1481322 - Videos start autoplaying after scroll up in Huffington post

Status: RESOLVED WORKSFORME

(Core :: Audio/Video: Playback, defect, P3)

Description

[Eitan Isaacson [:eeejay]]

STR:

1. Go to a huffington post article like: 
2. The video at the top of the article does not autoplay. That is good.
3. Scroll down the page.
4. Scroll back up the page.

Result: Video starts playing.
Expected: Video should continue to be blocked.

The play() probably happens through a 'scroll' event that is "user initiated", but really feels random. I'm not sure how to fix this.

Comment 1

[Alastor Wu [:alwu]]

Hi, Eitan,

Do you click any button on the prompt which asks you whether you want to allow this site to autoplay?

Now the site could only be allowed to autoplay after 
(1) user clicks "Allow" in prompt
(2) user activates the page by specific user gestures (mouse click, keboard press)

Thank you!

Comment 2

[Eitan Isaacson [:eeejay]]

Autoplay is blocked on that site for me.

What I think is happening is that the video starts playing from a 'scroll' event handled that is considered user initiated.

Comment 3

[Alastor Wu [:alwu]]

No, we don't support 'scroll' event as a user activation gestures [1].

If the video starts playing, it means that it is muted, volume 0, allowed by prompt or activated by user gestures defined in [1].
 
[1] https://searchfox.org/mozilla-central/rev/51268dcbdff0f6f4a5cff7986df0f616efc5bcfd/dom/events/EventStateManager.cpp#919

Comment 4

[Eitan Isaacson [:eeejay]]

OK, so I am not sure how this happens. Did you try my STR above?

Comment 5

[Eitan Isaacson [:eeejay]]

I can look into this more tomorrow too.

Comment 6

[Alastor Wu [:alwu]]

Yes, I has tried the STR in comment0, but the video didn't start.

Comment 7

[Alastor Wu [:alwu]]

I still can't reproduce this issue on today's Nightly 64.0a1 (2018-09-13) (64-bit), so close this bug.
Please feel free to reopen this bug if you see the issue again.