Double.indemnity.1944.bdremux.2160p.hdr.dvp8.se...

: The movie title and its original release year.

: This indicates it is a "remux" of a Blu-ray Disc. The video and audio data have been taken directly from the disc without being re-compressed, meaning it retains the original maximum quality of the physical media. 2160p : This is 4K resolution ( Double.Indemnity.1944.BDREMUX.2160p.HDR.DVP8.se...

In short, this is likely the (or a similar restoration) converted into a digital file format for the best possible home viewing experience. : The movie title and its original release year