In most cases, audio and video arrive from input sources more or less simultaneously. However some video sources my have latency introduced by a slow encoder, causing audio and video that aren’t synced up. (One example of this would be video arriving from an encoder such as an Elgato Cam Link 4K, with audio arriving from a different source such as a USB microphone.)
In this case, you may wish to add a slight delay to your audio input. To do this, adjust the Mic Delay slider in the Audio section of Ecamm Live's Preferences.
Note that you will not see the mic delay adjustment in real time. You'll only see the results of the adjustments when watching a live stream or playing back a recording. We recommend using Ecamm Live's Record Only mode to make some test recordings to determine the appropriate audio delay for your situation. For example, in our testing, the Cam Link 4K required a 6 frame delay.
Also, don’t forget to put it back when a delay is no longer needed.