16:02:00 RRSAgent has joined #tt 16:02:04 logging to https://www.w3.org/2025/01/16-tt-irc 16:02:04 RRSAgent, make logs Public 16:02:05 Meeting: Timed Text Working Group Teleconference 16:02:39 Present: Andreas, Pierre, Atsushi, Gary, Nigel 16:02:43 Regrets: Chris_Needham 16:02:47 Chair: Gary, Nigel 16:02:50 scribe: nigel 16:03:19 atai has joined #tt 16:03:25 Topic: This meeting 16:04:15 Nigel: Happy New Year everyone, welcome back, hope you had a good break from this. 16:04:22 .. Today, we have on the agenda: 16:04:26 .. * DAPT 16:04:32 .. * IMSC 1.3 16:04:37 .. * Charter 2025 16:04:46 .. * AOB: "Dubtitles" 16:05:00 .. Is there anything else anyone wants to cover or make sure we get to? 16:05:12 Pierre: I have an IMSC topic to cover early please 16:05:14 pal has joined #tt 16:05:15 Nigel: Sure 16:05:36 Present+ Cyril 16:06:01 Topic: IMSC 1.3 16:06:41 Subtopic: [WR/ARIB] Character Sets w3c/imsc#544 16:06:49 Pierre: [shares screen] 16:07:02 .. ARIB kindly provides a set of characters for use in Japanese 16:07:23 .. One of them is from ARIB STD-B62 16:07:39 github: https://github.com/w3c/imsc/issues/544 16:08:02 Pierre: It's Table 5-2 16:08:11 .. Additional symbols and characters part 1 16:08:33 .. This table with UCS values - they're all Unicode characters I think 16:08:43 Nigel: Yes they're Unicode code points. 16:09:03 Pierre: Does Table 5-2 correspond with section 5.5? 16:09:30 Atsushi: No, even section 5.2 includes additional symbols in tables 5-2 and 5-3 16:09:49 .. I may have written somewhere: originally ARIB's definition is based on JIS character set. 16:10:08 .. So-called ARIB Gaiji was defined to include characters in tables 5-2 and 5-3 that are not in JIS. 16:10:43 .. But at some point the ARIB definition switched from JIS encoding system to XXX 16:11:08 ... The last bullet in 5.2 contains characters that were later included in Unicode but were "ARIB gaiji" before 16:11:22 Pierre: So Table 5-2 has nothing to do with section 5.5? 16:11:22 Atsushi: Nothing 16:11:56 Pierre: So from the liaison, everything is in Unicode except the last bullet which is from Table 5-2. 16:12:26 Atsushi: It could be possible that there was some correction to the submission from ARIB but I would not know. 16:12:38 Pierre: I will reference Table 5-2 explicitly, thank you. 16:12:55 SUMMARY: Reference Table 5-2 explicitly 16:13:37 Subtopic: Refactor the HRM w3c/imsc#586 16:13:43 github: https://github.com/w3c/imsc/pull/586 16:14:22 Pierre: The current version of IMSC includes both the definition of the profile and also the HRM 16:14:28 .. that constrains the complexity of IMSC documents. 16:14:39 .. A conformant IMSC document is defined as one that also conforms to the HRM. 16:14:58 .. Now the HRM is a separate document, and I think we had discussed in the past 16:15:09 .. removing the requirement that an IMSC document conforms to the HRM 16:15:24 .. and merely point to it as an additional specification that users might want to use. 16:15:30 .. That has two advantages, 16:15:42 .. a. It reduces the strong dependence between the specs 16:15:56 .. b. it matches reality where not every IMSC application checks the HRM 16:16:11 .. The goal is to remove the HRM from IMSC 1.3 and the suggestion is to also remove conformance 16:16:19 .. as part of the definition of a conformant IMSC document. 16:17:00 Nigel: I wanted to surface this because I wanted a wider group to have visibility, than just me and Pierre. 16:17:20 .. Also, there are other options: 16:17:26 .. 1. Keep the hard requirement 16:17:41 .. 2. Keep the hard requirement but flag that it is likely to be softened in the future 16:17:46 .. 3. Change to a SHOULD 16:17:51 .. 4. Change to a MAY 16:17:56 q+ 16:18:32 Pierre: I would not use the term MAY in practice 16:18:35 ack atsushi 16:18:37 ack ata 16:18:51 Andreas: As a data point, when we defined EBU-TT-D and discussed in HbbTV, and wanted to 16:19:04 .. align with IMSC we had long discussions about the HRM and whether we include the constraint. 16:19:15 .. We decided not to have this requirement for the HRM. 16:19:31 .. If it is a strict requirement that leaves the possibility to have EBU-TT-D documents that do not 16:19:45 .. conform to IMSC I don't think it is a big issue at the moment but it is likely to reflect the reality 16:19:48 .. as Pierre is proposing. 16:20:16 Nigel: So you're in favour of removing the requirement and referencing as an option (i.e. 4) 16:20:22 Andreas: Yes 16:20:45 Nigel: Any other thoughts? 16:21:22 Pierre: I would have a different opinion if I thought this would go against practice, so there's very little risk here. 16:21:56 SUMMARY: Remove the hard dependency on IMSC-HRM conformance, and reference as an option for users. 16:22:54 Subtopic: Update namespace documents w3c/imsc#589 16:23:02 github: https://github.com/w3c/imsc/pull/589 16:23:13 Atsushi: Sorry I haven't had time to get to this yet 16:23:20 .. I am not sure what the process is for updating namespace documents 16:23:23 .. I will consult the team 16:23:55 .. The document is on github so we can do it with a pull request 16:24:02 .. but the question is what content is required 16:24:23 Nigel: Would it be something different from what's in the pull request? 16:24:32 Atsushi: No idea actually 16:24:45 Nigel: OK, I suggest put a comment on the pull request when you know 16:25:07 Atsushi: The process says this is part of CRS publication, but we haven't done it for previous IMSC 16:25:16 .. publications so I definitely need to do something for this. 16:25:38 SUMMARY: Reviews to continue 16:26:19 Subtopic: Publication 16:26:30 Nigel: Presumably when we merge pull requests something will get published? 16:26:39 Pierre: I don't know. I do have to change the README too. 16:27:37 Nigel: I think we need the short code reserved and then presumably echidna needs to be configured. 16:27:49 .. I can't remember if we go all the way back to WD or straight to CR. 16:28:19 .. There's some bureaucracy to figure out there! 16:28:33 .. Let's take that offline. 16:29:51 [Pierre drops off the call] 16:30:03 Topic: DAPT 16:30:18 Nigel: I think we are just waiting for CR publication. 16:30:30 .. Atsushi, are we waiting for anything? 16:30:45 Atsushi: I pinged Simone for review around year end and will do again shortly. 16:31:05 .. In any case 2 months has elapsed since the first request so I will talk with plh soon. 16:31:25 Nigel: So that one HR request is the only thing holding us back? 16:31:41 Atsushi: i18n is finished, so yes, only waiting for Security on the Security considerations section. 16:32:14 Nigel: It's frustrating, can we just go ahead? When will you be able to discuss with plh? 16:32:29 Atsushi: Next Monday or Tuesday. I'm also frustrated! 16:32:34 .. I'm not sure if there is anything I can do. 16:33:04 Cyril: A question about the security review. Why do we need another review when nothing has changed security-wise? 16:33:28 Atsushi: The W3C Team got a new security lead and activity formally started late last year. 16:34:32 Cyril: OK, we may not have had formal security review but we had a long discussion with the security team, 16:34:36 .. that should be mentioned, right? 16:34:44 Atsushi: That was with the Privacy group? 16:35:06 Nigel: We put a fingerprint icon on, for sure 16:35:12 Atsushi: That should be privacy 16:35:26 Cyril: It's a profile of TTML2 so the security review of TTML2 applies to the profile. 16:36:00 Nigel: We do introduce new features that aren't in TTML2. 16:36:12 Cyril: Should we write down a quick paragraph to help them scope the review quickly? 16:36:16 Nigel: Not a bad idea 16:36:40 Cyril: I'll draft that 16:36:41 Nigel: Thank you 16:37:19 Cyril: Assuming we go to CR at some point, then we have to work on the implementation report. 16:37:26 .. Nigel you did work on that already. What needs to be done? 16:37:37 .. Do we need work, or just to get implementations to report what they do? 16:37:53 Nigel: Yes, we need to add the recently added features, if I didn't already do that. 16:38:14 .. Also most importantly we need to create a test suite for the DAPT features not in TTML2. 16:38:50 .. Then we can add into the implementation report the tests so that we can demonstrate 16:38:55 .. the tests that each implementation passes or fails. 16:39:22 .. Then that tells the story of how we have met the CR exit requirements 16:39:27 s/requirements/criteria 16:39:49 Cyril: Thinking of at-risk features, they're not new, because they're in TTML2, so they 16:40:02 .. won't be part of the implementation report, so how will we resolve those issues? 16:40:14 Nigel: Interesting question. 16:40:22 atai has joined #tt 16:40:34 Cyril: Implementation feedback, of course, but we will make a decision based on implementer feedback? 16:40:37 Nigel: Yes I think so 16:40:48 Cyril: We should encourage people to provide feedback on this 16:41:17 Nigel: I propose we add into the implementation report each at risk feature as a row, 16:41:36 .. and then show which implementations implement each feature so we can make a clearer decision, 16:41:53 .. even though there's no formal requirement for DAPT-specific tests with them. 16:42:19 Cyril: I think it's a good idea/ 16:42:28 s|a/|a 16:42:56 Cyril: Hard to tell now, but what is your expectation in terms of timeline? 16:43:05 .. Can we publish Rec in 2025. 16:43:08 Nigel: I expect so, yes. 16:44:17 .. Not sure if I mentioned it yet, but the EBU Eurovox project has already implemented a DAPT output. 16:44:52 Topic: Charter 2025 16:45:23 Nigel: Not much to say except that there has been a notification of the new charter work, 16:45:32 .. based on what we did at the end of last year. Thank you Atsushi. 16:45:40 Atsushi: We are now at HR stage. 16:45:58 .. Advanced notice was sent to AC Reps, external parties like public-new-work mailing list of W3C. 16:46:11 .. HR should finish within 2 months and we will go to AC review right after that. 16:46:40 .. Our changes are not large in terms of text, I don't expect to get large amounts of comment from the HR 16:46:42 .. groups or AC. 16:46:57 Nigel: In other words, we can forget about this for a while! 16:47:02 Atsushi: Yeah 16:47:19 Nigel: The only thing is there are some TODOs on it, for example when we've published IMSC 1.3 16:47:30 .. in some form then we need to update the links to it. 16:47:49 Atsushi: For that point, to publish FPWD the spec needs to be in the Charter, 16:47:58 .. so I think we should publish the ED for that. 16:48:13 Nigel: I don't agree, I think it is already in scope of the current charter to produce new versions 16:48:16 .. of existing Recs. 16:48:29 Atsushi: Could be part of Profile of TTML 16:48:39 Nigel: No doubt, it definitely is! 16:49:07 .. If the next stage is FPWD then that's what I'd like us to do. 16:49:22 .. Anything else on Charter? 16:49:32 nothing else for now 16:49:51 Nigel: I will remove this from the ongoing agenda unless you want to raise it again, or something comes up. 16:50:04 Topic: AOB - Dubtitles 16:50:31 Gary: Background: "Dubtitles" are what people have been calling subtitles that use the dubbing script 16:50:52 .. for the text. Normally translation subtitles have a different timing match to the original audio. 16:50:59 .. With dubtitles the timing matches the dubbing audio. 16:51:14 .. For viewers, sometimes there's a lot of mismatch so it can be a frustrating experience. 16:51:31 .. You might hear something in the original audio but then the translation cue comes up later or earlier. 16:51:49 .. My question is: is there something we can do technology-wise to help reduce the use of dubtitles. 16:52:03 .. One of the issues is likely the cost, where if you only generate one thing then it's cheaper than 16:52:19 .. generating a subtitle that matches the original audio and then a separate one that matches the dubbing script. 16:52:43 .. I don't know if there's something in DASH or HLS or somewhere down the stack that's missing that makes 16:52:56 .. it less likely that people will create both subtitle tracks. 16:53:08 Cyril: I'm not sure I understand why you want to reduce the use of dubtitles? 16:53:26 Gary: If I'm watching in the original audio then I want subtitles that match the timing of the audio. 16:53:36 Cyril: "captions" in the US 16:53:41 Gary: Yes. But what's happening is that the timing matches the dubbed audio. 16:53:44 Cyril: In what language? 16:54:03 Gary: This comes up a lot in anime, where if I try to watch in the Japanese original audio but the captions 16:54:13 q+ 16:54:14 .. are the English dubbed audio captions. 16:54:36 Cyril: The problem is the subtitles for English are created from the dub instead of the transcribed Japanese? 16:54:55 Gary: Yes, the main issue is the timing of when the cues are shown, which are derived from the dubbed audio. 16:55:09 .. If you're watching in the original Japanese the translation cues don't show up when you're expecting 16:55:14 .. based on the Japanese audio. 16:55:23 .. The specific content of the subtitles is less of an important issue. 16:55:32 .. The dubbing translation is usually good enough. 16:55:50 Cyril: That's related to DAPT, where the use case was to avoid discrepancies between the dubbed audio 16:55:58 .. and the translated subtitles in the same language. 16:56:30 Gary: I think it's related, but yes there's weird discrepancies. 16:56:31 ack at 16:56:46 Andreas: From my understanding this needs a linkage between the audio language and the 16:56:55 .. translated subtitles, and I don't think that exists. 16:57:12 .. You can watch the same video image with any of the audio or subtitle languages offered. 16:57:16 .. Right now there's no solution. 16:57:28 .. You could of course use those dubtitles with the dubbed version, which should fit. 16:57:36 Gary: That should be fine because the timing should align in that case. 16:57:54 Cyril: It's also a constraint you can put in the workflows, not to create dubs with timing that is too different 16:57:56 .. to the original. 16:58:11 Gary: It's more complicated because in the dub sometimes there are extra lines spoken where there's no 16:58:24 .. dialogue in the original. Then you see extra subtitles when nobody is speaking. 16:58:39 Cyril: Sounds like an annotation to show that an event is not in the original language. 16:59:01 .. In DAPT you would have... er, not sure how we support that. 16:59:16 Nigel: I've got beads of sweat worrying about if we support this! 16:59:30 Cyril: It's like audio description, describing something not being spoken. 16:59:38 Gary: They are spoken, just only in the dubbed audio. 16:59:48 Cyril: It's an interesting use case. Can we work on a concrete example? 16:59:58 .. I would be interested to see content that demonstrates this. 17:00:58 q+ 17:01:09 .. Annotating extra subtitles could be done, and the player could act on that. 17:01:11 ack at 17:01:34 Andreas: Would a simple solution be to distribute the metadata about the source language, 17:01:53 .. so if you combine it with some other audio track then there could be problems. 17:02:11 .. It's not just a timing problem, but also about the content, because subtitles from the dubbed version 17:02:25 .. used for the original do not match. That's another possible issue. 17:02:40 Gary: Yes, if you know the original language and watch the subtitles in that language it's an issue. 17:02:59 .. For the anime example it's not an issue for me, Japanese audio and English subtitles, 17:03:21 .. but for dubtitles when the timing matches up it's not an issue. 17:03:34 .. When the timing is so different then it makes it hard to watch. 17:03:50 .. I agree maybe the issue is, in downstream like DASH and HLS, we need a way to associate specific 17:03:57 .. subtitle tracks with specific audio tracks. 17:04:07 .. With DAPT it could be useful if there are these annotations already. 17:04:47 Nigel: I feel that in DAPT we have enough metadata to add the annotations but it needs checking. 17:04:51 Topic: Meeting close 17:05:00 .. Let's adjourn a little over time today, thanks everyone. 17:05:03 .. Next call in 2 weeks. 17:05:18 .. [adjourns meeting] 17:06:06 rrsagent, make minutes 17:06:07 I have made the request to generate https://www.w3.org/2025/01/16-tt-minutes.html nigel 17:15:41 scribeOptions: -final -noEmbedDiagnostics 17:15:44 zakim, end meeting 17:15:44 As of this point the attendees have been Andreas, Pierre, Atsushi, Gary, Nigel, Cyril 17:15:46 RRSAgent, please draft minutes v2 17:15:47 I have made the request to generate https://www.w3.org/2025/01/16-tt-minutes.html Zakim 17:15:53 I am happy to have been of service, nigel; please remember to excuse RRSAgent. Goodbye 17:15:54 Zakim has left #tt 17:27:54 rrsagent, excuse us 17:27:54 I see no action items