IRC log of mediawg on 2021-11-09

Timestamps are in UTC.

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logging to https://www.w3.org/2021/11/09-mediawg-irc
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RRSAgent, draft minutes
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I have made the request to generate https://www.w3.org/2021/11/09-mediawg-minutes.html tidoust
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RRSAgent, make logs public
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Meeting: Media WG Teleconference
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Agenda: https://github.com/w3c/media-wg/blob/main/meetings/2021-11-09-Media_Working_Group_Teleconference-agenda.md
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Chair: Chris, Jer
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Present+ Francois_Daoust, Alastor_Wu, Chris_Needham, Cyril_Concolato, Eric_Carlson, Jer_Noble, Mark_Watson, Matt_Wolenetz, Peng_Liu,
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present+ Greg_Freedman
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present+ Thomas_Guilbert
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present+ Jean-Yves_Avenard
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present+ Gary_Katsevman, Chris_Cunningham
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22:07:14 [chcunningham]
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scribe: chcunningham
22:07:26 [cpn]
scribe+ cpn
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Topic: requestVideoFrameCallback
22:08:19 [tidoust]
-> Moving video.requestVideoFrameCallback spec to media WG https://github.com/w3c/media-wg/issues/34
22:08:24 [chcunningham]
tguilbert: current state is that rVFC is shipped in chrome
22:08:37 [chcunningham]
... get a callback next time video frame is presented to compositor.
22:08:50 [chcunningham]
... adds metadata about that frame that is otherwise unavailable. including rtc things
22:09:09 [chcunningham]
... can be used for measuring glass-to-glass latency
22:09:31 [chcunningham]
... can be used to get callbacks at rate of video frame rate
22:09:33 [hober]
present+
22:09:43 [chcunningham]
... no other browsers implemented yet. Safari asked a few questions
22:10:08 [chcunningham]
... up next: considering adding an extra parameter to get the actual VideoFrame (webcodecs interface)
22:10:46 [chcunningham]
cpn: seen some suggestion from html folks that this should move to html
22:11:19 [jernoble]
q+
22:11:28 [tidoust]
ack jernoble
22:12:12 [chcunningham]
jer: what are the use cases for emitting a WebCodecs frame? beyond that: not seeing anything that media wg must own here, unless we take over all of media element from html
22:12:52 [chcunningham]
cpn: would it be acceptable for html to reference webcodecs?
22:12:57 [chcunningham]
tguilbert: unclear
22:13:35 [chcunningham]
tguilbert: getting the frame that was painted adds feature not currently feasible with WebCodecs
22:14:08 [chcunningham]
... can presently construct VideoFrame(<video>), but this affords means to be confident that the frame they have metadata for is the frame they're constructing
22:14:43 [MattWolenetz]
q+ to say some clarification on a rVFC use-case
22:15:09 [chcunningham]
jer: could we spec webcodecs to say that if you paint during this run loop that its syncronized w/ what you might get from rVFC?
22:16:19 [chcunningham]
tguilbert: no way to address these races w/ WebCodecs without synchronizing multiple threads
22:16:31 [chcunningham]
... happy to follow up on these technical details
22:17:14 [chcunningham]
cpn: currently not in wg, IIUC we would need to recharter to take this on
22:17:37 [chcunningham]
... option open to us. should we run a cfc on the venue?
22:18:08 [chcunningham]
tguilbert: youenn initially asked this, said he would be fine to move to html
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22:18:10 [tidoust]
ack MattWolenetz
22:18:10 [Zakim]
MattWolenetz, you wanted to say some clarification on a rVFC use-case
22:19:38 [cpn]
chcunningham: This API, were it extended, it would give you the metadata it's describing
22:21:08 [cpn]
... What are the practical implications?
22:21:35 [cpn]
cpn: WG provides a venue for discussion. HTML you'd work with the editors there to integrate the spec
22:22:23 [cpn]
chcunningham: I'm happy to move to HTML, seems straightforward from a process standpoint
22:22:54 [chcunningham]
cpn: can record that as proposed resolution
22:23:13 [chcunningham]
... give folks offline chance to weigh in
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22:23:39 [chcunningham]
... no formal steps from w3c pov since this isn't yet in WG
22:24:35 [chcunningham]
RESOLUTION: lets move this to HTML wg
22:25:08 [cpn]
Topic: Autoplay Policy Detection
22:25:36 [chcunningham]
cpn: alwu has been putting together a draft. can you summarize current state, open questions?
22:26:32 [chcunningham]
alwu: Draft available. API lets devs know if they can play. Underlying decision currently very UA specific (engagment, user gesture, ...)
22:26:50 [chcunningham]
... so this lets devs know whether they should do things like present image vs start video w/ muted audio
22:26:55 [chcunningham]
... several open questions
22:27:11 [cpn]
https://alastor0325.github.io/autoplay/
22:27:11 [chcunningham]
... 2 apis. 1 on media element. another on the document.
22:27:33 [chcunningham]
alwu: for media element, policy can differ by browser.
22:27:43 [chcunningham]
... for web audio, it is actually spelled out in the spec
22:28:14 [chcunningham]
... previous consenus: web audio folks want to use document api
22:28:25 [chcunningham]
... but my pov, document API is not very clear
22:29:16 [cpn]
q?
22:29:41 [chcunningham]
... for ex: stickiness of user gesture may not describe web audio policy (scribe: a little lost)
22:30:34 [chcunningham]
... current API proposal isn't a great fit to accommodate all the various browsers behaviors
22:30:52 [chcunningham]
... one path may be to put a policy attribute on AudioContext
22:32:36 [chcunningham]
jer: one path might be to make a new API that consumes <audio> or WebAudio as input and gives answer
22:32:56 [chcunningham]
alwu: we're open to it, but not sure how other participants feel
22:33:27 [cpn]
chcunningham: From the Chrome point of view, you'd need to talk to Frank, who's not on this call
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22:34:28 [chcunningham]
gkatsev: from user perspective, an API where you could pass things in seems reasonable
22:34:37 [chcunningham]
... nice consistency
22:35:21 [cpn]
chcunningham: In the previous discussions, are you converging on a design, or are there any sticking points?
22:36:01 [chcunningham]
alwu: current state on PR. dale reviewed, was feeling positive, but left for PTO
22:37:03 [cpn]
chcunningham: Frank is our representative for this topic. So you're now waiting for review feedback from Frank?
22:37:47 [cpn]
... I'll follow up with Frank
22:39:15 [chcunningham]
cpn: suggestion on PR - it's quite long with lots of threaded comments. you may try merging it and then taking individual points of feedback
22:39:22 [chcunningham]
... as editor you have that freedom
22:40:29 [cpn]
chcunningham: We had similar with Web Codecs. I tried to have conversations in GitHub issues. Chris's suggestion is fine if it helps
22:43:17 [chcunningham]
cpn: HTML editors asked whether this should be integrated into HTML.
22:43:43 [chcunningham]
... could be standalone if we pursue what Jer suggested
22:43:48 [jernoble]
q?
22:43:50 [jernoble]
q+
22:44:04 [chcunningham]
... my view: lets iterate on the spec a bit more first
22:44:57 [chcunningham]
wolenetz: another consideration is review audience - which group is best to review
22:45:19 [chcunningham]
jernoble: happy to have it media for now, move to html later if needed
22:46:12 [cpn]
Topic: Process 2021 and registries
22:46:49 [chcunningham]
cpn: w3c process introduced a new "registry" track
22:46:58 [MattWolenetz]
q+ to ask about registry and patent policies for externally referenced items (codecs, formats, etc)
22:47:00 [chcunningham]
... are we automatically adopting this process?
22:47:49 [chcunningham]
tidoust: I think so. And I think we're allowed to update current registries without changing our charter. But I need to double check.
22:48:20 [chcunningham]
cpn: so rather than calling documents "notes", we call the "registry" or "registry entry"
22:48:24 [chcunningham]
... are there additional requirements?
22:48:49 [MattWolenetz]
q+ to ask also about "and must not contain any requirements on implementations."
22:48:55 [chcunningham]
tidoust: no. process defines exactly what registries should contain, but I think we're already meeting those requirements
22:50:05 [chcunningham]
cpn: so for WebCodecs registry, should be straightforward. Just changing the title? Are there other editorial tasks?
22:50:39 [chcunningham]
tidoust: should be just a handful of minor edits to the document
22:50:42 [tidoust]
https://www.w3.org/2021/Process-20211102/#switching-tracks
22:50:43 [MattWolenetz]
q+ to ask further about provision of registry data (required in the report or section) -- these are currently distinct notes, e.g. MSE ISOBMFF vs MSE WebM etc.
22:51:32 [chcunningham]
cpn: is there an option to continue w/ notes? or are we expected to switch tracks?
22:52:08 [chcunningham]
tidoust: no strict expectation. idea is transition should make our lives easier.
22:52:35 [tidoust]
q- jernoble
22:52:38 [tidoust]
ack MattWolenetz
22:52:38 [Zakim]
MattWolenetz, you wanted to ask about registry and patent policies for externally referenced items (codecs, formats, etc) and to ask also about "and must not contain any
22:52:41 [Zakim]
... requirements on implementations." and to ask further about provision of registry data (required in the report or section) -- these are currently distinct notes, e.g. MSE
22:52:41 [Zakim]
... ISOBMFF vs MSE WebM etc.
22:52:42 [chcunningham]
wolenetz: a few questions
22:52:58 [chcunningham]
... 1. what are the patent requirements for new registry vs current notes?
22:53:23 [chcunningham]
... I read that the new registry documents are still non normative
22:53:59 [chcunningham]
... 2. confused about how registry avoids imposing requirements on implementations
22:54:51 [chcunningham]
tidoust: re: 1, registries have no impact on patent policy
22:55:23 [chcunningham]
... re: 2, I don't see any requirements in MSE registry. is there one?
22:56:09 [chcunningham]
... idea is that registry document itself should not have any normative requirements
22:56:40 [chcunningham]
wolenetz: we see registry mentions requirements for registration entries. is that a requirement
22:56:54 [chcunningham]
tidoust: no. that's not a requirement on implementation, just on registration
22:58:17 [chcunningham]
wolenetz: registrations are currently in separate documents (e.g. webm byte stream). is this ok w/ new process?
22:58:29 [MattWolenetz]
q-
22:58:42 [chcunningham]
tidoust: yes, no need to change those documents. the new process is mostly about the registry table and adding things to registry
22:59:33 [chcunningham]
cpn: is there any additional work to publish things that are already published?
23:00:02 [chcunningham]
tidoust: good point. suggest that we start w/ WebCodecs since we haven't published that one yet.
23:00:27 [cpn]
chcunningham: I don't object, but haven't looked at it closely
23:01:18 [cpn]
... I expect to be ready to run the CfC later this week
23:02:12 [chcunningham]
cpn: wrapping up, next call is on 14th of December
23:02:17 [chcunningham]
... thanks!
23:02:46 [cpn]
rrsagent, draft minutes
23:02:46 [RRSAgent]
I have made the request to generate https://www.w3.org/2021/11/09-mediawg-minutes.html cpn
23:02:57 [cpn]
rrsagent, make log public
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