W3C

Media Sub-Group, HTML-A11Y Task Force

17 Nov 2010

See also: IRC log

Attendees

Present
Janina, John_Foliot, Geoff_Freed, silvia, Sean_Hayes, Judy, Kenny_Johar, Plh
Regrets
Chair
John_Foliot
Scribe
janina

Contents


<JF> the call is restricted at this time?

Hi, Everyone: REMINDER Zakim Code today is 26631#

<JF> aha

John, use today';s zakim code

<scribe> scribe: janina

<scribe> agenda: this

Identify Scribe

If she can last, Janina will attempt to do the honors today ...

Actions Review http://www.w3.org/WAI/PF/HTML/track/actions/open

<Sean> conference code?

<Sean> the code is not letting me in. says restricted at this time

Sean, you need to use 26631#

It's our special zakim code for today only -- 26631#

<JF> zakim who is here

<JF> http://www.w3.org/WAI/PF/HTML/track/actions/67

re action 67 on to file bugs we will close action 67

<silvia> close action-67

<trackbot> ACTION-67 And Silvia (and perhaps Eric) to file bugs to tweak language in Editors draft closed

re action 68 on jf --

<JF> http://www.w3.org/WAI/PF/HTML/track/actions/68

leave open

re action 69 on silvia -

<JF> http://www.w3.org/WAI/PF/HTML/track/actions/69

<scribe> done

<silvia> http://www.w3.org/WAI/PF/HTML/wiki/TextFormat_Mapping_to_Requirements

<silvia> close action-69

<trackbot> ACTION-69 Work up checklist table for WebSRT closed

<JF> http://www.w3.org/WAI/PF/HTML/track/actions/76

<silvia> close action-76

<trackbot> ACTION-76 Replace the technology column in our matrix with Frank's categorizations closed

leave action-76 open for now

OK, we'll close it!

<JF> http://www.w3.org/WAI/PF/HTML/track/actions/88

Biggest issue is how to get data from client to server

Silvia is part of the Wg

This action was cloned from PF which was interested in general.

PF cloned it because it seemed particularly appropriate to Media in HTML

We'll leave it open for now.

Candidate Formats Review: WebSRT; TTML

<Sean> http://sn1-pptbroadcast.officeapps.live.com/PowerPointBroadcast.aspx?pptbid=c399ec9a-0ac9-40f5-a4b0-ee98aa0460d7

This is Sean's web slide presentation ...

Designed to support multiple formats, smil compatible

Can construct own profile in xml

Supports custom timing

Requires a default lang, but inline lang also supported

Can define custom profile, or use one of the provided standard profiles

Hierarchy: div, p, span ...

Netflicks captioning in DFXP

It's one level -- cannot div inside a div

Style defining authoring intent

Allows grouping of inline styles, so that locating captions doesn't become overly verbose

If wanted css, would apply over that

CSS styling would work--it's just external to TTML itself

User styling overide would use an external style sheet

JF: Could we create a profile that disallowed internal ttml styling?

Sean: Yes, will address shortly

Style can reference a previous style block

zakim drop me

Would a browser that implements ttml need to implement ttml styling, or at least a mapping to css

Most maps to css2, some only to css3

Silvia: So mapping is required?

Sean: Yes, will discuss shortly

<JF> JF wonders about browser extensions (common in emergent CSS3)

TTML pub date is tomorrow -- Thursday, 18 November

BBC is using for English and Welsh captions

Several iptv players, some ed sites, and free conversion tools supporting ttml

Geoff: NCAM has player -- Adobe flash uses ttml

Silvia: How much content uses more than just basic ml?

Sean: several authoring tools that are quite complete
... From what appears on line, more than the basics

jf: the jw player also supports ttml profile

Silvia: which?

jf: same as adobe?

Silvia: which does adobe support?

jf: xml like

<silvia> basic profile

Sean: Next slide, Moby Dick slide, added DC metadata, and showing structured nav points
... Shows a straight forward extension of ttml, not implemented anywhere yet
... Pretty straight forward mapping for IE9 and Firefox, a bit more problematic for Safari

<silvia> Sean: http://www.mirovideoconverter.com/ <- ogg encoder

jf: could one create a block for caption text that enlarged text?

Sean: Yes, mapping at each time segment

Kenny, we're at zakim code 26631 today only

<kenny_j> thanks janina. will join in a sec

<JF> http://www.3playmedia.com/

Discussion on locating caption text -- over video or alongside?

Sean: My ttml profile supports anywhere

Geoff: There are other applications of TTML in the works, and I believe it's use is much wider than Sean showed.
... Uptick because it's a W3C recommendation (tomorrow)

Silvia now presenting on WebSRT

<silvia> http://blog.gingertech.net/wp-content/uploads/2010/11/WebSRT/#slide1

<Sean> can someone remind me of the code

<JF> 26631

SRT was attractive to me because it's so trivial to parse.

Mozilla's current official position is that ttml not compatible with how Mozilla wants to handle captions

I want to leave that aside, though, and look at this from our requirements perspective

WebSRT has been developed specifically for html5, expanding on SRT

Intent is that people can post their SRT files on the web, and they'll just work ...

Silvia's explaining ml in slide 3

<JF> plh: http://blog.gingertech.net/wp-content/uploads/2010/11/WebSRT/#slide3

Looking at slide 4 -- WebSRT for captions, texted video descriptions, subtitles, and kareoke

PLH: We're on zakim 26631, if you want to join

Minimal ml available for text, by intent

<plh> janina, I'm on the bridge

Great, PLH.

Slide 6 -- Showing how it comes together

Chapters there for navigation, using identifier plus start/end time

jf: asking about hierarchical navigation?

Silvia: WebSRT is still flexible, we can still fix shortcomings, don't know how open Ian is to that, though
... Hierarchical nav now only possible if we use multiple files--other workarounds

Geoff: Assuming these slides show what Ian has defined for WebSRT as of now, correct?

Silvia: Yes.
... Supports a voice ml, so can identify speaker, or a segment of music, etc
... All chars are utf8, unlike previous SRT wich code use any encoding
... Looking at use cases, video description,
... word by word timing ...

<JF> Link for Judy: http://blog.gingertech.net/wp-content/uploads/2010/11/WebSRT/#slide10

Silvia: metadata example -- html parsable

<JF> http://blog.gingertech.net/wp-content/uploads/2010/11/WebSRT/#slide10

Silvia: Jason ml would also be supported
... Jason is for archiving databases, appreciated by large sites with many many files
... Slide 12 shows ml that's currently allowed by WebSRT
... Slide 13 showing Japanese
... Showing positioning at right or left, as Asian languages are vertica
... Currently only renders text on top of video

Sean: Why not use CSS?

Silvia: Don't know. Also have this concern.
... I've heard Ian considered CSS too complex for this application
... Slide 14 showing only available markers -- vert, horizontal, etc
... Slide 15 -- If captioning audio, needs to be wrapped in video element, as video renders to screen, and audio does not

PLH, Yes, he said he would be doing that

Silvia: Next slides showing more complex rendering via css
... Summary; Lots of potential with metadata; things missing; very capable format, though
... Personal opinion is either works for me
... Mozilla and others strong aversion to xml parsing
... So prefer WebSRT for that, and other reasons

Geoff: Interested in the arguments

Silvia: Would tend to suggest all of css could be used
... sibling ml wouldn't work in live captioning, or in file where interleaved with video stream

<kenny_j> need to drop off now. Got to run to another meeting. Bye all.

Sean: So can't break into the middle of a file?

Silvia: Yes, but must first pass headers

Judy: Wonders whether subsetting ttml would provide what we need but avoid existing objections

Silvia: Objections are pretty generally against any xml format

Geoff: General comment -- Concerned that browser mfgs might be setting a11y policy in a way that isn't necessarily helpful to pwds

<JF> +1 to judy's comments

Judy: The bodies that set policy are empowered by our analysis -- starting from user requirements and continuing to what the formats do, and don't support

<Sean> my slides are at ftp://ftp.cwmwenallt.com/ username cwmdownload password Accessibility1

PHL: There's the tech discussion and the feature discussion -- Browsers may have prefs on tech direction, but features are another matter

Judy: but if we were to find some features not addressable in websrt, that would be another matter

phl: agrees

Judy: Didn't our TTML discussion reveal that we could avoid some of the less comfortable technologies that browser devs wanted to avoid?

PHL: I look at how do we move tech to meet our identified feature requirements

Judy: So, still wondering how far a subsetting could go?

Silvia: Don't think an xml format will be acceptable
... We can and should point out shortcomings and say that the format is unacceptable if these shortcomings aren't fixed

Sean: But, what's the point if we have a format that already delivers what's needed?
... If the devs have presented a fete accompli, what's the point?

PLH: Both formats could meet?

Sean: Yes, either format could meet

PHL: So, if we hand off to html, they'll probably go websrt

Sean: and we won't implement until it's a w3c req

Judy: Have we articulated interoperability concerns sufficiently?

jf: It's a problem if we say either format can do it,
... we really should focus on a definitive format
... I may be wrong, but believe we need a defined, preferred format

Sean: But we don't have all the dimensions of that

Silvia: This TF shouldn't be making the decision on what is baseline and what goes into the spec
... We can say format x is preferable because it supports these features
... Or format y has these shortcomings
... I believe it will be a useful exercise for this group to do that analyis

<Zakim> Judy, you wanted to say has my thought back

Judy: If there were one format that objectively supported a11y better, it would be incumbant on this group to make that recommendation
... Don't see that the case is yet strongly stated

PHL: So, what is the timeline?
... It seems there are currently two different discussions, one in HTML WG and one in this TF

jf: That's what we've started doing here

Geoff: My comment also on the timeline -- Now that we know TTML is a rec, and is broadly used, perhaps people will start using it while we take our time, here and in the html wg, to debate

Judy: This is why we have the mega long call today

PHL: Not meaning to criticize -- but we may miss opportunity if we don't move fast

<silvia> http://www.w3.org/WAI/PF/HTML/wiki/TextFormat_Mapping_to_Requirements

Now going through the format reqs looking for what ttml and srt currently support

<silvia> http://www.w3.org/WAI/PF/HTML/wiki/Media_Accessibility_Checklist

dv-14 ttml=yes websrt=no

Silvia: We may rely on media nnotations for copyright -- dv-=14

cn-2 ttml=yes websrt=no--not hierarchical

Silvia: Suggest doing entire cn section

Discussion that we should see examples of how it's done in ttml; suggesting maybe both need work

JS: Already solved in DAISY which is now sync'd to epub (IDPF)

Sean: Nested in ttml
... Am intending an example in ttml

<Sean> http://www.cwmwenallt.com/ttml/ttmldemo.htm

jf: how do we get an websrt example?

Silvia: I will do for WebSRT

<Sean> Only tested in IE9 and Firefox

js: We only need two implementations right?

<plh> Sean, does your page work for you right now?

<plh> it seems the server is borken. I don't even get html source code out of your link

jf: Two weeks? We'll not meet next week due to U.S. Thanksgiving holliday

Silvia: Three probably more realistic, but will try for two

Sean: Yes, have other priorities, but this one is also very important

cn-10 multiple simoultaneous text tracks -- ttml=yes websrt=?

<silvia> websrt=yes through multiple tracks

cc-2 both ok

cc-4 says char encoding, do we have lang attrib elsewhere?

cc -- where rendered?

websrt only in the viewport

A current shortcoming

ttml=yes

<silvia> cc-5 that is

cc-6 both ok

cc-7 both ok

cc-13 ttml=yes; websrt=needs info

Now believe both ok

cc-14 ttml=yes; websrt=css??

Silvia to clarify with example

cc-16/17 ttml=yes; websrt=no

<silvia> cc-15 tml=yes; websrt=yes

cc-18 ttml=yes, via namespace, -- frowned on

<silvia> websrt=yes

cc-27 more difficult in xml; but is being done

Silvia: has been raised as an issue

ecc-1 more complex in websrt

jf: important in educational settings, specifically dublin core

pp-2 ttml=yes; websrt=no

jf: seem two big differences--structural nav and text rendering; also metadata

<Sean> paper talking about XML encoding and streaming http://www.bayardo.org/ps/www04.pdf

<plh> time will be 5pm ET in two weeks

<silvia> have a great thanksgiving !

<silvia> I don't even know what thanksgiving is :P

<plh> http://en.wikipedia.org/wiki/Thanksgiving

<plh> and the day after thanksgiving : http://en.wikipedia.org/wiki/Black_Friday_%28shopping%29

<silvia> I was teasing ;)

Summary of Action Items

[End of minutes]

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$Date: 2010/11/30 17:23:43 $