Resolve open issues for TTML2 2e.

[andreastai]

TTML2 has 73 open issues. 24 of them are substantive changes. It may be helpful to pick out the issues that need more discussion and which are not automatically candidate for this years release.

[nigelmegitt]

+1 to https://github.com/w3c/tt-reqs/issues/1#issuecomment-457577789 please @skynavga and thanks for checking that @tairt !

[skynavga]

I am presently assuming we will attempt to address all of these issues in TTML2 2e. However, in case we cannot do so, we have various options, such as push to TTML2 3e or TTML3.

[skynavga]

Move issues that clearly target new features into new TTML3 repository.

[css-meeting-bot]

The Timed Text Working Group just discussed Resolve open issues in ttml2 repository. tt-reqs#1, and agreed to the following:

• SUMMARY: TTML3 issues to move to new repo, this issue to cover TTML2 2nd Ed changes only, @skynavga to triage issues.

The full IRC log of that discussion

<nigel> Topic: Resolve open issues in ttml2 repository. tt-reqs#1
<nigel> github: https://github.com/w3c/tt-reqs/issues/1
<nigel> Nigel: Is there any more detail we can add to this now?
<nigel> Glenn: No, not that I know of, unless we want to go through the 73 issues.
<nigel> .. I need to start processing them right away.
<nigel> .. Quite a few of them are small, some were pushed forward that may not be so small that I need to
<nigel> .. start on.
<nigel> Andreas: Do we take it as a given that we solve them all?
<nigel> Glenn: As many as possible. If we have favourite ones then ping me.
<nigel> Pierre: Timetable?
<nigel> Glenn: June 1 for FPWD of 2nd Ed.
<nigel> Pierre: One meta-issue is setting limits on values.
<nigel> Glenn: Implementation limits?
<nigel> Pierre: Maximum number limits like on seconds.
<nigel> Glenn: We have some in the spec already, from TTML1 1st Ed.
<nigel> .. We haven't really pushed specifying limits. I think feature definitions would be the best place.
<nigel> .. For example something that says how many colors are supported.
<nigel> Pierre: Right, a specific example is number of seconds.
<nigel> Glenn: We haven't said anything about that.
<nigel> Pierre: 32-bit or 64-bit. That's a ton of work, so we need to decide on that.
<nigel> Andreas: Does it cause problems?
<nigel> Pierre: It has caused problems, because someone had used media time origin as 1970 and that blew
<nigel> .. up an implementation which didn't allocate enough bits to the number of seconds.
<nigel> Nigel: We do that sometimes!
<nigel> Pierre: It turned into a more complex problem than at first it appeared.
<nigel> Glenn: We don't have an issue on this, do we?
<nigel> Pierre: Maybe on TTML1. It could be a feature designator for minimal support, say.
<nigel> Nigel: Sounds like a good idea to me.
<nigel> Glenn: We couldn't retro-actively apply it to TTML1. The ship has sailed.
<nigel> .. They would be in the range of a semantic restriction of an existing feature.
<nigel> Pierre: We can introduce new features.
<nigel> Nigel: Yes we can.
<nigel> .. Take it further - if a processor feature says 32-bit number of seconds then does that invalidate content
<nigel> .. with time expressions that could go beyond 32-bit numbers?
<nigel> Pierre: We began to touch on this in the TTML1 issue.
<nigel> Glenn: Say we define a limits feature and define a 32-bit one. Absent such a feature in the processor
<nigel> .. profile it would effectively be undefined.
<nigel> .. Then in a content profile I don't know what it means.
<nigel> -> https://github.com/w3c/ttml2/issues/1023 Constrain maximum value of @length on data element. ttml2#1023
<nigel> -> https://github.com/w3c/ttml1/issues/307 Least upper bound on supported time expression values. ttml1#307
<nigel> Pierre: what's the view on this?
<nigel> Nigel: I want to know more about the implementer pain levels
<nigel> Pierre: We know at least about time expressions causing pain.
<nigel> Andreas: I would support doing it for time expressions
<nigel> Nigel: We can ask others of course. For example I can imagine DVB implementers wanting to know this
<nigel> .. detali.
<nigel> Nigel: Coming back to the macro requirement, are all the substantive issues for 2nd Ed?
<nigel> Glenn: We haven't created a TTML3 repo yet.
<nigel> Pierre: There are a couple tagged for TTML.next and 2nd Ed milestone but don't belong in 2nd Ed.
<nigel> Glenn: Can we get a new repo for TTML3?
<nigel> Nigel: Yes I don't see why not if that's how you want to do it.
<nigel> -> https://github.com/w3c/ttwg/issues/23 Create TTML3 repos ttwg#23
<nigel> Nigel: I've assigned that to Thierry
<nigel> Glenn: I need to triage these. Most of the ttml.next ones need to get pushed to TTML3.
<nigel> Pierre: Can you do this now so we can go over them this afternoon. It would be awesome if we can go
<nigel> s/go/get
<nigel> .. get a good idea of it today.
<nigel> Glenn: I didn't come prepared for that.
<nigel> Andreas: If nobody has missed a feature and filed it then it may not be a candidate for TTML3
<nigel> Glenn: I don't understand
<nigel> Andreas: We opened requirements up and if nobody raised requirements for missing features then you
<nigel> .. could argue they are not in scope.
<nigel> Pierre: We can't leave "resolve all issues in TTML2" open today
<nigel> Glenn: That was a catch-all requirement.
<nigel> Andreas: I agree with Pierre we need to go through them today. 10 substantive features coming in would
<nigel> .. change the whole picture.
<nigel> Pierre: Can you make a first pass?
<tmichel> https://github.com/w3c/ttml3-tests and https://github.com/w3c/ttml3 created
<nigel> Glenn: I can't do a first pass today, I can go through it this evening and change ttml.next
<nigel> .. to ttml3 where it's my first approximation and the group can confirm it tomorrow.
<nigel> .. If I think there are things for 2nd ed then I'll mark that too. It'll take me a couple of hours.
<nigel> Pierre: The most important is to change the milestone.
<nigel> Glenn: Once we have the TTML3 repo I need to transfer them to that repo.
<nigel> Pierre: You can transfer issues on GitHub if you're an owner
<nigel> Thierry: oka
<nigel> s/oka/okay
<nigel> Glenn: I promise not to make any other changes under the covers!
<nigel> Nigel: Summarising, it is clear which specs are being targeted. We don't have consensus yet on which
<nigel> .. things to adopt, pending a more detailed review.
<nigel> Nigel: For the substantive changes I want to get an idea of what the test will look like.
<nigel> Glenn: In a preliminary basis we can describe at a high level the kind of things we need to see tested.
<nigel> .. For example HDR images would require images with HDR coding in them. That's a high level test.
<tmichel> ttml2 and ttml3 repos : added Glenn and Nigel as Admin.
<nigel> Pierre: Can we change this specifically to TTML2 2nd Ed and constrain it to editorial features?
<nigel> Glenn: We could add a ttml3 tag and include moving new features to ttml3.
<nigel> Pierre: Just this one requirement.
<nigel> Andreas: It makes sense to fix bugs in 2nd Ed, we don't need a big discussion.
<nigel> .. All new features are new requirements so I expect them not to be in TTML3. If there are important
<nigel> .. ones then they need to be submitted, but that period is over.
<nigel> Pierre: I totally agree.
<nigel> group: [discussion of handling this requirement issue]
<nigel> Glenn: I will change the issue title to Resolve open issues to TTML2 2nd Ed.
<nigel> Pierre: thank you
<nigel> SUMMARY: TTML3 issues to move to new repo, this issue to cover TTML2 2nd Ed changes only, @skynavga to triage issues.

[nigelmegitt]

Issues were triaged, no further changes expected in TTML2. Closing.