1-2 seconds? Hardly - Humans start noticing at about a tenth of a second in lag, and it's unusable at beyond a half second. When you're videoconferencing, all of your latency is eaten by the speed of light - You've got no time for buffering, you've barely got time for pre- and post-processing.
When doing a live video conference, you can only have about a 1 to 2 second buffer before the connection becomes unusably laggy.