Based on the string provided, this appears to be a filename or metadata for a repacked adult video (JAV) with the following details:
| Component | Possible meaning |
|-----------|------------------|
| jufe570 | Likely a catalog ID for a Japanese adult video (JAV) title (e.g., from the JUFE series by Fitch) |
| engsub | English subtitles (soft or hardcoded) |
| convert | File converted from one format/container to another |
| 015936 | Time offset in milliseconds (15 sec 936 ms), or a timestamp mark |
| min | Possibly “minutes,” or short for “minified” / “minimal” |
| repack | Scene release group term: a corrected version of a previously released file | jufe570engsub convert015936 min repack
Review:
ffmpeg -i jufe570engsub.mkv -ss 0 -to 00:15:36 -map 0 -c:v libx265 -crf 23 -preset medium -c:a copy -c:s copy -y jufe570engsub_trim_hevc.mkv