W3C home > Mailing lists > Public > public-html-media@w3.org > June 2014

Re: MSE and in-band track registries

From: Aaron Colwell <acolwell@google.com>
Date: Fri, 6 Jun 2014 16:40:38 -0700
Message-ID: <CAA0c1bD-L4OQCToD2+X3_8fzDFBvgoLT3MhB8hPUW0gousrUUQ@mail.gmail.com>
To: Sam Ruby <rubys@intertwingly.net>
Cc: public-html <public-html@w3.org>, "<public-html-media@w3.org>" <public-html-media@w3.org>
Hi Sam,

Comments inline...

On Fri, Jun 6, 2014 at 1:33 PM, Sam Ruby <rubys@intertwingly.net> wrote:

> After initially recommending that In-Band registry follow the lead of MSE,
> the co-chairs discovered three problems.
> The first, and most easiest to solve, is that we don't have a lightweight
> process for updating dated specifications published on the web site.  This
> is the subject of an open bug on MSE[1].
> The second is that the registry points to W3C specifications with MUST
> requirements, and these specifications themselves have not gone through the
> IPR process.  While this was previously overlooked, now that it is known it
> will need to be cleared with the Director.

What IPR issues do you expect here? These specs simply put constraints on
what structures can exist in existing container formats and define how
structures in the bytestreams map to MSE concepts. Don't the IPR issues
only come into play if someone tries to implement a specific format?

> Presuming that is OK with the Director, we will need to ensure that no
> reference from MSE or HTML 5.0 to the registry does so as a normative MUST.

Why? The intent of the registry is to mandate required mimimal behavior for
specific byte stream formats. An implementation does not have to support
all of the formats in the registry, but if it claims to support one of the
specified mimetypes, then it must do so according to the requirements in
the byte stream format spec. This is intended to facilitate

> This lead us to conclude that the "microformats wiki existing-rel-values
> page" reference in HTML5 Section  "Other link types" [2] was a
> better example to follow.  This material is characterized by the following
> characteristics:
> a) the referenced material is on a wiki which makes it easy to update,
> b) the reference to the registry (wiki) itself is Informative,
> c) the referencing text uses the MAY term when pointing to the material in
> the registry (wiki)."
> This leads to the following recommendations:
> MSE:
> 1. Change the text in Section 12 to use MAY (or at most SHOULD) instead of

The musts are there to ensure that the byte stream format specs contain the
necessary information and constraints to be useful in the MSE context.
Weakening these statements makes it difficult to determine whether the
specs meet the minimum bar for usage w/ MSE.

> 2. Keep the MSE reference to the registry as Informative rather than
> Normative.
This is a noop right?

> 3. Move the registry itself [3] and its referenced documents to wiki pages
> (thus resolving bug 25581), and update the MSE specification to point to
> the new registry wiki page.
This came up in the original CR meeting and it was deemed that the wiki
wasn't "versioned/stable" enough which is why we had to snapshot the
documents at CR time. Does this mean that opinion has been reversed? If so,
then why is a wiki better than simply using the Mercurial repository where
the editor's draft version of the registry lives today?


> In-Band:
> 1. Ensure that all references to the registry use MAY (or at most
> SHOULD) instead of MUST.
> 2. Keep the reference as Informative.
> 3. Move the registry itself[4] to a wiki page, and update the HTML5
> specification to point to the new page.
> We believe the In-Band changes can be done during the upcoming HTML 5.0 LC.
> Should the Director not be OK with the specs pointed to by the registries
> containing MUST statements, we will determine how to proceed based on the
> input the Director provides at that time.
> - Sam Ruby,
> on behalf of the HTML WG co-chairs
> [1] https://www.w3.org/Bugs/Public/show_bug.cgi?id=25581
> [2] http://www.w3.org/TR/html5/links.html#concept-rel-extensions
> [3] http://www.w3.org/2013/12/byte-stream-format-registry/
> [4] http://rawgit.com/silviapfeiffer/HTMLSourcingInbandTracks/
> master/index.html
Received on Friday, 6 June 2014 23:41:07 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:33:03 UTC