Yeah - “dummy_f.dat” is all blank.
Dug around on the DFEX folder that appears on some discs. Looks like it is a “Digitial” copy scheme called Vividy by a mob called “Secure Content Storage Association (SCSA) LLC” owned by Warner Bros, 20th Century Fox, Western Digital & SanDisk. The *.scav is the video, *.scaa is the audio(s), and *.ocmp is a Pic. Interestingly the companies website is down - www.vidity.com/ . It is worthless to us.