Hi,
With emphasis on the fact we will not be able to provide official support should this malfunction, and also that you'll need to reapply whatever patches you make at each upgrade, the relevant code is here:
/opt/kaltura/app/infra/cdl/kdl/
For example: /opt/kaltura/app/infra/cdl/kdl/KDLOperatorFfmpeg1_1_1.php