time synhronisation of videos

[Julyy]

Hi,

I have 5 videos from 5 cameras of 10 hour recording each. Sometimes cameras were switched off during the process of filming (not synchronically). I want to find video intervals where all 5 cameras are recording and make a split screen (5 videos into 1 video screen, time synchronised correctly). Is there an easy way to do it? I wanted to use avisynth, but all other options are welcome.
Thanks.

[smrpix]

Use an NLE where you can put each camera on a different track, sync them up and then resize. Any version of Sony Vegas comes to mind. Premiere Pro or Edius will also work.

Trying to sync and calculate offsets in preparation for using Avisynth will be a long, frustrating endeavor.