The term "sourcefilmmaker" is a combination of two words: "source" and "filmmaker." In the context of porn videos, it likely refers to a filmmaker who creates content using material from other sources or with inspiration from existing works. This could involve remixing, editing, or re-imagining pre-existing footage, stills, or other visual elements.
In summary, a "sourcefilmmaker" is an adult content creator who takes inspiration and materials from various sources to create unique porn videos for the viewers.