1578609 - Media element didn't start loading from its source element child with type=""

Status: RESOLVED FIXED

(Core :: Audio/Video, defect, P2)

Description

[Karl Dubost💡 :karlcow]

A test case
https://codepen.io/webcompat/pen/pozdjPG

this source code.

<video>
  <source src="http://distribution.bbb3d.renderfarming.net/video/mp4/bbb_sunflower_1080p_60fps_normal.mp4">
</video>

<video>
  <source src="http://distribution.bbb3d.renderfarming.net/video/mp4/bbb_sunflower_1080p_60fps_normal.mp4" type="">
</video>

On Firefox,

1. if we do not specify anything, the video is displayed
2. If we specify an empty type='', the video is not being displayed.

On Chrome the video is always displayed.

Comment 1

[Alastor Wu [:alwu]]

NI myself for further investigation.

Comment 2

[Alastor Wu [:alwu]]

Attachment: Bug 1578609 - part1 : only check source element's type attribute when it's not empty.

If source element's type is empty, it's equal to not having any type, so we won't have to check can play type.

Comment 3

[Alastor Wu [:alwu]]

Attachment: Bug 1578609 - part2 : add test 'test_load_source_empty_type.html'.

Comment 4

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Empty type is an invalid mime type, but the spec leaves some room for how we should interpret those in this case: https://html.spec.whatwg.org/multipage/media.html#loading-the-media-resource:attr-source-type

With this change I would say we're interpreting the spec to say "if the type parses and a mime type, and the UA definitely doesn't support it, then fail, otherwise continue". In this case the empty MimeType is not certain to be unsupported, so we try our best, which seems reasonable.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6d54bc134d27
part1 : only check source element's type attribute when it's not empty. r=bryce
https://hg.mozilla.org/integration/autoland/rev/5a7c394c6f0f
part2 : add test 'test_load_source_empty_type.html'. r=bryce

Comment 6

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/6d54bc134d27
https://hg.mozilla.org/mozilla-central/rev/5a7c394c6f0f

Comment 7

[Liz Henry (:lizzard) (relman/hg->git project)]

Is this something you would like to uplift to 70? Are there examples out there of people reporting this issue? We can also leave it to ride the trains with 71.

Comment 8

[Alastor Wu [:alwu]]

I didn't see any other reporting similar issue like this, and it's also not a common issue. So we can probably let it stay on 71.