You will need to have them install mod_suexec (or make sure that it is installed). From there, they can add the following to your httpd.conf for your site:

SuexecUserGroup UserNameGoesHere UserGroupGoesHere

This way, whenever Apache calls the php binary, php will be executed as the use listed above and, thus, anything that is called by php will be run as the user above. This way, all of your videos will be created under your user and not the user that the Apache service is running under.