"that copyright is not automatically conferred and that there is a process that must be followed"
No, this is completely backwards. Copyright is automatic (in most places), but there is a formal process if you want. Copyright happens the moment that the work is created. In the US, if you want to sue somebody for copyright infringement, you have to register your copyright, but you still have one regardless of registration.
Modifying the video is a derivative work and must be licensed/released from the original author/copyright holder.
When is my work protected?
Your work is under copyright protection the moment it is created and fixed in a tangible form that it is perceptible either directly or with the aid of a machine or device.
Do I have to register with your office to be protected?
No. In general, registration is voluntary. Copyright exists from the moment the work is created. You will have to register, however, if you wish to bring a lawsuit for infringement of a U.S. work. See Circular 1, Copyright Basics, section “Copyright Registration.”