IRC log of mediawg on 2023-12-12

Timestamps are in UTC.

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logging to https://www.w3.org/2023/12/12-mediawg-irc
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22:00:28 [cpn]
Meeting: Media WG
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chair: Chris_Needham
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present+ Chris_Needham, Francois_Daoust, Bernard_Aboba, Jer_Noble, Jean-Yves_Avenard, Mark_Foltz, Eugene_Zemtsov, Tommy_Steimel
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22:05:06 [cpn]
Slides: https://docs.google.com/presentation/d/176UKXIpelSAEJ58xReZnFSPQvaDqI4bD3RSOdzGtBZo/edit
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Present+ Mark_Foltz
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Present+ Eugene_Zemtsov
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RRSAgent, draft minutes
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I have made the request to generate https://www.w3.org/2023/12/12-mediawg-minutes.html tidoust
22:28:41 [tidoust]
RRSAgent, make logs public
22:30:48 [tidoust]
Slideset: https://lists.w3.org/Archives/Public/www-archive/2023Dec/att-0003/W3C_Media_WG_Meeting_2023-12-12.pdf
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[slide 3]
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[slide 4]
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[slide 5]
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[slide 6]
22:35:08 [tidoust]
scribe+
22:35:40 [tidoust]
cpn: First and third look like browser bugs. Second one is interesting as browser returns an object that does not exist in the spec.
22:36:02 [tidoust]
jernoble: We thought we raised that a long time ago and had resolved to do that.
22:36:35 [tidoust]
... We implemented support for it, but I guess it never made it into the spec. We should go back and figure out what was proposed.
22:37:04 [tidoust]
... How do you know the properties you pass in are understand by the user agent? The solution was to pass them back. Forward-compatibility idea.
22:37:12 [tidoust]
... Definitely something that we need to fix.
22:37:29 [tidoust]
[slide 7]
22:37:46 [tidoust]
cpn: I started to go through open issues with a view to prioritizing them.
22:37:55 [tidoust]
... I'd like to get a sense of that from the group.
22:38:31 [tidoust]
... Which of those do we want to focus on?
22:38:56 [tidoust]
... Example of an API proposal to do configuration transition which we never settled on. There is a PR but three different proposals on the API shape.
22:41:01 [tidoust]
... Alpha channels, Dolby vision type things, that were things that we talked about at TPAC in particular. And there was a proposal to add some sort of registry with identifiers that let you talk about Dolby Vision.
22:42:25 [tidoust]
mfoltz: Unfortunately, Google folks focused on Media Capabilities couldn't attend the call today. Making sure that these are all captured as issues, and then discussing whether they're in scope or extending the scope. And then I can take things back internally.
22:42:47 [tidoust]
... Just using issue labels might be useful.
22:43:41 [tidoust]
cpn: [sharing a slideset with a list of such issues]. Some clarification about what we mean by variable bitrate and constant bitrate.
22:43:52 [tidoust]
... Are we using MIME sniff properly.
22:44:26 [tidoust]
... A number of things around WebRTC integration.
22:44:48 [tidoust]
... Big feature request around transition (what I mentioned before)
22:45:07 [tidoust]
... PR #107 just needs a review
22:45:22 [tidoust]
... There's the whole capability fingerprinting tihng
22:45:28 [tidoust]
s/tihng/thing
22:45:42 [tidoust]
... Question on how it relates to WebCodecs, can we provide an example.
22:46:07 [tidoust]
... Number of questions about the relationship through Media Capabilities in terms of decode capabilities and display capabilities.
22:46:41 [tidoust]
... I think we said that display capabilities were out of scope, to be solved elsewhere, e.g., attached to Screen. Needs review at least.
22:46:57 [tidoust]
... #136 is the HDR metadata thing we were just talking about.
22:47:48 [tidoust]
... #113 is an issue coming from people working on HbbTV with constrained devices and you want to know whether you can decode more than one stream at once and with what parameters.
22:48:01 [tidoust]
... A couple of questions around CMAF in particular.
22:48:54 [tidoust]
present+ Marcos_Caceres
22:49:15 [tidoust]
... [going through other issues]
22:49:41 [tidoust]
... #99 is a general issue about supplemental data in CMAF (example of 608/708 captions). Should it be in scope?
22:50:11 [tidoust]
jernoble: The question is whether if you give a stream with 608/708 captions, whether you get captions?
22:50:20 [tidoust]
cpn: We need to clarify that.
22:50:53 [tidoust]
... There's another spec about mapping in-band tracks.
22:51:18 [tidoust]
... Clarifications about the video frame rate (#95). What if you've got a variable frame rate.
22:51:59 [tidoust]
... A lot of these were answered but we've never closed the issues with a resolution to change the spec or say that you can do it without changes, or that it is out of scope.
22:52:22 [tidoust]
... #88 is an IDL thing that needs somebody to take a close look at.
22:52:48 [tidoust]
... #73 is about audio channels. What we have at the moment is a string. How do you express more complex audio channel configurations?
22:53:02 [tidoust]
... Interesting to see what current implementations do.
22:53:45 [tidoust]
... Also what happens to audio streams? Do they get downmix to stereo in which case you might prefer to provide stereo directly?
22:54:06 [tidoust]
... As far as I can tell, Web Audio has a number of channels, but does not go into more details.
22:54:25 [tidoust]
jernoble: Audio is one part where we mixed decoding and rendering.
22:54:55 [tidoust]
... It talks about the current audio device, which is dynamic. We did that because we did not have a better place to do the work, I think.
22:55:05 [tidoust]
... Perhaps not a good idea, but worked at the time.
22:56:04 [tidoust]
... Some other spec allows you to get more information about the output capabilities.
22:56:28 [tidoust]
cpn: Audio Output Device API? I glanced at it, it does not really say anything about capabilities.
22:57:25 [tidoust]
mfoltz: If issues were filed by folks in this group, maybe we can ask them to label them as v1 or vnext issues, and then I can look whether editors can take a look at them.
22:57:52 [tidoust]
cpn: If there's somebody who would like to become editors, we could use somebody to help.
22:58:08 [tidoust]
mfoltz: I'll see what I can do to find people.
22:58:20 [tidoust]
cpn: Some of these issues have been around for a number of years.
22:58:53 [tidoust]
... I can probably do that passthrough to identify what is in v1 scope and what is a feature request.
22:59:04 [tidoust]
... And then I can send that through to you.
22:59:14 [tidoust]
... I don't think we have time to go through more of this stuff.
23:00:49 [tidoust]
cpn: See you in the new year!
23:00:54 [tidoust]
RRSAgent, draft minutes
23:00:55 [RRSAgent]
I have made the request to generate https://www.w3.org/2023/12/12-mediawg-minutes.html tidoust