1517166 - Reloading an iframe can circumvent autoplay blocking

Status: RESOLVED INVALID

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

Description

[Andreas Pehrson [:pehrsons]]

(As written by Berend De Schouwer in bug 1504180 comment #6)
> I currently see this on cyclingtips.com (which embeds vimeo videos).  The
> video starts playing without permissions to play, and it seems to do this
> whether I set autoplay to "always ask" or "don't autoplay"
> 
> I cannot repeat it on cnn.com or foxnews.com.  Both those sites ask
> permission for me.
> 
> cyclingtips uses an iframe.  Opening the iframe alone does not autoplay.

I can confirm this.

STR:
1 Load https://jsfiddle.net/pehrsons/239nowv7/ (autoplay blocked)
2 Click "Run" to reload the iframe.
Expected: Video does not start autoplaying.
Actual: Video starts autoplaying with sound.

Comparing to the iframe-less https://player.vimeo.com/video/259411563?autoplay=1, this is always blocked.

Comment 1

[Andreas Pehrson [:pehrsons]]

Alastor, can you take a look?

Comment 2

[Alastor Wu [:alwu]]

When you click "run", you've already activated the whole document tree with user gesture, the policy we implement is that when you activate any document, it would also activate other documents on the same document tree even if they're in the different origin. That was implemented in bug1470346.

If document has been activated by user gesture, autoplay is allowed.