RE: Open Container Format and Multiple Renditions

Garth,

Thank you.

With regard to rendition selection mechanisms, in addition to the OCF-based approach in “EPUB Multiple-Rendition Publications 1.0”, a packages-based approach could involve the utilization and comparison of packages’ metadata [1][2]. A topic, then, would be the minimal set of metadata elements to indicate for package metadata while considering scenarios such as portability, internationalization and accessibility. I observe that metadata elements exist for portability (e.g. the rendition:* elements) and internationalization (e.g. language elements) and, perhaps, some ontologies exist or could be created for accessibility, to describe packages as being varieties of accessible or providing certain accessibility features.


Best regards,
Adam

[1] https://w3c.github.io/publ-epub-revision/epub32/spec/epub-packages.html#sec-pkg-metadata
[2] https://w3c.github.io/publ-epub-revision/epub32/spec/epub-packages.html#sec-package-metadata

From: Garth Conboy<mailto:garth@google.com>
Sent: Thursday, July 26, 2018 5:31 PM
Subject: Re: Open Container Format and Multiple Renditions

Multiple renditions have not had a ton of uptake in EPUB-land.

The ability to specify more than one rendition is part of EPUB 3.2: https://w3c.github.io/publ-epub-revision/epub32/spec/epub-ocf.html

However, the rendition selection mechanism from "EPUB Multiple-Rendition Publications 1.0 (http://www.idpf.org/epub/renditions/multiple/)" is not included in EPUB 3.2, however it remains a valid auxiliary specification.

Best,
   Garth


On Thu, Jul 26, 2018 at 7:13 AM Adam Sobieski <adamsobieski@hotmail.com<mailto:adamsobieski@hotmail.com>> wrote:
EPUB 3 Community Group,

Greetings. The Educational Exercises and Activities Community Group has recently launched and is interested in the Open Container Format technology.

Quoting from the group’s wiki (https://www.w3.org/community/exercises-and-activities/wiki/Main_Page):

“Educational exercises and activities can be composed of hypertext and other multimedia files. Educational exercises and activities can also be collections of such files in ZIP containers. Both unpackaged and packaged scenarios are in scope for this group.

“ZIP containers for educational exercises and activities could utilize the Open Container Format with a new variety of package file.

“Multiple variants, or renditions, of an educational exercise or activity can be provided within a ZIP container. Reasons for so doing include portability, accessibility and internationalization. Such variants, or renditions, could be described by package files referenced in container.xml files, references differentiated via extensible XML attributes or media type parameters. Such variants, or renditions, could also be semantically interrelated in metadata, e.g. in metadata.xml files.”

That is, non-mutually-exclusive possibilities for implementing multiple variants or renditions in an OCF ZIP container appear to include:

1. Multiple renditions can be described via XML attributes on <rootfile> elements in container.xml files.
2. Multiple renditions can be described via media type parameters in the value of the media-type attribute on <rootfile> elements in container.xml files.
3. Multiple renditions can be interrelated in metadata.xml files.

With respect to approach 1, I found EPUB Multiple-Rendition Publications 1.0 (http://www.idpf.org/epub/renditions/multiple/). Is this recommendation going to be a part of EPUB 3.2 OCF?

Thank you for any information with respect to multiple variants or renditions of content for portability, accessibility and internationalization in OCF-based ZIP containers.


Best regards,
Adam Sobieski