<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]-->
<title>Re: [mpeg-OTspec] Toward a Composite Font format specification</title>
<style>
<!--
/* Font Definitions */
@font-face
{font-family:PMingLiU;
panose-1:2 2 5 0 0 0 0 0 0 0;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:"\@PMingLiU";
panose-1:2 2 5 0 0 0 0 0 0 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page Section1
{size:612.0pt 792.0pt;
margin:70.85pt 2.0cm 2.0cm 2.0cm;}
div.Section1
{page:Section1;}
/* List Definitions */
@list l0
{mso-list-id:416947816;
mso-list-template-ids:1466857356;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-GB link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Daniel,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Next to the two cases you mention there is a third case<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>(C) the standard specifies both (A) and (B) and the implementer
declares to what his implementation conforms with (only (B) or also (A)).<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I entirely support your view to be factual and consider use
scenarios in order to decide whether (B) is needed. If it is you may like to
consider my option (C) <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Leonardo <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>
<p class=MsoNormal><b><span lang=EN-US style='font-family:"Tahoma","sans-serif"'>From:</span></b><span
lang=EN-US style='font-family:"Tahoma","sans-serif"'> Daniel Strebe
[mailto:dstrebe@adobe.com] <br>
<b>Sent:</b> 22 September 2009 23:31<br>
<b>To:</b> leonardo@chiariglione.org; Levantovsky, Vladimir; Ken Lunde;
mpeg-OTspec@yahoogroups.com<br>
<b>Subject:</b> Re: [mpeg-OTspec] Toward a Composite Font format specification<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><span style='font-size:18.0pt'><o:p> </o:p></span></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:16.0pt;
font-family:"Calibri","sans-serif"'><br>
Leonardo:<br>
<br>
Thank you for your considered comments. As with Vladimir’s, I do not
disagree with what you say, but merely with the applicability. Let me try again
from a different angle.<br>
<br>
The dispute is not over how to write the specification or its language. It is
not about “shall” versus “should”. The dispute is over
what it is we are specifying.<br>
<br>
I argue we should limit the purview of this specification to the grammar and
semantics of composite font recipes. Within the limits of this purview, I agree
entirely with your comments, as well as with their applicability. We need an
incisive specification, and we should do what we can to “enforce”
it and to insulate it from deviant industry practices.<br>
<br>
As I understand Vladimir’s argument, the purview of the specification
should, further, require consumers to realize some subset of the functionality
described by the semantics of composite font recipes. This body would decide
upon the subset.<br>
<br>
I oppose broadening the purview. My greatest reason is that to broaden the
purview would subject this specification to the very corrupting forces you
describe — starting with us. I do not anticipate we will be able to
identify some universally useful subset of a composite font for us to mandate.
Therefore conjuring up one will only weaken the specification: Because the
mandatory subset will not suit anyone in particular, everyone will feel
motivated to violate it. I have challenged Vladimir to explain how we could
create a mandatory subset that would not be arbitrary.<br>
<br>
That argues that we must either (A) require consumers to realize the entire
functionality of a composite font recipe; or (B) not require consumers to
realize any particular subset of functionality.<br>
<br>
(A) is not satisfactory because we know of many circumstances where consumers
do not need the complete functionality offered by the semantics of composite
font recipes. Presumably there are many more we do not know about.<br>
<br>
(B) is... satisfactory? —as long as it does not cause interoperability
problems. I have asked Vladimir, and I invite anyone else as well, of course,
to identify specific scenarios that will be problematic. So far in our
discussions, none have been forthcoming. Having pondered a lot of scenarios
myself, I doubt any important ones exist. I think identifying such scenarios
should be the thrust of the conversation.<br>
<br>
Please understand I do not argue from ideology. If, for example, we had decided
that the purpose of this specification is ONLY to communicate a synthesis of
multiple (available) OpenType fonts for the purpose of typographic fidelity,
then I would turn full circle and advocate mandating that consumers implement
the entire functionality of the specification in order to claim conformance.
But that is not what we have decided. We recognize diverse uses for composite
fonts, and we are stuck with the reality that component fonts may not be
available or may be available in forms that deviate in various ways from the
knowledge of the creator. These considerations necessarily change what we must
consider to be the purview of the specification. If we do not adapt the purview
of the specification to the situation we face then we will write a poor
specification and we will invite implementers to flout it.<br>
<br>
We seem to agree on the need, purpose, and structure of a specification. We do
not seem to agree on what it is we are specifying.<br>
<br>
Regards,<br>
<br>
— daan Strebe<br>
Senior Computer Scientist<br>
Adobe Systems Incorporated<br>
</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><br>
<br>
On 09/09/22 8:44, "Leonardo Chiariglione" <<a
href="leonardo@chiariglione.org">leonardo@chiariglione.org</a>> wrote:</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif"'>Daniel,<br>
I have been following the discussions of the group and I feel compelled to
intervene at this stage.<br>
First of all a standard is about documenting an agreement by parties interested
in suing the agreement. Therefore I understand the language “shall”
in a standard, while I do not understand “should” (when? Every
other day? When you feel like that?).<br>
I entirely concur that MPEG and ISO are not in the business to enforce a proper
use of their standards. What MPEG provides is <br>
1. instructions on what people should do to implement a
standard (the standard itself) <br>
</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><br>
</span><span style='font-size:14.0pt;font-family:"Calibri","sans-serif"'>2.
the means for a third party to assess whether a claimed
conformance statement is indeed to be taken as good.<br>
</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><br>
</span><span style='font-size:14.0pt;font-family:"Calibri","sans-serif"'>I can
understand that in some cases implementers want to keep the right to make their
own implementations that do not contain the set of tools that is written in the
standard. This has happened in the past and will continue (alas) to happen in
the future. In a recent major case we changed the standard to accommodate
industry practices, but at the same time posted the MPEG Vision (<a
href="http://www.chiariglione.org/mpeg/visions/mpeg/index.htm">http://www.chiariglione.org/mpeg/visions/mpeg/index.htm</a>)
where there is a non-so-subliminal message that we will not do it again.<br>
I can understand that there are industries with different traditions and that
some people want to retain freedom to use standards the way they want. I have nothing
against that. I just would like to say that in a convergence age the
established freedoms of an industry may clash with the tenets of another
industry and that it may be so that, in the convergence process, the second
industry has more leeway.<br>
I would encourage people to say now what they want from the standard instead of
reserving the right to take freedoms in the future. It is easy to write one
page more or add another conformance point now, instead of having millions of
clients with no status.<br>
As we said in the MPEG vision we are not going to change our standards to suit
those who take liberties with hem…<br>
Leonardo <br>
<br>
<br>
</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><br>
</span><b><span style='font-size:10.0pt;font-family:"Calibri","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Calibri","sans-serif"'> <a
href="mpeg-OTspec@yahoogroups.com">mpeg-OTspec@yahoogroups.com</a> [<a
href="mailto:mpeg-OTspec@yahoogroups.com">mailto:mpeg-OTspec@yahoogroups.com</a>]
<b>On Behalf Of </b>Daniel Strebe<br>
<b>Sent:</b> 22 September 2009 03:30<br>
<b>To:</b> Levantovsky, Vladimir; Ken Lunde; <a
href="mpeg-OTspec@yahoogroups.com">mpeg-OTspec@yahoogroups.com</a><br>
<b>Subject:</b> Re: [mpeg-OTspec] Toward a Composite Font format specification<br>
</span><br>
<br>
<span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><br>
<br>
Vladimir,<br>
<br>
Thank you for taking the time to comment on the scenario I contrived. Let me
note first that I do not disagree with anything you wrote, particularly, but
only on the significance. Hence we may be back to a philosophical discussion.<br>
<br>
With regard to your point (3), I agree entirely, but I do not see the
relevance. The inadequate tools presenting themselves to Marina’s team
did not arise out of failures of specification. Specifically they did not come
about as a consequence of a specification failing to describe compliance
criteria. Therefore our prescribing mandatory versus optional portions of a
consumer implementation will not prevent the circumstances Marina’s team
finds itself in.<br>
<br>
Instead, the inadequate tools came about because of gaps in implementation, if
we wish to judge unkindly. But a more realistic view is that those who
developed the tools judged that the market for a fuller implementation would
not reward the effort needed. It means little to for us to chide the browser
developers for not even kerning their text—and yes, that is the present
state of affairs with all browsers except Firefox on Macintosh—when there
is no practical mechanism available for a Web designer to display body text in
the font of her choice. It is the market that determined how much effort Web
browser developers were willing to invest into compliance, not the
specification. When the market conditions change, browser implementations will
change.<br>
<br>
The same goes for Marina’s team. You are correct to note that they would
not have to do the work later if they implemented the specification according
to our standards, but that is almost never anyone’s goal, and
shouldn’t be. The only time it makes sense to delay putting out a product
in order to add potential future functionality is if the cost of doing it later
would overwhelmingly exceed the cost of doing it now. That would never be the
case with composite font levels of implementation.<br>
<br>
Our constituency will find themselves in same position. We may elect to gather
together some arbitrary subset of our final specification and call it
“mandatory”, but: (A) I am fairly certain the subset WILL be
arbitrary, meaning not reflecting the needs of any particular market or
consumer; and (B) Whatever we have to say about it will get ignored entirely in
favor of market forces anyway. That will happen for several reasons.<br>
<br>
For one thing, this specification will never carry any sort of marketing
cachet. That is the cold, hard truth. There won’t ever be some emblem on
a box that people will look for with confidence. No company will come to us
begging to certify their implementation so that they gain a market advantage.<br>
<br>
For another, this is not some optical storage medium specification, where the
realities of physics and engineering not only dictate the tolerances that get
written into the specification, but also punish the violators. Our enterprise
is fundamentally different. Composite fonts won’t fail catastrophically
just because someone only implements part of the specification. There are
endless grades of utility. We will not be able to isolate some subset of the
specification and defend that subset as being somehow better or preferable to
some other subset. If so, then why would we do it? More to the point, why would
an implementer bother to follow our implementation requirements if they
perceive an advantage to not following them?<br>
<br>
For yet another, and this is corollary to the last, there isn’t really
any such thing as “interoperability” on the consuming side.
Therefore implementers of composite font consumers won’t feel any
pressure to adhere to recommendations whose ostensible purpose is
“interoperability”. The consumer knows what it’s trying to
achieve when it consumes composite fonts. We do not. Unlike optical media, we
cannot describe the consumer’s precise intent. We cannot say anything so
pithy and absolute as “The consumer wants to read off the disc any of the
information that was recorded onto it, unchanged, now and forever.” All
we can say with any confidence is that the consumer is trying to do something
with fonts (possibly) aggregated into some über-font. What the consumer wishes
to do next with the data it works with is entirely the consumer’s
purview, not ours.<br>
<br>
More specifically, If the consumer writes a PDF, the consumer is going to want
to write one according to how it used the composite fonts, not how we thought
it might want to use them. Therefore our argument for interoperability would
fail. If the consumer wishes to put out text in some interchange format, it may
consider its own usage to be idiosyncratic and specific to its own
circumstances, and therefore may pass on the composite font recipe in its
original form. Or, like the PDF case, the consuming application may be
directing downstream consumers to retain fidelity to its own document
presentation, and therefore the consuming application may write out the subset
of the composite font recipe that it made use of while discarding the rest.
“Interoperability” here is, again, a decision we cannot make for
the consumer because we know nothing about the consumer’s intent.
Therefore we cannot be in the business of telling consumers this or that is
mandatory versus optio nal.<br>
<br>
We must focus our efforts on the communication of the intent. Seeing to it that
consumers fulfill the intent is not our business. We have no means to enforce
it, no way to divine the consumer’s intent or business, no realistic
expectation we will be heeded if we try. <br>
<br>
Meanwhile it is in everyone’s interest to adhere to the specification of
recipes. That the part we should focus on and get right. We do not have to make
any arbitrary decisions for anyone in specifying this language for
communication. Everyone will be happy if the intent can be specified as
precisely as needed.<br>
<br>
So. If I may make some requests, I would like you to address three matters
specifically:</span><o:p></o:p></p>
<ol start=1 type=1>
<li class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;
mso-list:l0 level1 lfo1'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>What
do you mean when you talk about “interoperability”? What
scenarios will fail if consumers are allowed to decide their own level of
implementation, versus our deciding what is mandatory and what is
optional? </span><o:p></o:p></li>
<li class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;
mso-list:l0 level1 lfo1'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>How
will our decisions on “mandatory” versus
“optional” be defensible as anything better than arbitrary? </span><o:p></o:p></li>
<li class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;
mso-list:l0 level1 lfo1'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>You
stated that, if the consumer did not claim “compliance” with
the specification, that no harm would be done in only partially
implementing the specification. Do you believe this specification will
become so important that overt statements of compliance will carry market
weight? (I would argue even OpenType does not carry such weight. Products
merely state they can use OpenType fonts and what kinds of things they can
do with them; nobody claims “compliance”.) If it does not
carry market weight, what would be the motive for a developer to implement
more than they believed their application needed just to be able to claim
“compliance”? </span><o:p></o:p></li>
</ol>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><br>
<br>
Regards,<br>
<br>
— daan Strebe<br>
Senior Computer Scientist<br>
Adobe Systems Incorporated<br>
<br>
<br>
On 09/09/21 14:52, "Levantovsky, Vladimir" <<a
href="Vladimir.Levantovsky@MonotypeImaging.com">Vladimir.Levantovsky@MonotypeImaging.com</a>>
wrote:<br>
Daan,<br>
<br>
Thank you for presenting a very elaborate use case, I really appreciate it. It
brings attention to some very specific details but, first and foremost, I think
it will by and large help us better understand the concepts of mandatory
features in a specification language; and, in particular, it may help us better
understand the scope and goals of the Composite Fonts specification.<br>
<br>
First of all, I would like to make sure we are all on the same page when it
comes to the meaning of the notion of “mandatory” or
“required” components in a specification – they exist and are
useful only for the purposes of defining the meaning of “compliant
implementation” and establishing certain conformance points. There is no
such thing as ‘standards police’, and “violation” of a
specification by not following its recommendations or requirements (and/or not
implementing everything that is deemed mandatory) does not result in any
repercussions for the implementer. In the worst case, the only
“punishment” for not following the spec mandate may be inability to
claim compliance with that standard, and in some circumstances, being compliant
to the spec may bring certain market advantages (e.g. an opportunity to use a
spec logo to promote a final product). Some standards organizations (e.g. those
that define h ardware-acceleration or software development APIs) and their
specifications are very rigid about “enforcing” the conformance
requirements by mandating implementers to run and pass a standardized test
suite as part of self-certification process. Sometimes, they even require to
submit the test results to be validated by a standards organization, e.g. in
exchange for a grant to use its logo on a final product. However, in many cases
implementers are free to make their own choices whether or not to follow all
specification requirements – the result of creating a non-compliant
implementation may be justified by the market conditions. <br>
<br>
For example, if I wanted to build a closed-circuit digital video surveillance
system using MPEG-4 AVC video standard – I may choose not to implement
some video compression/decompression tools that would be mandatory for a
Blu-Ray DVD player. My video surveillance system may work just fine without
them, and I’d have no need or intention to claim that my video
encoding/decoding capabilities are compliant with the standard that all DVD
players must adhere to. To summarize – I’d only have to implement
all mandatory parts of the standard if I<br>
- need to be compliant to pass
a standardized conformance test, and/or<br>
<br>
- want to advertize my product
as compliant with a particular standard.<br>
<br>
<br>
Now, let’s go back to the use case you presented:<br>
<br>
1) The team of developers decided to create a
“rich internet application (RIA)” client where its sole purpose is
to render interactive online map. They concluded that “the project has no
need for VDMX, vhea, vmtx, BASE, JSTF, chunks of GSUB and GPOS, and several
other tables and portions thereof. They will never mix two scripts on the same
line, so they do not care about relative baselines. They lay out no vertical
text. They will never lay out a complete sentence. They do not need punctuation
in any general sense. The slightly different aspect ratios of some of the
components do not concern them because they do not mix text of the different
component fonts on the same line.“ Based on the facts you presented, I
think that it would be fair to say that the RIA client has very limited scope.
Therefore, implementing a limited subset of Composite Fonts specification may
satisfy their needs even though the RIA developers would never be able ( and
likely would have no intention) to claim compliance with the standard. And, if
they don’t claim a conformance to the spec, there is no harm done and
there is no authority that would be in a position to “punish” them.<br>
<br>
<br>
<br>
2) Let’s assume that the RIA team has been
successful in delivering everything they planned for, and their very next step
would be to build on their own success and enhance their application by accommodating
end-user suggestions to introduce a new feature – e.g. displaying a
paragraph of text with ethnic data when an end-user clicks on the name of the
ethnic group or their territory on the map. The RIA team may suddenly realize
that they do need to support punctuation and lay out complete sentences, and be
able to mix two scripts on the same line because “the place names [and
now the description text should] be presented in the script of the
viewer’s choice, they will also be presented in the official script or
scripts of the jurisdiction of the place name.” All of a sudden,
“the grad student tasked with the typography discovers that the <span
style='color:#1F497D'>[newly developed]</span> RIA framework’s support
for typography is no better than a typical Web browser’s”, and that
the industry experts who wrote Composite Fonts specification did have a point
when they said that certain features defined by the standard must be supported
by all implementations.<br>
<br>
In fact, this is another important role of the standards specifications –
many implementers do not possess the same level of expertise in a particular
field (as spec authors do), and they rely on industry / international standards
to provide clear guidance and specify the set of requirements that must be
satisfied to make their implementations compliant and useful.<br>
<br>
<br>
<br>
3) This use case brings even more important aspects to
consider. “Marina is a university professor with a grant from her
government to develop a detailed, interactive online ethnographic map of the
world … Marina concludes they [place (and ethnic group) names] must get
rendered real-time. Because the server budget is limited, she realizes much of
the processing must be client-side. <b>She is unable to meet all her objectives
with any technology that delivered content through the browser</b>”.
(emphasis is added).<br>
<br>
The developers of RIA client wouldn’t have been in a position where
they’d have to develop their own text processing engine with such a
limited scope if they had a choice of standard-compliant text rendering
implementations that are either readily available or simply supported by a
platform of their choice. And, assuming that browser vendors had followed the
standards as well, Marina might have come to a different conclusion that the
existing infrastructure of standards-compliant solutions would provide her with
everything she needs to develop and deploy valuable new content and service
– with minimal efforts, no market fragmentation introduced by a custom
RIA client, and without any need for custom development (all this while saving
government’s and taxpayer’s money!).<br>
<br>
<br>
<br>
Regards,<br>
Vladimir<br>
<br>
<br>
</span><span style='color:white'><br>
</span><span style='font-size:10.0pt;font-family:"Calibri","sans-serif"'>No
virus found in this incoming message.<br>
Checked by AVG - www.avg.com<br>
Version: 8.5.409 / Virus Database: 270.13.110/2385 - Release Date: 09/20/09
17:51:00</span><o:p></o:p></p>
<p><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>No virus
found in this incoming message.<br>
Checked by AVG - www.avg.com<br>
Version: 8.5.409 / Virus Database: 270.13.112/2387 - Release Date: 09/22/09
05:51:00</span><o:p></o:p></p>
</div>
</body>
</html>