" dur="5s" />
      </smil:seq>
    </smil:timesheet>
  </head>
-------------------------------------------------------------

4.----------------------------------------------------------
Q: -> Why is the timing inside the XHTML document while the module is
called 'External Timing'? Seems to be no ideal example for 'External
Timing'?

A: Timesheet illustrates internal timing because the synchronization
information is not included in the elements to be timed. Nevertheless, the
specification now also includes an informative example outside XHTML. The
example is the following:

---- example.xhtml
<xhtml xmlns="http://www.w3.org/1999/xhtml"
 xmlns:smil="http://www.w3.org/ns/SMIL30">

 <head>
    <smil:timesheet src="./timesheet.smil"/>
</head>

----timesheet.smil
<smil:timesheet xmlns="http://www.w3.org/ns/SMIL30">
 <smil:seq>
   <smil:item select=".Slide1" dur="5s" />
   <smil:item select=".Slide2" dur="5s" />
   <smil:item select=".Slide3" dur="5s" />
 </smil:seq>
</smil:timesheet>
---------------------------------------------------------------

5.------------------------------------------------------------
Q: typo?

'<!DOCTYPE htmlLIC "-//W3C//DTD XHTML 1.0
Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">'?

A: Yes. In fact in the examples we have removed DOCTYPE, because we are 
using namespaces
-------------------------------------------------------------------

6.-----------------------------------------------------------------
13.7.2
'The following example illustrates how the animate element can be used to
animate CSS attributes of elements of the host language.

<smil:timesheet>
  <seq>
   <item select=".Slide" dur="15s">
      <par>
         <item select=".Bullet" beginInc="3s">
            <animate select=".Bullet" attributeName="marginLeft"
values="200;0" dur="1s" />
         </item>
      </par>
   </item>
  </seq>
</smil:timesheet>

-> CSS properties or really attributes? If attributes reference an example
language...
-> 'attributeName="marginLeft"' which language has a CSS property
'marginLeft'?
If this is defined in SMIL, this is maybe a good indication to reference
the definition here again ;

A: Yes; the word “property” is now used instead of “attribute”. In
addition, the example has been modified in order to include the
attributeType to CSS (see 3.6.1, Animation module in SMIL). Finally,
"margin-left" is used instead of marginLeft.

<smil:timesheet>
   <smil:seq>
      <smil:item select=".Slide" dur="15s">
         <smil:par>
            <smil:item select=".Bullet" beginInc="3s">
               <smil:animate select=".Bullet" 
                     attributeName="margin-left" 
                  attributeType =”CSS” values="200;0"dur="1s" />
            </smil:item>
         </smil:par>
      </smil:item>
   </smil:seq>
</smil:timesheet>
--------------------------------------------------------------

7.-----------------------------------------------------------
Q: 13.8
Index Function
-> Add required title element to the XHTML example...

-> wrong/senseless structure or example:

'<head>
<!DOCTYPE htmlLIC "-//W3C//DTD XHTML 1.0
Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:smil="http://www.w3.org/2007/07/SMIL30/Timesheets">
<head>
<smi:timesheet>
<par>
<excl>

A: this is the same error as pointed out before. The specification has
been modified by removing DOCTYPE, because we are  using namespaces.
--------------------------------------------------------------

8.------------------------------------------------------------
-> missing required alt attribute in img elements, if they are from XHTML
as indicated in the example

A: Yes, the alt attribute has been added in SMIL 3.0;
<body>
  <img alt=”image1” src="Image1.jpg" class="Image" id="Image1" />
  <img alt=”image2” src="Image2.jpg" class="Image" id="Image2" />
  <img alt=”image3” src="Image3.jpg" class="Image" id="Image3" />
  <img alt=”image4” src="Image4.jpg" class="Image" id="Image4" />
  <img alt=”image5” src="Image5.jpg" class="Image" id="Image5" />
</body>
-----------------------------------------------------------------

9.---------------------------------------------------------------
-> a practical problem with this example is, that the large images are all
loaded with the document at once, therefore the thumbnails are useless, if
all images are loaded anyway, this is ineffective for the purpose of an
image gallery and from the point of produced traffic, because the user
expects to have a choice to choose and load an image or not...

A: Timesheets/smil includes the prefetch module for controlling the
prefetching of elements. However, the purpose of this example is not to
show how prefetching works (explained in 4.5 The SMIL 3.0 PrefetchControl
Module), and thus is not used in this example.

An example on how to use the prefetch control module is now provided in
the specification:
<head>
    <smil:timesheet>
      <smil:seq>
        <smil:prefetch select="#Image1" mediaSize="100%" />
        <smil:par>
          <smil:item select="#Image1" dur="5s" />
          <smil:prefetch select="#Image2" />
        </smil:par>
        <smil:par>
          <smil:item select="#Image2" dur="5s" />
          <smil:prefetch select="#Image3" />
        </smil:par>
        <smil:par>
          <smil:item select="#Image3" dur="5s" />
          <smil:prefetch select="#Image4" />
        </smil:par>
        <smil:par>
          <smil:item select="#Image4" dur="5s" />
          <smil:prefetch select="#Image5" />
        </smil:par>
        <smil:item select="#Image5" dur="5s" />
      </smil:seq>
    </smil:timesheet>
  </head>
  <body>
   <div id="Images">
    <img src="img/Image1.jpg" alt="Image1" class="Image" id="Image1"/>
    <img src="img/Image2.jpg" alt="Image2" class="Image" id="Image2"/>
    <img src="img/Image3.jpg" alt="Image3" class="Image" id="Image3"/>
    <img src="img/Image4.jpg" alt="Image4" class="Image" id="Image4"/>
    <img src="img/Image5.jpg" alt="Image5" class="Image" id="Image5"/>
    </div>
  </body>

----------------------------------------------------------------

10.------------------------------------------------------------- 
Q: General:

- why not to use an XML processing instruction to reference the timesheet
as a stylesheet?

<?xml-stylesheet href="timesheet.smil" type="application/smil+xml"
title="a timesheet" alternate="yes" ?>

then it is not needed to use another namespace in the XHTML-document and
it is possible to use it alternatively or additionally to CSS...

As a possible application:

a) example.xhtml contains references to CSS-files and to timesheet-files
either with xml-stylesheet processing instructions or the link element.
b) all styling is in external files, some for CSS, some for timesheets,
depending on the processing instruction or the rel attribute of the link
element, the different stylings can be combined or used alternatively.
c) the user/reader can select the desired styling within the user-agent
depending on the defaults of the author or additional selectivity
possibilities of the user-agent

- because the author has not to mix different XMLs in one document and
does not have to put SMIL code directly into the main document, the
document still validates with an 'ordinary' validator or in the case of
XHTML can still be served as text/html for backwards accessibility, if an
outdated viewer is not able to interprete application/xhtml+xml.

A: XML namespaces define a way to mix different XML-based languages. The
specifications now includes an example of how to include external (as an
external document) timesheets in an XHTML document by using the src
attribute. This mechanism allows, for example, the creation of
hierarchical timesheets 
------------------------------------------------------------------- 

11.----------------------------------------------------------------
Q: - example for a complete external document with a timesheet missing

A: The specification now includes an informative example for a complete
external document with timesheet
-----------------------------------------------------------------

12.--------------------------------------------------------------
Q: - is it already planned/done to add ':timed-inactive' to a CSS3
module?
If not, how to use it in a 'valid' CSS-file?

A: this is an error in the document. The text is not valid anymore has
been modified as:

Since SMIL Timesheets only describes the temporal dimension of the
document, it must be integrated with a host language's layout system. It
can be integrated, for example, with CSS based layout by affecting the CSS
properties of the timed elements. For instance, the CSS display property
can be used to control, whether an element is displayed or not. The SMIL
Timesheets processor sets the CSS display property to to "none", when the
timed element should not be visible based on the timesheet. According to
CSS specification, this causes the element to have no effect on the layout
of the document, and thus the element is invisible.
At the same time the original value should be stored for later use. When
the media element should become visible, the original display value can be
restored.

The content authors should be aware that according to the CSS
specification the descendant elements of an element, which has display
value set to none, are also invisible. Therefore, the content authors
should check that all the parent elements of an active elements are also
set active in the timesheet if they are referenced in the timesheet.

Finally, the content authors should also be aware that only visible
elements can increment CSS counters. Therefore, CSS counters might not
work as expected when they are used together with timesheets. One solution
is to use CSS attributes instead and define their values in the document or
increment the attribute values, e.g., using a scripting language.
--------------------------------------------------------------------

----

Received on Wednesday, 24 October 2007 13:36:56 UTC