RE: ISSUE: Changes to Simple Delivery Profile to Allow Use of Other Profiles

Right. While clearly adding Full to a set of profiles makes it maximally taxing to a presentation processor. Adding just CFF and SDP profiles is actually useful signaling IMO.  A pure SDP processor could indeed reject a document that required something in the CFF profile (or indeed any other profile) which is not in the SDP profile; that is the point of the profile as indeed CFF should be a superset of SDP (but see note below).

However my expectation in practice is that one would be able to construct a document that is both CFF conforming and SDP conforming, which does not rely on any more features than SDP, to work on both a conforming CFF processor and a conforming pure SDP processor, and one could apply the two profiles below to indicate same.

[note There is an issue in that the CFF profile (at least v 1.0.3) doesn't seem to use #fontSize or #frameRate (although the text implies frameRate can be specified if it matches the frame rate of the CFF container), and it also uses the base attribute incorrectly. CFF however does not appear to actively prohibit #fontSize and so I believe this would work]


<!--
This references the CFF profile (a conformance requirement for CFF), but then removes the CFF features not required by SDP. It then references the SDP profile (a conformance requirement for SDP).
-->
<ttp:profile use="http://www.w3.org/TR/profile/simple-delivery">
<ttp:profile use="http://www.decellc.org/profile/2012/01/cff-tt">
            <extensions xml:base="http://www.w3.org/ns/ttml/feature/"  xmlns="http://www.w3.org/ns/ttml#parameter">
                        <feature value="optional">#backgroundColor</feature>
                        <feature value="optional">#backgroundColor-region</feature>
                        <feature value="optional">#bidi</feature>
                        <feature value="optional">#direction</feature>
                        <feature value="optional">#display</feature>
                        <feature value="optional">#display-align</feature>
                        <feature value="optional">#display-block</feature>
                        <feature value="optional">#display-inline</feature>
                        <feature value="optional">#fontFamily</feature>
                        <feature value="optional">#fontFamily-non-generic</feature>
                        <feature value="optional">#fontStyle</feature>
                        <feature value="optional">#fontStyle-oblique</feature>
                        <feature value="optional">#fontWeight</feature>
                        <feature value="optional">#fontWeight-bold</feature>
                        <feature value="optional">#length</feature>
                        <feature value="optional">#length-em</feature>
                        <feature value="optional">#length-integer</feature>
                        <feature value="optional">#length-negative</feature>
                        <feature value="optional">#length-pixel</feature>
                        <feature value="optional">#length-real</feature>
                        <feature value="optional">#lineHeight</feature>
                        <feature value="optional">#metadata</feature>
                        <feature value="optional">#nested-div</feature>
                        <feature value="optional">#nested-span</feature>
                        <feature value="optional">#opacity</feature>
                        <feature value="optional">#origin</feature>
                        <feature value="optional">#padding</feature>
                        <feature value="optional">#padding-1</feature>
                        <feature value="optional">#padding-2</feature>
                        <feature value="optional">#padding-3</feature>
                        <feature value="optional">#padding-4</feature>
                        <feature value="optional">#pixelAspectRatio</feature>
                        <feature value="optional">#showBackground</feature>
                        <feature value="optional">#styling-chained</feature>
                        <feature value="optional">#styling-nested</feature>
                        <feature value="optional">#textAlign</feature>
                        <feature value="optional">#textAlign-relative</feature>
                        <feature value="optional">#textDecoration</feature>
                        <feature value="optional">#textDecoration-over</feature>
                        <feature value="optional">#textDecoration-through</feature>
                        <feature value="optional">#textOutline</feature>
                        <feature value="optional">#tickrate</feature>
                        <feature value="optional">#timebase-media</feature>
                        <feature value="optional">#time-clock-with-frames</feature>
                        <feature value="optional">#timeContainer</feature>
                        <feature value="optional">#time-offset-with-frames</feature>
                        <feature value="optional">#time-offset-with-ticks</feature>
                        <feature value="optional">#unicodeBidi</feature>
                        <feature value="optional">#visibility</feature>
                        <feature value="optional">#visibility-block</feature>
                        <feature value="optional">#visibility-inline</feature>
                        <feature value="optional">#visibility-region</feature>
                        <feature value="optional">#wrapOption</feature>
                        <feature value="optional">#writingMode</feature>
                        <feature value="optional">#writingMode-horizontal</feature>
                        <feature value="optional">#writingMode-horizontal-rl</feature>
                        <feature value="optional">#writingMode-vertical</feature>
                        <feature value="optional">#zindex</feature>
            </extensions>
</ttp:profile>

From: Monica Martin (MS OPEN TECH) [mailto:momartin@microsoft.com]
Sent: 18 September 2012 16:51
To: Michael A Dolan; public-tt@w3.org
Subject: RE: ISSUE: Changes to Simple Delivery Profile to Allow Use of Other Profiles

A bit confusing Michael. None of the added text in Sections 1 or 5.4.2 is a conformance requirement. The addition of ttp:profile element was to correct an omission in Section 5.2.2.  Use of multiple ttp:profile is allowed by TTML 1.0.[1]

I can see we could remove this text in Section 5.4.2 Note:  "See also Conformance<http://dvcs.w3.org/hg/ttml/raw-file/tip/ttml10-sdp-us/Overview.html#conformance>."

Monica

[1] Section 5.2
The profile of TTML that must be supported by a TTML content processor in order to process a document instance is specified either (1) by specifying attp:profile attribute on the root tt element, as defined by 6.2.8 ttp:profile<http://www.w3.org/TR/2010/REC-ttaf1-dfxp-20101118/#parameter-attribute-profile>, or (2) by including one or more ttp:profile elements in the head element, in accordance with 6.1.1 ttp:profile<http://www.w3.org/TR/2010/REC-ttaf1-dfxp-20101118/#parameter-vocabulary-profile>.

From: Michael A Dolan [mailto:mdolan@newtbt.com]
Sent: Tuesday, September 18, 2012 9:48 AM
To: public-tt@w3.org
Subject: RE: ISSUE: Changes to Simple Delivery Profile to Allow Use of Other Profiles

I am concerned that this proposal perpetuates a misunderstanding about TTML profiles.  Profiles are metadata signaling to the Presentation Processor about what features are minimally required to properly render the document.  They are not, at least not directly, a signal for document conformance.

With the current definition in TTML, I'm not sure what value there is (and I can see serious downsides) to signaling, for example, all of the following profiles:

SDP-US
CFF-TT
DFXP-Full

The proper interpretation of the above, by virtue of the DFXP-Full, would be that a Presentation Processor would need to support every single TTML feature in order properly render such a document.

I'm pretty sure that's both not the intent of this proposal and obviously harmful as an SDP-US Presentation Processor would be permitted to reject the document.

If we want the profile to signal document conformance instead of required presentation processor features, we need to make substantive changes to the TTML 1.0 spec to change the definition of profile.

I'm OK with that change. But we can't implement this proposal without first doing that.

Regards,

                Mike

From: Monica Martin (MS OPEN TECH) [mailto:momartin@microsoft.com]<mailto:[mailto:momartin@microsoft.com]>
Sent: Tuesday, September 18, 2012 9:24 AM
To: 'public-tt@w3.org'; Michael A Dolan (mdolan@newtbt.com<mailto:mdolan@newtbt.com>); Sean Hayes
Subject: ISSUE: Changes to Simple Delivery Profile to Allow Use of Other Profiles

Issue: Allow more than one profile to be used in the SDP-US. Add use of ttp:profile element.

Benefit: Allows SDP-US to use TTML 1.0<http://www.w3.org/TR/2010/REC-ttaf1-dfxp-20101118/>, SDP-US profile URI, and other profiles.  TTML 1.0 already defines the mandatory processing semantics for the intersection of required elements of the profile(s) that apply (Section 5.2<http://www.w3.org/TR/2010/REC-ttaf1-dfxp-20101118/#vocabulary-profiles>).[1]

Proposal to add the following:[2]
1. Language in Section 1 that indicates use of other profiles is not precluded; retain URI requirement for this profile.
2. The profile element to the list of elements in R0007, Section 5.2.2.
3. Language in Section 5.4.2 that articulates how multiple profile elements may exist.

We plan to enter into Issue/Tracker. The question was raised by DECE community by Mike Dolan re: CFF-TT.

Thanks. Monica


Monica J Martin
Senior Program Manager
Microsoft Open Technologies, Inc.
A subsidiary of Microsoft Corporation


[1]
TTML 1.0 Section 5.2:  If more than one ttp:profile element appears in a TTML document instance, then all specified profiles apply simultaneously."

[2] Proposed changes (in bold)
Section 1
This constrained profile enumerates a set of required TTML features, some of which may be constrained in behavior, and the capabilities required of a Presentation Processor<http://www.w3.org/TR/ttaf1-dfxp/#conformance-presentation-processor> in TTML 1.0.  The semantics defined in TTML 1.0 apply unless otherwise constrained in this profile.

Claims of conformance MUST use this URI and implement the required features and constraints of use and processing outlined in this profile.

Name

Designator

simple-delivery

http://www.w3.org/TR/profile/simple-delivery<http://www.w3.org/TR/profile/online-delivery>


Conformance to this profile does not preclude the:

*         Use of other features defined in TTML 1.0. Such behavior is not defined here.

*         Use of other profiles that may implement the features in this profile.

Section 5.4.2
Add to Note (1). NOTE: See also Conformance<http://dvcs.w3.org/hg/ttml/raw-file/tip/ttml10-sdp-us/Overview.html#conformance>.  TTML 1.0 allows zero or more profiles (ttp:profile in the head element) to be specified and used simultaneously. A player may reject documents it does not understand.

Add to Note (2). NOTE: When the use attribute is used on the ttp:profile element, the use attribute could indicate the geographical region for which the profile is used. For example, specific styling capabilities could be used in a particular geographical region. See also Other Constraints<http://dvcs.w3.org/hg/ttml/raw-file/tip/ttml10-sdp-us/Overview.html#other_constraints>.

Requirement R0007
Add ttp:profile element to the list.