What are these AV1, AV2 files?
 

My editor finally sent me back my project, 3 QT files, run about 10 minutes each. But below each of these are clips AV1 & AV2. I asked my editor what these are and says he sometimes gets them, but does not know why. That I should test playing without them.

I tested and the QT's wont play without them. They add 12GB that I now have to permantly archive on my hardrives. any tips appreciated.