Video lags behind audio

[pph221]

Hi everyone,

I'm receiving complaints that participants see a time lag between the video and audio stream. Contrary to most situations I read about, this time the video lags behind the audio. The video input is connected to my laptop (connected wired to the LAN) using HDMI and is fed by a Dahua DVR that in return gets its signal from a security cam that is configured in the Dahua DVR as an RTSP video stream (we tried analog but the quality that the security cam delivers over the coax cable is very poor). Both are connected wired to the LAN. The audio signal is connected via USB from an amplifier system that has multiple mics connected to a mixer. Anyways, long story short, the video and audio signals are out of sync. The audio (received over USB) runs ahead of the video stream received over RTSP and converted to HDMI. The mic audio signal reaches Zoom much faster than the video feed, which has to travel over IP.

My question is whether there's a way to force a delay on the audio signal for say 500ms to get the audio signal  in sync with the video signal.

Thanks in advance for your help or suggestions.

[pph221]

BTW: I'm using a Windows 10 laptop. I've seen some tutorials for the Mac using Loopback and Audio Hi-jack, but obviously those don't work for me.