15:00:57 RRSAgent has joined #tt 15:00:59 logging to https://www.w3.org/2021/10/14-tt-irc 15:01:00 RRSAgent, make logs Public 15:01:01 Meeting: Timed Text Working Group Teleconference 15:01:10 Present: Andreas, Nigel 15:01:37 Present+ Atsushi, Pierre 15:01:50 Agenda: https://github.com/w3c/ttwg/issues/200 15:02:04 Previous meeting: https://www.w3.org/2021/09/30-tt-minutes.html 15:03:27 Chair: Nigel 15:03:29 scribe: nigel 15:03:43 Topic: This meeting 15:04:18 atai has joined #tt 15:04:21 Nigel: Today we have IMSC HRM, Charter, a note about next week's call on Synchronisation accessibility user requirements (SAUR) 15:04:28 Present+ Cyril 15:05:05 Cyril: AOB from me: the MPEG file format meeting just finished - there's still a discussion about TTML in MP4 and I'd like to give an update. 15:05:14 Nigel: That'd be brilliant, thank you. 15:05:29 cyril has joined #tt 15:05:29 .. Any more business? 15:05:55 Pierre: FPWD of IMSC HRM - we should decide how to proceed with the open issue 15:06:02 Nigel: We'll bring that into the IMSC HRM agenda topic. 15:06:06 Pierre: Okay thanks 15:06:11 Present+ Mike 15:06:50 mike has joined #tt 15:06:54 Nigel: Any more? 15:07:01 q+ for do we have meeting link for next week? (might be from APA??) 15:07:08 [group has no more] 15:07:11 ack a 15:07:11 atsushi, you wanted to discuss do we have meeting link for next week? (might be from APA??) 15:07:24 Nigel: Thanks for asking Atsushi, no, I don't have a link yet. 15:07:24 present +mike 15:08:04 .. It'd be good to get one because we'll have a hard time joining without it! 15:08:12 Topic: IMSC HRM 15:08:32 Nigel: We have an initial draft, all the open PRs merged, and there's one open issue. 15:08:32 s/present +mike/present+ mike/ 15:08:39 Pierre: That's my understanding 15:09:01 Nigel: And you wanted to ask about the order of events in terms of the issue and publishing a FPWD? 15:09:17 Pierre: Exactly. We could try to resolve the outstanding issue before publishing an FPWD or 15:09:42 .. publish soon and then address that issue and any others. 15:10:14 Nigel: Suggestion: add an editorial note to the spec at the place where the issue lies, pointing to the issue, and publish FPWD with that 15:10:29 .. note present, to highlight to readers that there's an ongoing conversation about that part of the document. 15:10:32 Pierre: OK 15:10:38 Nigel: Make sense? 15:10:56 Pierre: I'm happy with it - think it's a good idea. 15:11:03 Nigel: Any other views? 15:12:17 Nigel: It's clear where in the document issue w3c/imsc-hrm#5 lies, so it should be easy to do. 15:12:24 Pierre: Absolutely, I'm just doing that as we speak. 15:12:59 .. I have also another question, which is about the document license. Can you remind me what the Charter says? 15:13:14 Nigel: We have the choice of either, on a per document basis. 15:13:38 .. There seems to be a popular move towards the software licence, which is I think more permissive than the document licence. 15:14:03 .. I discussed with Philippe and he agreed with my concern that others could fork specs and claim them to be authoritative, 15:14:27 .. but felt that addressing that with a licence wasn't the best tool; conversely, allowing the more permissive licence 15:14:42 .. makes it easier for the community to, e.g. reuse examples that may be parts of specifications. 15:14:58 .. So we can choose either. In the past we've used the document licence, but the current trend 15:15:07 .. is in favour of the software licence. It's our choice. 15:15:22 Pierre: Do you have a strong opinion? 15:15:25 Nigel: No I don't 15:15:38 Pierre: The default in Respec is the W3C Software and Document Licence 15:15:51 pal has joined #tt 15:16:27 Nigel: So anyone can do anything with it. 15:16:34 Pierre: If that's recommended, I don't have an objection. 15:17:32 -> https://www.w3.org/Consortium/Legal/2015/doc-license Document licence, as currently used in IMSC 15:19:04 Nigel: Quite a few big players in W3C have come out in favour of the software and document licence so I'm happy to go with that. 15:19:19 Pierre: The licence for IMSC 1.0.1 was pretty permissive anyway. 15:19:29 .. I think we should just use the Software and Document Licence. 15:19:53 PROPOSAL: For the IMSC HRM specification we will use the Software and Document Licence. 15:20:02 Nigel: Any objections? 15:20:10 .. hearing none: 15:20:17 RESOLUTION: For the IMSC HRM specification we will use the Software and Document Licence. 15:20:33 Nigel: Any other questions before we take it further? 15:22:15 Pierre: I'll create a pull request for the FPWD - please review. Then I guess we'll wait 2 weeks. 15:22:36 Nigel: There's no reason to wait for 2 weeks for the editorial changes of adding the note and changing the boilerplate to FPWD 15:22:50 Pierre: It's just to make it clear what we'll publish. I can create that PR today and then start the clock? 15:22:52 Nigel: Yes 15:23:33 Nigel: Given the moratorium, we'd be looking at actual publication on 1st or 2nd November. 15:23:39 Pierre: That's fine, let's start now then. 15:23:56 Nigel: Atsushi, anything extra we should think about? 15:24:21 Atsushi: It's the first publication so I don't think we need to squash or deal with existing issues. 15:24:29 .. The next slot is 2nd November 15:24:38 .. I'd like to file a transition request as soon as possible 15:24:51 .. And hopefully it will be handled on 22nd or 29th. I don't have anything further. 15:25:01 Nigel: That all sounds reasonable and doable. 15:25:20 Atsushi: We may be able to configure streamlined publication for each PR merged for this. 15:25:23 .. If we want. 15:25:26 Nigel: That's neat 15:25:28 Pierre: ? 15:25:48 Atsushi: Many WGs are publishing specs to /TR every time a pull request is merged to the main document. 15:25:52 .. We can do that if we want. 15:26:25 Nigel: We've never done it before but especially at WD it's quite tempting to share with the world what we've agreed as soon as we have 15:26:42 Atsushi: We just need a WG Resolution for that and after that we can publish WD to /TR any time. I suppose that makes our life easier. 15:26:55 .. We don't need to wait 2 weeks every time. 15:27:03 Nigel: We'd just have our 2 week pull request review period. 15:27:22 Atsushi: That depends on the WG working mode. Even after that we need to run CfC for publication for another 2 weeks. 15:27:27 Nigel: Oh I see 15:27:41 Atsushi: I forgot one point: we need to have a resolution to FPWD 15:27:45 Nigel: I'm coming to that 15:28:17 Atsushi: If we wait until 28th the timing is quite tight 15:28:32 Nigel: I'm planning to make the proposal now, just making sure everything else is sorted out first. 15:28:52 Atsushi: If possible, please issue CfC for publication as WG Note and streamlined publication 15:28:59 Pierre: It's on Rec track not Note 15:29:03 Nigel: Agreed, Rec track 15:29:31 Atsushi: Sorry, I forgot. It makes no difference for this publication stage. 15:29:39 .. We need to do the same things. 15:30:14 Nigel: Any views on streamlined publication before we proceed? I'm leaning to being in favour but I think there could be risks. 15:30:42 Atsushi: The trigger is merging a PR to the main branch so if we don't make any error for that we should be fine. 15:32:28 Nigel: In the past people have not been happy with the assumption that every PR has had full review before merging, on all our specs, 15:32:36 .. and requested a review opportunity before publication. 15:32:55 .. In this case, I think the document is much smaller than, say, TTML, and we're likely to see a smaller volume of change, so the same 15:33:00 .. concerns might not arise. 15:33:18 .. The choice before us is whether we're happy collectively to review each PR and if it gets merged then we're happy to publish, 15:33:28 .. or if instead we want a review gate before publication. 15:33:37 Atsushi: To be honest I don't have a strong opinion. 15:33:53 Pierre: My input is that we should try this more agile process and see how it goes. If it fails then we can go back. 15:33:56 .. That's my recommendation. 15:34:13 .. Technically, everything that's merged in the main branch should result in a specification that is valid. 15:34:36 .. I think that's a good goal anyway, and it's going to be a WD every time, so publishing the head of the main 15:34:50 .. branch as a WD every time it changes is not unreasonable if we can maintain discipline. 15:34:58 .. If we can't maintain discipline then we can revisit it. 15:35:07 Atsushi: This could be a good test case for us. 15:35:13 Pierre: Exactly. The risk here is small. 15:35:32 Nigel: That makes sense to me. Any other views from anyone who hasn't spoken so far? 15:35:35 Andreas: No, makes sense. 15:36:05 PROPOSAL: Adopt the streamlined publishing process for imsc-hrm so that every time a pull request is merged to the main branch a new WD is published automatically. 15:36:13 Nigel: Any last objections? 15:36:56 Atsushi: I will paste examples in other WGs. I configured this in another WG last month and it only triggered once over 9 specs. 15:37:15 Nigel: We can just configure it for this one spec, right? 15:37:21 Atsushi: Per repository, yes. 15:37:52 Nigel: I think the concept makes sense, any requests to see examples before going ahead with a resolution? 15:37:55 example resolution (can check cfc also) -> https://lists.w3.org/Archives/Public/public-immersive-web-wg/2021Sep/0004.html 15:37:56 [no requests] 15:38:10 RESOLUTION: Adopt the streamlined publishing process for imsc-hrm so that every time a pull request is merged to the main branch a new WD is published automatically. 15:40:22 PROPOSAL: Request transition of imsc-hrm to FPWD modulo addition of editorial note regarding issue #5. 15:40:32 Nigel: Any objections? 15:40:39 [no objections 15:40:49 s/ons/ons] 15:40:58 RESOLUTION: Request transition of imsc-hrm to FPWD modulo addition of editorial note regarding issue #5. 15:41:25 Nigel: As a reminder, all of these resolutions are subject to our decision policy and have a 2 week review period. 15:41:54 Topic: Charter 15:42:35 Nigel: We have a draft charter with the 4 Rec Track deliverables as listed in the agenda. 15:42:43 .. TTML2, ADPT, IMSC HRM and WebVTT 15:43:09 .. I don't have any update other than that. Anyone else? Questions, things to add, comments? 15:43:24 -> https://w3c.github.io/charter-timed-text/ Proposed draft charter 15:43:44 Atsushi: I don't have anything else. For discussion, we may need to start reviews very soon, like next week. 15:44:06 .. We may be able to update during the review process, but without starting the process we'll run out of current charter. 15:44:40 https://github.com/w3c/charter-timed-text/issues/66 15:45:05 .. This is the biggest remaining discussion point. 15:45:16 .. When we can have consensus on this ticket we can go to the next stage of asking reviews. 15:45:33 Nigel: Okay I'd better draft a pull request then. 15:45:52 .. I think there is consensus in the issue. 15:46:03 Atsushi: Yes we need consensus on the text. 15:46:18 Nigel: I've assigned that issue to myself. 15:46:38 Nigel: Any other questions? Anyone else? 15:46:57 Topic: Upcoming TTWG and APA joint breakout session next week about SAUR 15:47:13 Nigel: As mentioned at the top of the meeting, we don't have joining details for this meeting yet. 15:47:16 .. I will chase. 15:48:40 .. Actually maybe there are joining coordinates - you have to be registered for TPAC 2021 I think, which is free of charge I think. 15:48:54 .. Then there's a link from the wiki page linked from the email (here it is again): 15:49:07 -> https://www.w3.org/WAI/APA/wiki/Meetings/TPAC_2021#Introduction_to_Synchronization_Accessibility_User_Requirements_.28SAUR.29 wiki page 15:49:11 detailed description -> https://docs.google.com/document/d/19p6cA_TdMZ8yVQ_qBQITjfbLgeJ9KD3LK-LdlaR2ieA/edit 15:50:02 Nigel: Conclusion: we do have coordinates for joining, but it needs admin for each person to get there 15:50:20 Atsushi: You have to register at least 24 hours in advance. 15:50:35 .. Every time you go to the cvent page you have to login with the 6 digit secret code sent by email. 15:50:48 .. Please be aware of the time needed to get this before joining the zoom meeting. 15:50:55 .. I recommend not closing the cvent site tab. 15:51:37 Nigel: Thank you 15:51:46 .. I don't think we need a WG consensus view on the topic before attending, 15:52:05 .. we can go with our individual views and learn/contribute as the opportunity arises. 15:52:23 Topic: Update on TTML in MP4 15:52:40 Cyril: As you know there was a liaison contribution from MPEG to TTWG some months ago 15:52:53 .. saying that MPEG is updating the carriage of TTML in MP4 to deal with some confusing wording. 15:53:10 .. We had a back-and-forth and MPEG ended up with a document close to final draft (FDIS) stage. 15:53:24 .. One of the changes that was made at this last stage was a technical change to the mapping to ISOBMFF. 15:53:45 .. We have two timelines, a composition timeline and a presentation timeline and the difference is an "edit list" and MPEG 15:53:54 .. is going back and forth on whether edit lists apply to TTML. 15:53:59 .. Also applies to WebVTT. 15:54:13 .. If you think you're using edit lists then I'm interested and the MPEG group is interested. 15:54:36 Pierre: One request: would it be possible to get the consolidated section (not an amendment). 15:54:49 .. I've found it impossible to review the amendment. 15:54:59 Cyril: In this case the entire section is being replaced by the amendment. 15:55:07 q+ for (AOB) do we want to have branch protection in imsc-hrm repository, like other rec-track ones (e.g. ttml?) ? 15:55:15 Pierre: In this specific case it would be awesome if we could get a consolidated copy of part 30. 15:55:35 Mike: It's not an unreasonable request; someone would have to sit down and do it. ISO doesn't usually do that extra step. 15:55:43 .. In rare occasions they will produce a roll-up. 15:56:07 Pierre: This is true; I've found it error prone and inefficient in this highly technical case to review only the amendment. 15:56:17 Mike: No argument, it doesn't exist today. 15:56:29 Cyril: It's noted. If I produce an integrated edition you'll be in the list (the group). 15:57:01 .. My question to the group is if you're aware of using edit lists for TTML in MP4? 15:57:36 Nigel: Just for clarity, the edit list is the thing that's applied to a composition timeline to derive the presentation time, right? 15:57:53 Cyril: Yes. It's a tool that typically applies to video streams with B frame reordering. 15:58:14 .. But it's a generic tool where a timeline can be edited, e.g. shifting by X or removing or inserting part of the timeline. 15:58:34 .. In practice in a streaming environment like DASH/HLS/CMAF the only way it is used in a video stream is when the 15:58:49 .. composition time of the first frame is not zero, to map the first frame onto presentation time zero. 15:58:57 Andreas: Does one edit list apply to all media? 15:59:01 Cyril: No it's per track 15:59:12 Andreas: Does it make sense to apply an edit list just to subtitles? 15:59:27 Cyril: Yes because for each track the presentation timeline is mapped onto the video presentation timeline. 15:59:48 .. You might not need edit lists on subtitles or audio, but only video. 16:00:10 Andreas: Are edit lists applied in use cases where they also need to be applied to other tracks? 16:00:30 Cyril: Yes, an example is a movie with audio, video and text, and you want to cut out a section, the edit list would apply to all three 16:00:32 .. components. 16:00:43 Andreas: That's is, so it would be strange not to include it. 16:00:59 Cyril: I agree. MPEG decided to postpone progress on this question to study this further. 16:01:28 Mike: For Cyril's question, if someone is using edit lists with TTML today then that would be good to know, or if noone is using them then 16:01:31 .. that would be good too. 16:02:05 Nigel: Is another way to ask the same question: are people authoring TTML with timestamps on the composition timeline rather than 16:02:08 .. the presentation timeline? 16:02:13 Mike: No, it's Cyril's question. 16:03:04 Cyril: I don't think people think of it that way but the way Nigel asked it isn't wrong. 16:03:43 Nigel: Perhaps people don't understand the difference between the two timelines when they author the TTML. 16:04:04 Mike: In the broader group nobody had any awareness of it being done. 16:04:26 Cyril: As Andreas hinted, if you _don't_ apply edit lists to TTML then it has different treatment and isn't a "first class citizen". 16:04:39 Mike: It's valuable to understand what people are doing with it today. 16:04:54 Cyril: Agreed, hypothetical cases are interesting but practical ones are even more valuable. 16:05:10 Pierre: Not only in practical use, I'd broaden: has there ever been a recommendation use edit lists? 16:05:24 Cyril: No - unless audio or video there is no need to use edit lists to make it work. 16:05:36 .. For Video, for some time, you _had_ to use edit lists. 16:05:40 .. That was never the case for TTML. 16:05:55 Pierre: I understand. We're talking about the edts box? 16:06:04 Cyril: Yes and the elst entry in the edts container 16:06:14 Pierre: Does the CMAF spec mention it? 16:06:37 Cyril: CMAF only refers to the edts box for audio and video, for frame reordering and to remove priming samples, which are 16:06:53 .. coding specific things. The edit list is restricted to a specific scenario, not cutting parts of the stream out. 16:07:02 .. So it makes sense to omit it for timed text, because there's no need. 16:07:20 ack a 16:07:20 atsushi, you wanted to discuss (AOB) do we want to have branch protection in imsc-hrm repository, like other rec-track ones (e.g. ttml?) ? 16:07:24 Topic: AOB - branch protection in imsc-hrm 16:07:35 Atsushi: do we want branch protection in imsc-hrm repo? 16:07:37 Nigel: Yes we do 16:07:58 .. If we're doing streamlined publication we must have branch protection 16:08:02 Atsushi: Yes 16:08:27 Topic: Meeting close 16:08:59 Nigel: Thank you everyone, let's adjourn [adjourns meeting] 16:09:04 rrsagent, make minutes 16:09:04 I have made the request to generate https://www.w3.org/2021/10/14-tt-minutes.html nigel 16:40:14 s/That's is, so it would/That's it, so it would 16:44:01 s/Topic: AOB - branch protection in imsc-hrm// 16:44:28 i/atsushi, you wanted to discuss (AOB)/Topic: AOB - branch protection in imsc-hrm 16:45:51 i/.. I have also another question/Subtopic: Which Licence? 16:46:39 i/Nigel: Any other questions before we take it further?/Subtopic: Timeline for publication 16:47:01 i/Atsushi: We may be able to configure streamlined/Subtopic: Streamlined publication 16:56:42 i/PROPOSAL: Request transition/Subtopic: Transition Request 16:56:48 rrsagent, make minutes 16:56:48 I have made the request to generate https://www.w3.org/2021/10/14-tt-minutes.html nigel 17:01:27 Present- mike 17:01:30 Present+ Mike 17:01:48 scribeOptions: -final -noEmbedDiagnostics 17:01:53 zakim, end meeting 17:01:53 As of this point the attendees have been Andreas, Nigel, Atsushi, Pierre, Cyril, Mike 17:01:55 RRSAgent, please draft minutes v2 17:01:55 I have made the request to generate https://www.w3.org/2021/10/14-tt-minutes.html Zakim 17:01:58 I am happy to have been of service, nigel; please remember to excuse RRSAgent. Goodbye 17:02:02 Zakim has left #tt