• First, copy the DVD to a hard drive

• Use VLC to check which are the correct files. In the example below, they are VTS_01_1.VOB to VTS_01_3.VOB.

• Define a few variables

dvd_folder=Desktop/MetaMecano-VIDEO_TS
out=Desktop/MetaMecano-DVD.mkv

* send to ffmpeg for rewrapping or transcoding

time cat "$dvd_folder"/VTS_01_[123].VOB \
| ffmpeg -r 25 -fflags +genpts -analyzeduration 1G -probesize 1G -i - \
  -map 0:v -map 0:a -map 0:s -c copy -r 25 \
  "$out"

To copy all subtitles, use

-map 0:v -map 0:a -map 0:s -c copy

Using just

-map 0 -c copy

doesn't work because of

Stream #0:0[0x1bf]: Data: dvd_nav_packet :
  [matroska @ 0x7f7f6e875400] Only audio, video, and subtitles are supported for Matroska.
  Could not write header for output file #0 (incorrect codec parameters ?): Invalid argument)

Or to copy only the first subtitle track, use :

-c:v copy -c:a copy -c:s copy