This is the "magic" part of the string. x265 is a video compression standard (High Efficiency Video Coding) that allows for high-quality video at much smaller file sizes than the older x264 standard.
(1999). This specific format——indicates a high-efficiency video encode designed to provide excellent visual quality at a smaller file size, typically including English subtitles. Technical Overview: The x265 Format eyeswideshut19991080pblurayx265esubkatm
To develop an article based on your specific request—likely referring to Stanley Kubrick's 1999 masterpiece Eyes Wide Shut This is the "magic" part of the string