13:59:13 RRSAgent has joined #tt 13:59:13 logging to http://www.w3.org/2017/05/18-tt-irc 13:59:15 RRSAgent, make logs public 13:59:15 Zakim has joined #tt 13:59:17 Zakim, this will be TTML 13:59:17 ok, trackbot 13:59:18 Meeting: Timed Text Working Group Teleconference 13:59:18 Date: 18 May 2017 13:59:31 Present: Pierre, Dae, Glenn, Nigel 13:59:47 Regrets: Andreas, Mike 13:59:50 Chair: Nigel 13:59:52 scribe: nigel 14:02:36 Topic: This meeting 14:03:19 Regrets+ Thierry 14:03:50 Nigel: For today, we have 2 hours. I don't think there's anything to discuss re TPAC, so 14:04:00 glenn has joined #tt 14:04:30 .. I think we'll be focusing on TTML1 progress, issues, pull requests etc. Do we need time 14:04:31 .. on IMSC? 14:04:39 Pierre: Yes, should be very quick but there's a blocker there. 14:05:16 Nigel: I think the HDR in PNG note has had its time, and I haven't had any responses, so 14:05:22 .. let's discuss publishing that as a Note. 14:06:02 .. Any other business or particular points to raise? 14:06:16 Pierre: Dae didn't you propose resolutions on a bunch of issues? 14:06:25 Dae: Yes but they're waiting for feedback from Richard Ishida. 14:06:46 Nigel: I don't have any other business, but just noting today is Global Accessibility Awareness Day. 14:06:50 Topic: IMSC 14:07:03 Pierre: There's a pull request: 14:07:34 -> https://github.com/w3c/imsc/pull/230 Added explicit spaces in tts:aspectRatio and tts:activeArea definitions (issue #221) 14:07:50 -> https://github.com/w3c/imsc/issues/221 Attribute syntax definition: missing spaces 14:08:06 Pierre: In TTML1 there's prose that has not been imported into IMSC1 about spaces being 14:08:27 .. required between non-terminal tokens. It was never in IMSC1 even though it followed 14:08:47 .. the conventions. So here I propose a pull request that explicitly adds a single space 14:09:23 .. between the tokens in ittp:activeArea and ittp:activeArea. However Glenn is not happy 14:09:26 .. with that. 14:09:52 Glenn: I think many readers would assume that the TTML1 rules already apply even though 14:10:11 .. it is not explicitly stated. By introducing a space there we are going against how 14:10:26 .. attribute syntax is specified in TTML1 and TTML2 since it does not do that except to 14:10:41 .. call it out when those rules do not apply. Also the way it is quoted as a double quoted 14:10:53 .. white space is ambiguous because we cannot tell which character it is. Also it does not 14:11:07 .. work in all contexts even with XML since it is possible to escape white space and it may 14:11:19 .. not be normalised. So the way the comment has been resolved is inconsistent and it is 14:11:33 .. much easier if you simply refer to the TTML1 rule in the convention section or something 14:11:35 .. like that. 14:12:28 Pierre: Nigel, what's your take on that? 14:12:50 Nigel: This is new to me, however for the reason that implementers should not need to 14:13:12 .. create a special attribute parser just for these two attributes, I would agree with Glenn. 14:14:34 Pierre: Okay I'll do that. I'll need to copy the text in otherwise I would have to reference the 14:14:46 .. two places in TTML1 where this is defined, one for parameter attributes and the other for 14:15:10 .. style attributes? Oh actually both are parameters. Thanks, I'll go ahead. 14:15:31 Nigel: There are two other pull requests for IMSC - do we need to discuss those? 14:15:39 Pierre: We can do that offline, no need to discuss today. 14:16:02 Pierre: Also FYI there are two issues Nigel that need your review, and everyone in the Group's, 14:16:07 .. for CR exit criteria. 14:16:27 Glenn: Question: Pierre, how did you resolve that issue about the white space and the 14:16:32 .. fontFamily expression? 14:16:43 Pierre: That's still under discussion, there's no pull request on that. It's on the IMSC test 14:16:49 .. suite not on IMSC1. 14:17:04 Glenn: Your point was based on a presumption about TTML1 that may or may not be true. 14:17:27 -> https://github.com/w3c/imsc-tests/issues/7 FontFamily009.ttml has a spurious space 14:17:50 Pierre: That has an impact on TTML1 and TTML2. 14:18:06 Glenn: The issue is whether or not space is permitted around terms in a comma separated 14:18:19 .. list, and even more generally whether space is permitted around other delimiters, of which 14:18:33 .. we have a variety. That generic language we were talking about for an implied whitespace 14:18:46 .. between two non-terminals: if you have another kind of delimiter there then that language 14:19:02 .. does not read on the question of if it is permissible to have white space between the delimiter 14:19:25 .. and the term that follows. In this particular issue someone had read it as indicating that 14:19:37 .. white space is not allowed in that context but if you look at the original CSS2 grammar 14:19:52 .. specification from 1998 and this spec you'll find examples where white space appears 14:20:06 .. around terms in a delimiter separated list, and the same in XSL-FO. We did not call this 14:20:19 .. out in TTML but there's a good case for saying that white space is permitted. 14:20:47 .. This will affect all the TTML-based languages. 14:21:27 Pierre: I've arrived at a different implementation from Glenn here. 14:21:44 Nigel: Do we have example data points here? I would expect to see "comma space font name" 14:21:53 .. in real world examples, and I'm sure I've seen that. 14:22:04 Glenn: I think the original DFXP implementations and TTV does permit it. 14:23:03 Pierre: It would be helpful and relevant to see example content here. RGBA values with 14:23:10 .. white spaces are more complex to process. 14:24:38 Glenn: I don't think the spec argues this clearly either way. 14:24:51 Pierre: There are no IMSC tests except for the fontFamily one that demonstrate this. 14:25:01 Glenn: There are some older tests for DFXP that I can go back and look at. 14:25:14 Pierre: At least 2 people in the world read it in a particular way, so it would be a 14:25:25 .. disservice to go back and change TTML1 to make implementations incompatible unless 14:25:33 .. we can show that many documents exist that have that issue. 14:27:34 Nigel: There's an example at http://bbc.github.io/subtitle-guidelines/#tts-fontFamily that shows comma separated lists. 14:28:18 .. I just provide this in the spirit of a single data point. Look at the second row in the 14:28:26 .. document requirements section. 14:29:01 Pierre: We may extend this to fonts but I'm not comfortable extending it across the board. 14:29:13 .. This is about not making existing implementations stop working just by a stroke of the 14:29:15 .. pen on the spec. 14:29:25 pal has joined #tt 14:29:27 Nigel: I would go back to my previous point that it should be possible to have a single 14:29:44 .. attribute value tokeniser algorithm rather than being required to use different ones. 14:29:56 Glenn: I don't think we can resolve this but I'd point out that the new conventions that just 14:30:22 .. went into TTML2 explicitly allow for white space around commas and semicolons where 14:30:36 .. they are delimited. That would extend to all argument lists that use commas for example. 14:30:48 Pierre: Unless there's a really compelling reason to do that I'm not sure why we'd need to 14:31:01 .. broaden the scope there and increase the number of test cases. Also we would need to 14:31:14 .. be careful about terminal and non-terminal values, what about time expressions? 14:31:29 Glenn: No, that's explicitly dealt with; white space is prohibited from those time expressions. 14:31:42 Pierre: Not in TTML1. Unless there's a really good reason, regardless of CSS, we should 14:31:49 .. remove flexibility rather than increase it. 14:32:03 Glenn: For implementers that assume that whitespace is permitted, and authors who 14:32:18 .. assume it is permitted then your position might make their assumption invalid. 14:32:30 Pierre: Only for authors. If we are going to make that change, we need to know if authors 14:32:36 .. have been using that capability. 14:32:44 Glenn: So we need more input on this. 14:32:49 Nigel: I agree we cannot resolve it today. 14:33:45 .. Specifically we would want to know if there are implementations that do not work properly 14:34:00 .. in the case that spaces exist, and if there are documents that include additional spaces. 14:34:51 Topic: TTML issue assignment and progress tracking 14:35:22 Nigel: Looking at the milestones, we have 36 open, 47 closed on the Editor's list for WR, 14:35:27 .. which is 56% complete. 14:35:39 .. And we have 5 open 0 closed on the Group's WR action required list. 14:36:17 Glenn: Approximately 22 have been closed in the last week. If I can keep up this rate then 14:36:28 .. we are going to be pretty close to getting to 100% by the end of this month, so that is 14:36:30 .. my hope. 14:37:53 Glenn: I noticed that Glenn has offered to work on #20 and has offered a pull request, 14:38:06 .. thank you for that. I'm working on an update to that pull request today. Can I assign 14:38:09 .. that to you Pierre? 14:38:22 -> https://github.com/w3c/ttml2/issues/30 How to specify aspect ratio to understand positioning that may apply for display or video 14:39:03 Glenn: This Pull Request will not be merged instantly. 14:39:11 Pierre: I don't think 3 days would be adequate for this one. 14:39:44 Glenn: [assigns issue to Pierre and Glenn] We're both working on this right now. 14:40:20 Nigel: What's next on everyone's slate for issues to pick up? 14:40:30 Glenn: I'm actively working on a number that I am working on. I cleared a number of the 14:40:45 .. assignments to myself so that others could feel free to work on them. Since then I have 14:40:49 .. picked up a few of them. 14:41:19 .. In one case I submitted a pull request that was assigned to you Nigel. 14:41:24 Nigel: I noticed that! 14:41:39 Glenn: Dae, I have a follow-on request on one of the Ruby examples that I'd like to ask you 14:41:49 .. to fine tune so I will coordinate with you on the side on that. 14:42:12 -> https://github.com/w3c/ttml2/issues/203 Add examples of new features commonly used with Japanese content (2 of 2) 14:42:25 Glenn: Also I'd like to point out that there are number of places in the spec where examples 14:42:39 .. are needed, so Dae if you have a chance and some time we would certainly welcome 14:42:44 .. more submissions on those. 14:43:00 Dae: I'll give the document another pass-through and see what I can pick up. 14:43:59 Nigel: There's been activity on #128. 14:44:11 -> https://github.com/w3c/ttml2/issues/128 The uniqueness of xml:id needs to be broken for some uses of condition 14:44:20 Glenn: I'll try to add some data points to that today. 14:45:07 Glenn: I'd appreciate it if you could pick up #224 and #156 Nigel. 14:45:18 Nigel: Okay I'll look at those and see if I can take them on. 14:45:32 Glenn: Also #135 clarify timing concepts in relation to SMIL. 14:46:47 Nigel: We did do some of that already, and there's a note on the issue for Pierre to add 14:46:55 .. something about container diagrams. 14:47:34 Glenn: At one point there was an ask to more formally define the times than in SMIL. 14:47:46 Nigel: We did the work already in the wiki, perhaps it just needs to be validated and formatted 14:47:48 .. into a pull request. 14:47:54 Glenn: My worry is it will be difficult to validate. 14:48:21 Nigel: In that case I would propose a WG Note explaining how we interpret SMIL in the context 14:48:23 .. of TTML. 14:48:36 Glenn: I think that's a good idea, and could be added to the spec later. We need to do it in 14:48:47 .. a quasi informative manner that can be validated rather than making it normative spec 14:48:54 .. text that may unknowingly break things. 14:49:05 .. I think all of us have done some implementation work on this and came up with different 14:49:14 .. implementations... 14:49:18 Nigel: That's a worrying sign. 14:49:31 Glenn: The amount of test content in relation to timing is pretty minimal. 14:51:07 Nigel: I have a lot of cases that can be generated from the EBU-TT Live Interoperability Toolkit's 14:52:00 .. BDD tests. That can be done for the TTML2 test suite though they are subject to some 14:52:20 .. starting constraints such as parallel only time container semantics, and dur only permitted 14:52:33 .. on body, but they would generate a large number of test documents and expected 14:52:36 .. processing outcomes. 14:52:53 Glenn: I will also need your help on #96 the extension to add date support to time expressions. 14:53:12 .. I need to read the comments that came in from Nigel and Addison. I'm reticent to putting 14:53:19 .. back in time zone support but I am open to persuasion. 14:53:56 Nigel: Okay. I will review that and see if I can add a further comment. 14:55:27 Nigel: Any further points on issues? 14:55:40 Dae: I will be taking a look, and need to prompt Richard Ishida on some of the open issues. 14:57:34 Dae: How long should we give the commenter to respond, if we're hitting the end of June? 14:57:44 .. Would 7 days be reasonable? 14:58:02 Nigel: From the Process perspective we can take a view on each issue and we only have 14:58:22 .. to dispose of all the wide review comments for transition to CR, so we could reassess 14:58:27 .. the state say in the middle of June. 14:58:43 Pierre: I have a slightly different view - if we take weeks to respond to a comment and then 14:58:56 .. give a short 7 day deadline that might seem funny. 15:02:55 -> https://github.com/w3c/ttml2/issues/265 No mention of isolation for directional controls 15:03:04 Nigel: This is assigned to you Pierre, and the last comment is from Richard. 15:03:30 Pierre: This is a new feature of CSS with low levels of support; unless what we have today 15:03:39 .. really does not work my view is to defer the feature to TTML.next. 15:03:45 To add to scribe below "Pierre: I have a slightly different view - if we take weeks to respond to a comment and then give a short 7 day deadline that might seem funny" 15:04:10 "Dae: This is specifically about issues where the commenter and I are actively going back and forth and one side stops replying" 15:05:09 Glenn: This has already entered the Unicode bidi algorithm. 15:05:18 Pierre: I'm not the best person to comment on this. 15:05:32 Glenn: Also Unicode added explicit control characters with the isolate semantics, not in 15:05:45 .. the bidi spec. The original reason for the bidi properties in CSS were to provide a stylesheet 15:05:58 .. mechanism that would express the same information as was in the explicit bidi control 15:06:10 .. characters that would allow authors to avoid using those characters. Given the current 15:06:20 .. state since it is permitted in the character content that's a case where you could not 15:06:35 .. represent it in style information in TTML right now whereas in CSS you can. I was going 15:06:47 .. to suggest that we accept this change and add the necessary properties. 15:06:54 Pierre: I would not object to that. 15:07:04 Glenn: I do agree it would be work for implementations and testing. 15:07:19 Pierre: imsc.js would support it to the extent that browsers support it, which is spotty. 15:07:29 Glenn: The community will demand it so it will come along. 15:07:38 Pierre: Hopefully we'll have better support when we get to PR. 15:07:48 Glenn: I'm adding a comment to say that I generally support this. 15:07:54 Pierre: I can generate a pull request for it then. 15:07:57 Glenn: Sounds good to me. 15:10:53 Nigel: We need to have at least a placeholder for an example there too. 15:11:45 Topic: TTML1 & TTML2 issues, action, PRs, editorial actions etc 15:18:09 Pierre: People interested in aspect ratios etc should look at the pull request I drafted yesterday: 15:18:18 -> https://github.com/w3c/ttml2/pull/321 Initial pass at rationalizing aspect ratio and pixel dimensions 15:18:31 Glenn: As I mentioned before I am in the process of creating a new commit for this branch 15:18:38 .. which will generate some further discussion. 15:18:57 .. This will knock off at least 2 or maybe 3 related issues which I think I've already 15:19:03 .. incorporated into #30 by reference at this point. 15:21:41 Nigel: Regarding mediaOffset Glenn and I had some email discussion. 15:21:55 Glenn: I need to read your message carefully on that so it's pending. We are not 15:22:06 .. synchronised in our understanding at this point. I don't have anything specific that I 15:22:09 .. need input on right now. 15:23:50 -> https://github.com/w3c/ttml2/issues/96 Specify date as well as hours, minutes and seconds in time expressions 15:24:25 Nigel: In this case I think we need the option of a timezone because there are two possible 15:24:44 .. valid use cases for clockMode="local", one in which just whatever local timezone applies 15:25:32 .. is used, so the timezone is not specified, and the other is that a specific timezone is 15:25:41 .. intended and needs to be specified. 15:25:47 Pierre: How would you encode the timezone? 15:31:04 Glenn: Using the same syntax as in the source for this, which is SMIL, and the timezone part is based on ISO 8601. 15:38:12 group: Discussion of the merits and ambiguity/clarity of including a timezone component 15:38:32 .. in local times - Nigel argues in favour on the basis of operational utility, understanding 15:38:49 .. that a local time with a timezone offset is a different way to express a UTC time; 15:39:03 .. Glenn and Pierre argue that if a UTC time is intended then a UTC time should be used 15:39:11 .. and that local times always need to be treated locally. 15:42:12 Nigel: In that case if we are going to use local in this way we need to clarify it. 15:42:16 Glenn: That seems reasonable. 15:42:21 Nigel: I've added a comment on the issue. 15:43:16 -> https://github.com/w3c/ttml2/issues/125 Add ttm:mediaTimestamp (or equivalent) attribute 15:43:21 Glenn: I need to review your input Nigel. 15:44:27 .. I also need to understand the proposal to use set in #128 15:44:34 -> https://github.com/w3c/ttml2/issues/128 The uniqueness of xml:id needs to be broken for some uses of condition 15:44:47 Pierre: I also need to consider the impact on implementations there. The bigger question 15:45:00 .. of when condition is evaluated was brought up, which is somewhat orthogonal but 15:45:13 .. something we need to consider at some point. It impacts more than just this issue. 15:45:41 Nigel: I agree - this was one of my earliest questions regarding the condition mechanism. 15:46:26 Glenn: My current position is that it needs to be resolved at presentation time. Also there 15:46:36 .. is a special case that can be made that some of the semantics of a style element should 15:46:51 .. not be ignored even though it is conditionally excluded. Because of chained referential 15:47:05 .. styling you might have two or three styles that refer back to something that gets incorporated. 15:47:17 .. If you conditionally exclude a style in the middle of a chain does that break the chain 15:47:33 .. or just exclude those style attributes defined by that style element? 15:47:50 .. This is a case where partial semantics need to be retained. I've implemented that in TTXV. 15:48:49 Nigel: This points to a problem possibly with the use of the term "ignore" in that it does 15:49:01 .. not mean that the element itself is ignored but that the things it defines are ignored. 15:49:49 Glenn: Yes that is exactly the case. 15:50:45 Nigel: So in terms of action we need to change the term ignore or define it better. 15:50:52 Glenn: I agree that more clarification is needed. 15:50:59 Pierre: It has to be added to the style resolution process. 15:51:01 Glenn: I agree. 15:52:28 .. I have some tests in the TTT test suite that test this. And condition is a feature so it ca 15:52:38 s/ And condition is a feature so it ca/ 15:52:50 Topic: HDR in PNG 15:53:00 action-495? 15:53:00 action-495 -- Thierry Michel to Update the ttwg homepage and publications pages for the new repos -- due 2017-04-20 -- OPEN 15:53:00 http://www.w3.org/AudioVideo/TT/tracker/actions/495 15:53:50 Nigel: I see that this is done. 15:54:07 close action-495 15:54:07 Closed action-495. 15:56:49 PROPOSAL: Publish the PQ HDR in PNG document as a Working Group Note 15:57:11 Nigel: I've just spotted that the ICC file claims that it has copyright with Adobe Systems. 15:57:38 Glenn: Apache licensing doesn't allow use of an ICC file; we had to make other arrangements. 15:57:49 .. It was copyright by Adobe. 15:58:00 Pierre: So Adobe holds a copyright on every ICC file ever made? 15:58:12 Glenn: No, there's a standard one that's widely used in the industry but Apache decided 15:58:18 .. we could not include that in any Apache project. 15:58:27 Pierre: This ICC file is bespoke and was made by hand. 15:59:14 .. Thanks for highlighting this. It was not taken from any existing tool. 15:59:26 Nigel: Presumably we need to update the copyright notice here to say W3C. 16:00:06 Pierre: I will follow up with whoever created it. 16:04:12 Zakim has left #tt 16:04:40 Nigel: I think we can resolve to publish that after making those changes. 16:04:53 Pierre: Okay, if I learn that we cannot change the copyright notice on the ICC I will notify 16:04:55 .. the group. 16:05:28 RESOLUTION: After applying fixes to the outstanding issues, publish the PQ HDR in PNG document as a WG Note. 16:06:05 Nigel: Thanks everyone. [adjourns meeting] 16:06:12 rrsagent, make minutes 16:06:12 I have made the request to generate http://www.w3.org/2017/05/18-tt-minutes.html nigel 16:14:35 i|-> https://github.com/w3c/ttml2/issues/265|Dae: This is specifically about issues where the commenter and I are actively going back and forth and one side stops replying 16:14:41 rrsagent, make minutes 16:14:41 I have made the request to generate http://www.w3.org/2017/05/18-tt-minutes.html nigel 16:14:59 s| To add to scribe below "Pierre: I have a slightly different view - if we take weeks to respond to a comment and then give a short 7 day deadline that might seem funny"| 16:15:08 s|"Dae: This is specifically about issues where the commenter and I are actively going back and forth and one side stops replying"| 16:15:29 rrsagent, make minutes 16:15:29 I have made the request to generate http://www.w3.org/2017/05/18-tt-minutes.html nigel 16:17:40 ScribeOptions: -final -noEmbedDiagnostics 16:17:42 rrsagent, make minutes 16:17:42 I have made the request to generate http://www.w3.org/2017/05/18-tt-minutes.html nigel