W3C home > Mailing lists > Public > public-cdf@w3.org > January 2007

Re: Comments on "WICD Full/Mobile 1.0"

From: Chris Lilley <chris@w3.org>
Date: Wed, 24 Jan 2007 17:53:38 +0100
Message-ID: <1148264454.20070124175338@w3.org>
To: public-cdf@w3.org
Cc: Björn Höhrmann <derhoermi@gmx.net>

Hello public-cdf,

In this message
Bjoern wrote:

>   I've looked at http://www.w3.org/TR/2005/WD-WICDFull-20051219/ and
> http://www.w3.org/TR/2005/WD-WICDMobile-20051219/ and I think the
> requirements
>   * For accessibility, conforming user agents should profile the
>     option of switching off audio.
> to the extend that they make sense should be moved to "WICD Core 1.0"

We agree and this is now in WICD Full, with revised wording:

The use of "profile the option" was indeed confusing. It had noting to
do with profiles. It wass saying the user agent should allow the user to
set an option in their client so that audio does not play by itself
automatically. Instead they are told that there is audio and given the
option to play it if they want. Here is what UAAG actually says:


3.2 Toggle audio, video, animated images (P1)

  Allow configuration not to render audio, video, or animated image
  content, except on explicit user request.

We have therefore moved the requirement from WICD Full to WICD Core as
you suggest, and expressed it using the same wording as UAAG does,
including a link to UAAG section 3.2.

>   * For accessibility, conforming user agents must provide the
>     option of pausing, rewinding, or stopping video. 

This is similar to A) and again occurred with identical wording in Mobile
and Full. We have moved it to Core as you suggest.

The relevant quote from UAAG is

4.4 Slow multimedia (P1) 

4.5 Start, stop, pause, and navigate multimedia (P1)

The revised wording to address your comments A and B is thus:


  4.4 Child content accessibility guidelines

  For accessibility, conforming WICD Core 1.0 user agents must provide
  the option of pausing, rewinding, or stopping video. See section 3.2
  of [User Agent Accessibility Guidelines 1.0].

  For accessibility, conforming WICD Core 1.0 user agents must allow
  the user to slow the presentation rate of rendered audio and
  animation content (including video and animated images). See section
  4.4 of [User Agent Accessibility Guidelines 1.0].

  For accessibility, conforming WICD Core 1.0 user agents must allow
  the user to stop, pause, and resume rendered audio and animation
  content (including video and animated images) that last three or
  more seconds at their default playback rate. They must also allow
  the user to navigate efficiently within rendered audio and
  animations (including video and animated images) that last three or
  more seconds at their default playback rate. See section 4.5 of
  [User Agent Accessibility Guidelines 1.0].

> and the requirements for JFIF, JPEG, PNG support should be spelled out
> by changing "WICD Core 1.0" such that any supported bitmap format must
> be supported from both XHTML and SVG content; support for the formats
> would then be required through requirements in SVG.

Note that JPEG is a compression technique and JFIF is a file format that
uses the JPEG compression technique. JPEG/JFIF is the correct way to
refer to what everyone nowadays calls "JPEG files". Your comment
appears to indicate that there are three separate formats.

You seemed to be asking for XHTML to support all raster image formats that
SVG supports (currently PNG and JPEG/JFIF) rather than explicitly
listing them.

We could have gone either way on this.  A slight advantage for doing it by
reference is that if SVG ever adds more formats or removes them, WICD
stays in sync. A stronger argument for explicitly listing them is that
it is clearer and easier to read.

In the end we decided to simply state that PNG and JPEG/JFIF must be
supported in XHTML for WICD Core compliance. Its straightforward and
easy to test. The revised wording is:


  4.1 Raster formats

  The viewer must support JPEG/JFIF [Scalable Vector Graphics (SVG)
  Tiny 1.2 Specification], PNG [Portable Network Graphics (PNG)
  Specification (Second Edition)] and GIF 89a (non-interlaced,
  non-transparent, non-animated) raster image formats. Other image
  formats may be supported in addition. For PNG, all color types and
  bit depths shall be supported, gamma correction shall be supported,
  and any alpha or transparency information shall be used to composite
  the image onto the background.

> Both documents can then be reduced to plain lists (as opposed to the
> current line and section noise with confusing inline requirements and a
> weird conformance section) of what must be supported by compliant user
> agents.

Common factors between Mobile And Full have been moved to Core, and
places where is is different remain in the individual profiles.

> The requirements for content do not make much sense to me; frankly, what
> should it say? That you can use any audio format you like, but if you
> use script it must be ECMA-262 compliant? That would not make much
> sense.

It would be great to mandate a particular audio format, but
a) the RF ones are not universally implemented, especially on Mobile
b) Mobile platforms have by and large already picked their supported
audio and video formats, mostly from MPEG and thus not RF.

However, just because we can't mandate a format for one area does not
mean that we don't for other areas (raster images, scripting languages).


> There are some related problems here, for example, "WICD Full 1.0"
> notes "A conforming style language is CSS" and that implementations
> must support that, the specification then also says CSS 2.1 is re-
> quired,

The wording "conforming style language is CSS" no longer appears in
the document. The individual profiles define the level and profile of
CSS as appropriate, for example WICD Mobile says

  Conformant WICD Mobile 1.0 user agents must support the updated
  version of CSS Mobile Profile 1.0.

while WICD Full says

Conformant WICD Full 1.0 user agents must support Cascading Style
Sheets, level 2 revision 1 [CSS21] specification.


> and "WICD Core 1.0" requires CSS Media Queries support; I do
> not really think it would make sense to define a CSS 2.1 + CSS3MQ
> CSS profile specifically for "WICD Full 1.0" conformance.

Media queries is discussed in another comment and not considered here.


> "WICD Mobile 1.0" is confused about whether ECMA-262 or ECMA-327 must
> be supported. 

The current text, in the references, is

ECMAScript Language Specification 3rd Edition

    ECMAScript Language Specification 3rd Edition , European Computer
    Manufacturers Association, December 1999. Also available as
    ISO/IEC 16262:2002


> "WICD Mobile 1.0" 3.3.1 clarifies the semantics of the 'handheld' media
> type, I do not think this is "CDR"-specific in any way, this text should
> be moved to the specifications that define the semantics of this type.

The current text is in WICD Core

  A user agent that discovers a CSS style sheet, provided for its own
  device class (either by media attribute - for instance set to
  "handheld" - or by a Media Query expression), should assume the
  content was created with specific properties "in mind". The agent is
  then expected to deactivate any custom adaptation techniques (for
  example rendering wide screen content on a narrow screen) and
  display the intended layout "as is".

This does not define, or redefine, the semantics of the CSS 'handheld'
media type.


> I don't think the resulting documents really merit separate technical
> reports, and I am not really convinced there is much value in having
> special terms for user agents that implement the specified set of
> features.

The Working Group has moved items which are genuinely common to all WICD
profiles to WICD Core, retaining profile-specific information in the
actual profiles.

Both content conformance and user agent conformance is specified via the
individual profiles, which in turn reference the Core. We are informed
by content providers, operators, and handset manufacturers that the
resultant labelling does indeed have value.

Please let us know shortly if these changes do not address your

 Chris Lilley                    mailto:chris@w3.org
 Interaction Domain Leader
 Co-Chair, W3C SVG Working Group
 W3C Graphics Activity Lead
 Co-Chair, W3C Hypertext CG
Received on Wednesday, 24 January 2007 16:53:58 UTC

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