Re-introduction of Media Queries (and srcset/sizes) in Source Elements

[jernoble]

WebKittens

@jernoble, @ericcarlson, @jyavenard

Title of the spec

HTML Video Element: Proposal For Reintroduction of Media (and srcset/sizes) in Source Elements

URL to the spec

https://html.spec.whatwg.org/

URL to the spec's repository

https://github.com/whatwg/html

Issue Tracker URL

whatwg/html#6363

Explainer URL

https://github.com/filamentgroup/html-video-responsive

TAG Design Review URL

No response

Mozilla standards-positions issue URL

No response

WebKit Bugzilla URL

No response

Radar URL

No response

Description

The GitHub issue above tracks the re-introduction of media queries to <source> used by <audio> and <video> in the resource selection algorithm for media elements.

Media Queries (via the media= attribute to <source>) were previously specified in HTML, but were removed from the spec. Subsequent standardization of the <picture> element re-used the <source> element, including the media= attribute. Currently, the resource selection algorithm makes no mention of the media= attribute, and the specification of the source element explicitly forbids the use of srcset, sizes, and media attributes when the source's parent is a media element.

WebKit never removed support for Media Queries from its implementation of HTMLMediaElement. This issue tracks WebKit's public position on the re-inclusion of Media Queries, as well as the addition of support for srcset and sizes.

[jernoble]

Implementer hat on, I would argue WebKit should support this proposed re-introduction. We never removed support for media queries, but as the only implementor and with that implementation existing outside the specification, most authors resort to javascript for the same functionality.

[hober]

Given @jernoble's remarks, I plan to mark this as position: support in a week unless this discussion takes an unforeseen turn.