This guide will cover how to resolve audio and video desync when using Facecam in OBS Studio. 

Set Facecam to 60 Frames Per Second

If Facecam is set to output 30 frame per second (fps) video, the frame rate is dynamic. Learn more about variable frame rate here. Unfortunately, OBS Studio does not play nicely with variable frame rate video and that can cause video to desynchronize from audio over time. Setting Facecam to output 60 frames per second video uses a constant frame rate and can help. 

1) Open OBS Studio.

2) Right-click on the Facecam source inside a scene.

3) Set the 'Resolution/FPS Type' to 'Custom'

4) Select the desired resolution.

5) Select either 60.00 or 59.94 frames per second.

6) Click on "OK" to close this window.

Disable Buffering 

Capture device sources in OBS Studio have an option to enable or disable buffering. This will buffer a small amount of video from the capture device to smooth out any jitter or tearing that might occur if the incoming frame rate is not consistent. Buffering can cause increased video latency and desync over time in certain cases. Disabling buffering for Facecam ensures lowest video latency. 

1) Open OBS Studio.

2) Right-click on the Facecam source inside a scene.

3) Find the 'Use Buffering' setting.

4) From the dropdown menu select 'Disable'.

5) Click on "OK" to close this window.