1607260 - Website evades blocking of autoplay with sound

Status: RESOLVED WONTFIX

(Core :: Audio/Video, defect)

Description

[Felix Lawrence]

smh.com.au is evading blocking of autoplay video with sound.

I have media.autoplay.default = 5 (non-default value of 5 is probably not necessary but I haven't checked) on nightly 73 (I also noticed this on release v71)

Steps to reproduce:

1. Visit smh.com.au
2. Click on an article that has a video in it (most of them do)
3. Scroll down in the article to the video
4. Observe that when the timer counts down from 5, the video starts playing, with sound.

This doesn't happen if you instead open the article in a new tab, or navigate directly to it.

Comment 1

[Alastor Wu [:alwu]]

When you click on the page, the page has been activated by clicking then it would be allowed to play afterward. That is an expected behavior for our user-gesture-activation blocking policy. Setting media.autoplay.default to 5 just means we would block both audio and video before the page get activated by user gesture.

If you want the autoplay only happen when you click something, you can try to set the pref media.autoplay.enabled.user-gestures-needed to false to see if that meets your requirement.

Comment 2

[Felix Lawrence]

Ah, but the point was that Step 2 involves clicking a link that appears to load a new page. So I would have expected this new page to require activation - else this is a pretty big loophole, that any news site can slip through in order to push noisy videos onto their readers.

Comment 3

[Alastor Wu [:alwu]]

Some websites (like Youtube) would reuse same document for the navigation. Although it looks like navigating to the new page, it's actually still in the same page but with new html elements.