Register story page level background-audio.

[gmajoulet]

#27366 has an optimization to run the registerAllMedia_() only once. But the background-audio is built and added to the DOM on layoutCallback, which happens after the first call to registerAllMedia_() for pages with distance > 2.

Fixes #27573, #27779

[Enriqe]

Thanks for the quick fix!

[newmuis]

Should the background-audio be built on layout instead of build? Can we build an amp-audio instead of an audio so that it's privacy-preserving?

(edit: genuine question, I don't know the answer)

[gmajoulet]

If I had to implement this feature today I think my first instinct would be to do it the way you're suggesting. It has many cons though: you'd still have race conditions with prerendering like the one Malte fixed today for videos, our media pool code might run in between the build and layoutCallback. You'd also need to load the amp-audio extension, adding more asynchronous things (and bytes) in the mix.

We can track this work into another ticket if you want us to investigate the pros/cons further! This one is bringing us back to where we were.

[brantgarvey]

Hi @gmajoulet & @Enriqe, sorry I'm new to Github, so forgive me if I ask silly questions, but I'm exploring with amp and amp stories.

I ran into the problem of having background audio not playing on page 3 of my story and I wanted to know how I can implement the change you have created here?

Here is the project I'm currently working on.

Cheers,
Brant

[gmajoulet]

Hi,
This pull request is not yet available on production, as it takes several days to completely roll out. It should be available tomorrow though, you can expect things to start working automatically for your story!
Please let us know if you need anything else.

[brantgarvey]

Awesome @gmajoulet thanks heaps for your help with this bug!