EPUB 3 Working Group Telco — Minutes

Date: 2020-12-11

See also the Agenda and the IRC Log


Present: Zheng Xu (徐征), Matthew Chan, Wendy Reid, Masakazu Kitahara, Toshiaki Koike, Ben Schroeter, Shinya Takami (高見真也), Marisa DeMeglio, Brady Duga, Garth Conboy, Yutaka Suzuki

Regrets: Jun’Ichi Yoshii, Daihei Shiohama (塩濱大平), Nellie McKesson, Ivan Herman

Guests: Dave Cramer

Chair: Wendy Reid

Scribe(s): Matthew Chan


Matthew Chan: Topic 1: Multiple Renditions.

See github issue #1436.

See github pull request #1438.

Wendy Reid: this is continuing the discussion from last week.
… the suggestion is to remove references to multiple renditions from the main document of the spec.

Dave Cramer: the possibility of multiple renditions has always been in epub.
… but has not achieve a lot of uptake.
… i’m not aware of any major RS that supports it.
… with those references in the spec, the precision of the language required becomes cumbersome.
… it also gives casual readers of the spec the impression that multiple renditions is more prevalent than it is.
… Matt G’s idea is to have those references to multiple rendition moved from where they currently are (scattered throughout the spec) into a satellite document.
… Matt G has already started this process of editorializing the spec.
… the satellite would be a WG note, and not a Rec track document.

Garth Conboy: there is at least one RS that supports it, so it makes sense to still keep multiple rendition functionality in the spec.
… that’s why I am in favor of Matt G’s direction.

Shinya Takami (高見真也): multiple renditions are currently used in Japan, mostly for educational purposes.
… but I agree with moving the multiple rendition specific portion of the spec to a separate document as long as this means that multiple renditions are not deprecated.

Dave Cramer: Readium also had some support for multiple renditions.
… at the time Microsoft was working on epub support in Edge.
… as part of that process, they found some oddball things in the spec that they found confusing.
… if another browser were to ask for advice on supporting epub today, I would recommend that they not support multiple renditions.

Marisa DeMeglio: wish we could go back to 2008 and reverse the decision to support multiple renditions.
… support is kind of mess right now.

Brady Duga: the first thing that we tell you about epub in the spec is something about multiple renditions, I can see how that is confusing.

Garth Conboy: +1.

Proposed resolution: Remove mentions of multiple renditions from the core and reading systems documents, close issue #1436 and merge PR #1438. (Wendy Reid)

Shinya Takami (高見真也): +1.

Marisa DeMeglio: +2.

Toshiaki Koike: +1.

Garth Conboy: +1.

Brady Duga: +1.

Masakazu Kitahara: +1.

Resolution #1: Remove mentions of multiple renditions from the core and reading systems documents, close issue #1436 and merge PR #1438.

Wendy Reid: to keep all the documents together, Ivan has proposed that we publish the multiple renditions piece as a note.

Dave Cramer: here is a link to the old IDPF version.

Dave Cramer: See Old IDPF Version of the multiple rendition spec.

Proposed resolution: Publish Multiple Renditions as a Working Group Note. (Wendy Reid)

Garth Conboy: +1.

Matthew Chan: +1.

Wendy Reid: +1.

Marisa DeMeglio: +1.

Brady Duga: +1.

Ben Schroeter: +1.

Shinya Takami (高見真也): +1.

Masakazu Kitahara: +1.

Resolution #2: Publish Multiple Renditions as a Working Group Note.

Wendy Reid: one of the other documents we have to publish is the overview note that ties everything together.

Wendy Reid: See Draft Overview.

Proposed resolution: Publish Overview as a Working Group Note. (Wendy Reid)

Wendy Reid: +1.

Brady Duga: +1.

Toshiaki Koike: +1.

Shinya Takami (高見真也): +1.

Wendy Reid: this is the overview document that is the introduction to the spec.

Masakazu Kitahara: +1.

Matthew Chan: +1.

Garth Conboy: +1.

Resolution #3: Publish Overview as a Working Group Note.

1. External Content and iFrames

See github issue #1061..

Wendy Reid: the use case that brought this up was linking YouTube videos (or similar content) in textbooks.

Dave Cramer: this is a complicated issue because it pulls us in 2 different directions.
… one of the strengths of epub is that it is self-contained.
… we’ve allowed this before with external fonts.
… BUT this use case is reasonably compelling too so….

Marisa DeMeglio: Has anyone given much thought to the relationship between fallbacks and external content?.
… if you fallback to an image or transcript, or something like that that is easy to bundle, is that allowed?.
… Matt G clarifies the distinction between foreign and external resources in the issue.
… which is on point.

Dave Cramer: one reason that we put this on the agenda was to get a sense of whether this use case is important in the Asian market.
… has this limit frustrated Asian content authors.

Garth Conboy: how far along are we to allowing video content without fallbacks? Are we already there?.

Wendy Reid: in practice, i’ve seen video elements with external urls as href.

Brady Duga: it feels like this is worse, because video and audio are limited in what you can do with them.
… you could just make an epub shell that references your real book that exists in a totally separate website.

Dave Cramer: yeah, it’s a slippery slope.

Wendy Reid: i’m pretty sure that in the wild i’ve seen youtube videos in ebooks (not that they work well/at all depending on the RS).
… but what possible way do we have to distinguish a link to a video vs a completely different website.

Brady Duga: we’d like to think that epubs are essentially web content, but there are lots of ways in which RS and browsers are different (e.g. security).

Ben Schroeter: i think the fact that we’ve already seen this in the wild pushes me to err in favor of wider adoption, but also mitigate it in some way.
… i.e. not recommend it.
… but disallowing it entirely is problematic.

Brady Duga: I’m not seeing youtube in ebooks.

Dave Cramer: https://github.com/w3c/epubcheck/issues/852.

Wendy Reid: the place i think it might happen more often is where size limitation come into play.
… maybe its full of interviews or for whatever reason its full of videos.
… if we wanted to cut the size from GBs back to MBs, one way is to link out to the videos.

Ben Schroeter: I do see how it is a slippery slope, we should try to make that slope less slippery.

Dave Cramer: there are a lot of moving pieces here… maybe some of us should revisit the issues in more detail, get the problem in better focus.

Brady Duga: I’m thinking about the security implications of this, and we aren’t ready for this.
… I don’t think many RS devs have consider external content as an attack vector.
… we should talk to HTML people to understand what the risks are here.
… the functionality of playing an externally hosted video in your epub already exists, but we need to better understand the risks of doing so.

Wendy Reid: one of the things we should start thinking about is horizontal review.
… one of those topics for review will be security and privacy.

Dave Cramer: it sounds like we’re not ready to resolve on this right now.

Wendy Reid: agree.

Dave Cramer: so we take it back to github for now.

Wendy Reid: might be worth taking this to the business group? Asking e.g. if there is a need to make special provision for video in addition to what we already have..
… next week will be our last meeting of 2020.
… no meeting on week of 21st or 28th.
… january 7th will be first meeting of 2021, at this same time (7 eastern).

Dave Cramer: RRSAgent: draft minutes.

Dave Cramer: RRSAgent: bye.

2. Resolutions