W3C

Timed Text Working Group Teleconference

13 Sep 2018

See also: IRC log

Attendees

Present
Andreas, Cyril, Glenn, Pierre, Nigel, Thierry
Regrets
None
Chair
Nigel
Scribe
nigel

Contents


<scribe> scribe: nigel

Cyril: I can stay only for an hour today

This meeting

Nigel: Today we have CfC Status update, Implementation Report run-through on each of
... TTML1 3rd Edition, TTML2 and IMSC 1.1, and any other open agenda issues.
... There's one I know of which is for audio features on TTML2.
... Then we can also cover IMSC vNext Requirements and I'm not aware of anything else.
... Any other points to cover, or other business?

Glenn: When we get to TTML2 I'd like to get approval for a pull request that's outstanding.

Nigel: Okay let's look at that in the TTML2 agenda item.
... By the way I haven't put TPAC agenda on the meeting agenda yet, we need to begin
... thinking more about that in the coming weeks.
... By the way there is a wiki page for TPAC so please add your names if you have not already,
... and if you intend to attend.

TPAC 2018 TTWG page

CfC status update

Nigel: As per the plan we agreed I issued CfCs for TTML1 3rd Edition, TTML2 and IMSC 1.1
... yesterday, which began the review period.
... Please do check the documents are suitable for publication as PR. We won't request the
... transition to PR until we have completed the Implementation Reports.

Glenn: Please could you remind us of what date we have to submit the transition request by?

TTML specs timeline

Nigel: Yes, we are on the "TTML2" column for timing for all three specs now.
... That means end of CfC 26th September, IR complete 27th September, Staff checks
... and uploads specs to final destination on TR on 28th September, and PR transition request
... submitted on 28th September.
... One thing to note about the CfCs is the SoTD sections have been updated for PR,
... and need to be checked.
... Thierry, please could you check the AC review link is the right one?

Thierry: Yes, I'll check that.

Nigel: Thanks. Another thing is for TTML2 there may be a feature removal/adjustment to
... be made, and there seems to be one other pull request to review.
... On the whole though, we're in a pretty good state, the state we said we'd be in!
... Thank you everyone for your hard work getting us to here.
... A few more leaps to make of course!
... Any comments on those CfCs?

group: [silence]

TTML1 Implementation Report

TTML1 3rd Edition Implementation Report

Nigel: I see it is partially populated at the moment, with entries for imscJS and empty
... columns for TTPE and ttval.

Glenn: Please could we review the CR exit criteria?

Nigel: Two independent implementations

Glenn: So if I add TTV or TTX in would that be adequate?

Nigel: Yes

Pierre: One column or two separate ones?

Glenn: Separate ones. We can leave the TTPE one in place and mark the two value font
... size tests as passed. I may have a chance to verify the other ones and will attempt to
... do so on the TTPE column.
... I will run all the tests through TTX and TTV to make sure everything is kosher there, shortly.

Pierre: Just to confirm, in the case of the anamorphic font tests, there will be one
... presentation engine implementation and there will be one or more validator implementations.

Glenn: Pierre, will you be filling in the ttval column?

Pierre: I will do for at least the two value font size tests.

Nigel: I'm a little uncertain still after getting a response to my advance notice to the Director
... about our approach to demonstrating implementations of those features. The reason
... for my uncertainty at this stage is because the spec changes did not affect validation
... but only affected computation of the font size.
... So a mere validation test could arguably offer no demonstration of implementability of
... the change since TTML1 2ed.
... The Director seems to want something that does show that. It could be that a validator
... is okay, but certainly not a simple XSD schema runner.

Pierre: The exit criteria is clear - just 2 implementations, without qualifying what kind of
... implementations. I'm trying to understand what were the exact concerns of the Director.
... Moving the goalposts at this point is unreasonable.

Glenn: Before we dive into this, I don't think we're depending on what the Director is
... worried about. We have a pass on presentation in TTPE for those two tests and I think
... the ttval column will be ticked. Neither ttval or TTPE make use of schema only validators
... anyway so that concern is not applicable.

group: [discussion of the minimum requirements for demonstrating that each test has
... passed]

Pierre: Note that changes to TTML1 text are not in the test suite for TTML2, because we
... will not test them twice.

Glenn: Yes, the TTML1 text changes are matched in TTML2, deliberately.

Nigel: As set out above we effectively have 14 days from today to complete the implementation
... report. Is there any reason we would not be able to do that?

group: [no reason to say no]

TTML1 Issues and Pull Requests

Nigel: There are no issues or pull requests marked for the agenda.
... Just want to call out that pull request #367 is for the PR version. I knocked it together
... yesterday to be able to get the CfC out while America was asleep. So please do review
... the changes made there and the SoTD in particular.

Pierre: Looks good, I'm just merging in the CR exit criteria tests. Thanks for doing that.

Nigel: No problem.

TTML2 Implementation Report

<glenn> https://docs.google.com/spreadsheets/d/1gtUAV0r4Zd1NUSEcFclBqOrk41pOyaOTfaLxc7boBeQ/edit#gid=0

TTML2 Implementation Report wiki page

Nigel: I see Glenn just posted the Google spreadsheet that we're using as a work in progress
... Thanks for that.
... The #T column colour code shows if we are passing or failing on CR exit criteria.
... There are a few of those.

Glenn: The one that have yellow in the TTPE column, I'll be taking the yellow out and those
... will all be turning into normal Xs so that will cause those items to be green on the #T
... column, which is my final flag for passing the exit criteria at this point.
... I've started updating the total numbers and the numbers on the right side because there
... have been some changes in the IRT Subcheck column and the NFLX-V column where
... previously an X was reported and now it is an S which is described in the readme file
... of the repository.
... S means "strictly passes", i.e. does not produce any false negative on validity tests.
... F means "fully passes", i.e. S but also does not fail to report any invalidity on the invalidity tests,
... so there are no false positive tests on the invalidity.
... I am counting only those marked F and discounting S as equivalent to "partial" at this
... point. I don't think there will be an issue from doing this. I need to update the totals
... to make sure they reflect the change to S on some of those entries.
... The reason I'm fairly confident that there's not going to be an issue there is that TTV
... reports F on all entries and ttval reports F on most except for a few like audio features,
... luminanceGain and disparity.
... That basically leaves unresolved in my mind the issue you posted Nigel on the audio
... features and whether or not we are going to be able to check all those off.
... There were a few that you feel may need to come out because you can't report a
... positive implementation on those, right?

Nigel: Yes, here's an update on the audio features.
... First, I've just opened a pull request, just before this meeting, adding a set of audio tests
... including all the audio styling attributes and applying them to p, span, audio and animate
... elements, so that should assist with demonstrating those features, especially if they
... pass validation.
... If anyone can test them for validity that would be helpful.

Glenn: I will run those through the validator. I might need to add a Wave format validator.

Nigel: We don't need to validate the WAV file format.

Glenn: Unfortunately the way TTV works I may need to add a simple validator to check
... that a WAV file is ok.

Nigel: Thank you.
... The next part of the update is regarding implementation itself.
... I have good news in the sense that I've managed to steer the oil tanker of the BBC to
... apply some development effort to completing this, which should be complete by Sep 21
... which is within the timescales we have to work in.

Cyril: Quick update on TTML1 3rd Ed - we have an implementation that passes the two
... value font size presentation test.

group: [general happiness]

Nigel: Back to the audio feature implementation.
... I expect our implementation to pass on pan, gain, speak and pitch.
... I haven't created an embedded audio test, but if time allows we will try to implement it.
... We will try to implement #embedded-audio.

Pierre: Should we prepare a pull request that removes those features in case we don't
... pass the CR exit criteria for those features?

Glenn: I can prepare a pull request but would rather wait until 22nd to do that.

Nigel: Yes, we should have finished by the 21st.

Pierre: Works for me.

Nigel: We need to get any pull requests merged during the CfC period, so we should aim
... to merge such a pull request before the end of the CfC period.
... Also I want to point out that in general we want specs to be stable during CfC but in
... this case, anticipating the potential change, I flagged it as a possibility in the CfC.
... I would like to remove #embedded-audio, #gain and #pan from #audio-speech
... regardless of what happens because they are not required to support text to speech.

Glenn: I agree because the others can be mixed in.

Nigel: Additional motivation for doing this is that they cannot all be implemented on the
... same individual content element right now.

Audio related feature changes ttml2#990

github: https://github.com/w3c/ttml2/issues/990

Nigel: Summarising discussion before we hit this agenda topic,
... Glenn to prepare pull request removing #embedded-audio, #gain and #pan from #audio-speech
... I'd like to change #embedded-audio to #audio in #audio-description.

Glenn: I'm happy to do that, especially if it's a barrier to getting the spec out the door.

Nigel: I think it probably will be.

Glenn: That leaves the question if there will be a demonstration of #embedded-audio
... If you do implement #embedded-audio should we leave them in #audio-speech?

Nigel: No, still remove them please.

Glenn: I'm okay with that.
... That's changing the #audio-description and #audio-speech feature.

Nigel: I propose we leave #embedded-audio in for the time being and I will signal as soon
... as I know if we will be able to do it.

Glenn: You also proposed removing #speech which I argued against.
... I prefer to leave it in. I know you suggested signalling it indirectly through #speak
... which is possible but I don't like the indirection.

Nigel: I think it's more direct.

Glenn: There's a corner case for transformation processing, does #speak imply that a
... text to speech processor is required for a transformation processor?

Nigel: I would scope the requirement for a speech processor to presentation semantics of #speak.
... Put it this way, we don't have a processor feature for a font rasteriser, but any presentation
... processor needs one, for visual presentation of text.

Glenn: That's true, but that feels like a comment for a CR change rather than a change to
... make now. If this feature does no harm we should leave it in.

Nigel: That's acceptable, but not ideal.
... Should we open a pull request now making the changes we've agreed to, and then
... another to make any other changes needed?

Glenn: Yes I would prefer to do that.

RESOLUTION: @skynavga to change #embedded-audio to #audio in #audio-description
... @skynavga to remove #embedded-audio, #gain and #pan from #audio-speech

Glenn: Note the text in 9.3.1 that connects the output of a speech synthesis processor
... to the web audio input.

SUMMARY: If #embedded-audio is unlikely to be implemented, consider removing later; Nigel to inform the group if this is going to be the case by 21st September.

Change to PR status. ttml2#999

github: https://github.com/w3c/ttml2/pull/999

Glenn: I fixed the pubrules issue so please re-review.

Nigel: Note that this (build) branch is the one the CfC points at.

Glenn: I'd prefer to merge it.

Nigel: Merging it means the ED gives the impression that we have moved to PR already.

Pierre: It's an editorial decision. Something else to consider is that for substantive changes
... merge them into master and then merge that back into the proposed rec branch, so
... the ED is always synced and the PR branch has the substantive text.

Glenn: I understand but have not done that practice so far and do not with to change.
... It's not a bad idea.
... The only intent with this pull request is to get to PR, not to bless the branch as a review
... branch. Since it's already out I can't change that now.
... People looking at the ED might get confused.

Nigel: I'm concerned with confusion also, in case someone outside the WG thinks the spec
... has already been transitioned to PR when they look at the ED.
... This doesn't really matter, we've done it both ways for different specs.

IMSC 1.1 Implementation Report

IMSC 1.1 Implementation Report

Nigel: At the moment all additional features that were not in IMSC 1.0.1 but which are in
... IMSC 1.1 are also introduced as new features into TTML2, right?

Pierre: Yes

Nigel: Therefore as noted in the IR there are no additional tests.
... And if we meet the CR Exit Criteria for TTML2 then we also meet them for IMSC 1.1.

IMSC 1.1 Issues and Pull Requests

Nigel: We have two open pull requests, one being the PR prep branch pull request,
... and the other being a tidy-up opened an hour ago.
... Does that tidy-up address all the open issues?

Pierre: Yes, and Nigel's private email to me about line breaks, purely editorial.

Nigel: Thank you.
... That was about words being moved from one line to another without any change in text.

Pierre: If you could review that pull request as early as possible that would be great - it will
... clean up the PR branch.

Nigel: Thank you, I'll certainly take a look - happy for others too also, of course.
... Anything else on IMSC 1.1?

Pierre: One thing, more an FYI than a fatal issue. There are two tests that will be used on
... the TTML2 IR that are not in the TTML2 test repo, for disparity and luminanceGain.

Glenn: That's not true. If there are tests in IMSC intended to be used by TTML2 I'm not aware
... of them. I have tests for both disparity and luminanceGain in the TTML2 test suite at
... this point. Those are the official ones at this point as far as I'm concerned.
... A number of the tests in the TTML2 tests repository are derived from tests that were in
... the IMSC 1.1 test suite and I've marked those in the XML comments.

Pierre: There are no TTML2 tests for luminanceGain and disparity in ttml2-tests now. I
... just searched.

Glenn: [looks for them]

Nigel: I found 10 results searching for luminanceGain.

Pierre: There are no presentation tests.

Glenn: That's correct. We should put some in there just like Nigel submitted for audio,
... if you would like to add them to the presentation tests then we can put them in there.

Pierre: I sent them in an email to you.

Glenn: I will look for those.

Pierre: Unless they are broken please don't change them and use them as is.

Glenn: I may remove the IMSC profile.

Pierre: Yes, that's fine.
... Can we approve the IMSC 1.1 tests pull request?

IMSC 1.1 tests imsc-tests#67

github: https://github.com/w3c/imsc-tests/pull/67

Nigel: What's the scope of these?

Pierre: They are intended to cover TTML2 features that are present in IMSC 1.1 that were
... not present in IMSC 1.0.1. They are not intended to be CR exit criteria tests, but tests
... to assist implementers. There are source files and PNG renders, following exactly the
... same pattern as the IMSC 1 tests.

Nigel: Sounds good to me.
... I've approved them so they can be merged.
... Thanks for those.
... This is a really good resource.

Pierre: It's to help implementers check their implementations are behaving correctly.

IMSC vNext Requirements

Nigel: We said we would publish after resolving the open issues.
... Let's look at the status...
... We have no open pull requests and the only open issue is marked for IMSCvNext, i.e.
... later than IMSC 1.1.
... So we can now publish as a WG Note.
... Thierry, what do we have to do to publish as a Note?

Thierry: Just let me know and I can publish it.

Nigel: Okay, we have a resolution, it's completed, please could you publish it as a Note?

Thierry: OK, yes, sure.

Nigel: Thank you!

Meeting Close

Nigel: We've covered everything on our agenda, so thank you everyone, meet same time
... next week. [adjourns meeting]

Summary of Action Items

Summary of Resolutions

  1. @skynavga to change #embedded-audio to #audio in #audio-description
[End of minutes]

Minutes formatted by David Booth's scribe.perl version 1.152 (CVS log)
$Date: 2018/09/13 16:44:20 $