Does your directory look something like this?

If you do not have all the contents in the local folder (if at all), you must haven't installed Homebrew correctly, so I recommend you try to reinstall the process (guidance can be found in the docs), and then attempt to place the "ffmpeg" file in its correct path.
To further help you, I could contact you through skype or ts3, anything really to see if I could assist you further in any way, or you can just wait for CrushedPixel to come back with a response.