Video and audio synchronization

Dear all,

The community has helped me a lot ^^
I really want to understand about Jitsi video and audio flow. So there is a question I was wondering.
How does audio and video flow transmit in a call? I have searched for video and audio synchronization in sfu architecture on google but still can’t find anything.
As I know the video and audio flow is dependent from each other (in Last-N configuration the video can be selected but audio is always transmitted). So what is the mechanism for audio and video synchronization to give the users the best experience?

Thank you all.