Sound isn't synchronizing with video in a trailer with Dolby Atmos headphone virtualization Windows 10 app.

https://www.imdb.com/title/tt18257464/

Tried to view a trailer and thought it was dubbed at first.  Saw the same issue on a few in a row, then realized I'd kept the Windows 10 headphone virtualization on.  And that your playback method seems to ignore the extra processing delay it introduces.

I'm 99% sure the Windows 10 store app from "Dolby" (their Atmos headphone virtualization) is delaying the audio.  It adds 200ms of latency... from about 100ms to more like 300 in the browser page I tested from).  I bought it and the DTS Unbound app for the other typical encoding possibility.

Native video players (like MPC-HC with LAV Filters) have settings to shift audio playback to account for differences in processing latency.  Like how some TV's take longer to display an image than "computer monitors" would.  I see no such option here.  And normally the native players fix themselves automatically anyway.  I assume the Dolby thing tells the rest of the playback stack about it's need for extra processing time, so they can make the visual changes synchronize with the appropriate sound.

I'm using Firefox on Windows 10, NVIDIA 1080 ti, i7-4790k CPU (4.2-4.4GHz turbo, 4c/8t), 32GB RAM...  everything is updated to the latest released versions (automatic updates I trigger manually to be sure).  Many people use WebKit based browsers so this might be the issue (rendering engine for Edge, Chrome, Safari, etc).  Firefox is one of the biggest non-WebKit browsers I know of (Is their's "Quantum" or "Gecko"? I forget their current codename).  Last I saw 5% of the traffic on the web is still through it.  And I won't use a browser without Ad blocking capabilities (uBlock Origin with many filters active... I don't use the privacy filters, but most of the rest are on).

No idea if this is true on any other site(s), but YouTube Music synchronizes fine.  I've played a number of music videos where I watch while listening, and would have noticed sync issues.  Pretty sure YouTube proper was the same.  That points to Firefox functioning at least some of the time.