Re: [csswg-drafts] [css-mediaqueries-5] Clarifications on [video-]dynamic-range MQs (#6793)

The CSS Working Group just discussed `[css-mediaqueries-5] Clarifications on [video-]dynamic-range MQs`.

<details><summary>The full IRC log of that discussion</summary>
&lt;fantasai> Topic: [css-mediaqueries-5] Clarifications on [video-]dynamic-range MQs<br>
&lt;fantasai> github: https://github.com/w3c/csswg-drafts/issues/6793<br>
&lt;fantasai> florian: We have 2 MQ which are similar, dynamic-range and video-dynamic-range<br>
&lt;fantasai> florian: 2 issues in 1 here<br>
&lt;fantasai> florian: one is primarily editorial, doing poor job of explaining the difference between these two queries<br>
&lt;fantasai> florian: notion of video plane is fairly rare concept that relates to TVs and how they have unusual screen buffer impls that we can query separately<br>
&lt;fantasai> florian: core question raised in this issue, besides clarification<br>
&lt;chris> +1 to that editorial clarification<br>
&lt;fantasai> florian: is that we have 2 values: high and standard<br>
&lt;fantasai> florian: You might assume, and this apparently is what Safari did, that any device will match standard and some will match high as well<br>
&lt;fantasai> florian: this is not how currently specced, though<br>
&lt;fantasai> florian: devices expected to match one or the other<br>
&lt;fantasai> florian: not standard and high simultaneously<br>
&lt;chris> q+<br>
&lt;fantasai> florian: The query about color-gamut does behave differently, it has 3 values<br>
&lt;fantasai> florian: and these are additional, when you match broader gamut you also match narrower one<br>
&lt;fantasai> florian: unclear what we should do here<br>
&lt;Rossen_> q?<br>
&lt;Rossen_> ack chris<br>
&lt;fantasai> chris: I agree, media capability does the same thing, of using supersets<br>
&lt;fantasai> chris: overall I think it's a better model, think we can easily make spec say that<br>
&lt;fantasai> chris: the reason to do it is that when we add super-high later on, we want it to be a superset that still passes high<br>
&lt;fantasai> chris: so I think we should change the spec; not because it's what implemented, but because it makes more sense<br>
&lt;fantasai> dbaron: Wanted to add, think there's a 3rd issue<br>
&lt;fantasai> dbaron: currently wording in spec about combo of UA and output device<br>
&lt;fantasai> dbaron: needs clarification what the UA part of it means<br>
&lt;chris> see also https://w3c.github.io/media-capabilities/#hdrmetadatatype<br>
&lt;fantasai> dbaron: definition of high says, combination of UA and output device fulfill all the following criteria<br>
&lt;fantasai> dbaron: there are a number of ppl in the issue saying that the UA bit should be ignored, and should only be query about the output device<br>
&lt;Rossen_> ack dbaron<br>
&lt;fantasai> dbaron: but if this is question of UA capability, which are you considering if UA can do for some things but not others<br>
&lt;florian> q?<br>
&lt;fantasai> dbaron: e.g. videos but not images, or ...<br>
&lt;chris> q+ to also mention HDR is opt-in and can change dynamically<br>
&lt;fantasai> florian: I suspect querying device and not UA is useless<br>
&lt;fantasai> florian: because if the UA isn't able to access the capability, it's not helping you<br>
&lt;fantasai> florian: but if capability varies within UA, that's a problem<br>
&lt;fantasai> Rossen_: Is one a superset of other? Is UA superset of device?<br>
&lt;fantasai> dbaron: I wouldn't think of it that way<br>
&lt;fantasai> florian: We're querying union of both<br>
&lt;fantasai> florian: need both UA and device to be capabe<br>
&lt;fantasai> chris: Also, HDR capability can vary over time<br>
&lt;fantasai> chris: high power usage<br>
&lt;fantasai> chris: so off by efault<br>
&lt;fantasai> chris: so need to know that it can change<br>
&lt;fantasai> chris: One, is the device capable of HDR mode, and then two, is it in that mode?<br>
&lt;Rossen_> s/Is UA superset/Is UA subset/<br>
&lt;fantasai> chris: we are mixing those two up<br>
&lt;fantasai> florian: we do<br>
&lt;Rossen_> ack chris<br>
&lt;Zakim> chris, you wanted to also mention HDR is opt-in and can change dynamically<br>
&lt;Rossen_> ack fantasai<br>
&lt;drott> fantasai: we should take a resolution to change the query to superset model<br>
&lt;drott> fantasai: multiple things to be clarified<br>
&lt;drott> fantasai: let's ask editor to go back to the thread to work out results<br>
&lt;drott> fantasai: a lot of the clarifications are straightforward<br>
&lt;drott> fantasai: need a resolution to change the media queries<br>
&lt;fantasai> florian: Don't quite agree, question of capability or in HDR mode currently<br>
&lt;fantasai> florian: or videos vs images etc.<br>
&lt;fantasai> florian: not quite clarification, is change in functionality<br>
&lt;fantasai> florian: puzzle how to answer if we don't change the syntax<br>
&lt;chris> q+<br>
&lt;fantasai> florian: so can do things fantasai highlighted, but not enough to solve the issue<br>
&lt;Rossen_> ack chris<br>
&lt;fantasai> chris: media capabilities spec talks about capability, "can the device do it"<br>
&lt;fantasai> chris: if we clarify that way, need the other query as well<br>
&lt;fantasai> chris: the capability and concrete "am I in this mode" are separate<br>
&lt;fantasai> florian: Is it expected to remain this way?<br>
&lt;fantasai> chris: especially for mobile, definite power drained<br>
&lt;fantasai> chris: can be switched automatically, doesn't require user action<br>
&lt;fantasai> chris: but there needs to be a capability<br>
&lt;fantasai> chris: and need to know which mode you're in<br>
&lt;drott> fantasai: i think we should spec as being able to use the switch<br>
&lt;drott> fantasai: from a media queries point of view, how are we styling the document - many of those questions on depend on current mode<br>
&lt;drott> fantasai: [missed parts]<br>
&lt;fantasai> florian: what do we do about if UA can do for images and video but not CSS colors?<br>
&lt;fantasai> florian: or some other variation?<br>
&lt;fantasai> florian: should we consider the UA does or does not fulfill the criteria?<br>
&lt;fantasai> florian: or do we think about query in a different way<br>
&lt;fantasai> florian: I haven't thought about deeply, but maybe you would have high-dynamic-range: video | canvas | etc.<br>
&lt;fantasai> florian: and would get something true if that specific thing is in HDR mode<br>
&lt;fantasai> Rossen_: sounds like a convesation to continue in GH<br>
&lt;fantasai> Rossen_: and doesn't seem we're ready to resolve just yet<br>
&lt;fantasai> Rossen_: propose we stop here, and then after working out proposal in issue, bring back and we'll record a resolution<br>
&lt;fantasai> Rossen_: but hopefully attracted some help on this issue<br>
</details>


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Received on Wednesday, 10 November 2021 17:27:07 UTC