Yesterday I bought this game to be able to play on my mac via wrappers wineskin.
Everything seemed to work except for one thing, they had cutscenes audio / video out of sync,
Since I had to work hard to find the solution I will post here:
http://www.mediafire.com/download/yvdxcw7663v1k67/dsound.dll
Download this dll and put it in the system32 folder of windows.

I do not know if this fix also works on windows but it definitely works on various wrapper for mac found online of this game.
I hope it will help someone.

Thanks!
This fixed the audio out of sync for me too (using wine on ubuntu).

Thank you. This also seems to have fixed the issue for me. Running the game through Wine 1.7.54 (installed with Playonlinux) on Linux Mint 17.2 64 bit.

Sorry for the late answer... I think it's an old windows dll (I don't really remember where I find it... I just remeber it was an official dll).
also if you use a wrapper on linux/mac modify a dll is not so important. I don't know if on windows it's necessary (maybe it's not), but if it's necessary you can just backup your dll, play the game, put the original dll back.
I uploaded it to mediafire so don't worry about that (I did find it in another place... maybe a windows xp virtual machine... I really cannot remember).

Wanted to say that this is still working in Linux with Wine.
Was having a heck of a time and it wouldn't work right even in a VM in Virtualbox.

Replacing this file and working in Wine 1.8 with PlayOnLinux.

This tweak still needed and works in 2019 with Wine 4.x, thank you!

Is this the same .dll file that is provided by your git repository?

Yes

I link to your GitHub repository from ./play.it documentation on how to work around audio issues for Beyond Good & Evil, I hope it is OK with you: Beyond Good and Evil - Audio-related issues

Hello, this solution posted on reddit worked for me in Windows 10. Cutscenes are now in sync with audio:

https://www.reddit.com/r/pcgamingtechsupport/comments/6h55m6/beyond_good_and_evil_runs_too_fast_uplay_version/