MPV has no menus for DVD, but it works very well. To start the DVD, access the DVD folders and drag&drop the VIDEO_TS
folder onto the MPV's window. Then do the same with the subtitle file.

From my experience, in this case the main movie is started directly.
To do that with a command, use something like
mpv dvd://
or
mpv /media/username/*/VIDEO_TS
To get the correct path for that, mount the DVD, copy/paste the VIDEO_TS path and replace the variable DVD movie name with *
, as indicated under this question.
That command can be used in a panel launcher, .desktop
file or shortcut to start playing the DVD with one click.
An example of .desktop
launcher:
[Desktop Entry]
Actions=Help;Bindings;Scripts;About
Categories=AudioVideo;Audio;Video;Player;TV;
Exec=mpv /media/username/*/VIDEO_TS
Icon=/home/cip/MY/ico/mpv_dvd.png
MimeType=video/x-theora+ogg;video/x-theora+ogg;video/x-ogm+ogg;video/x-msvideo;video/x-msvideo;video/x-msvideo;video/x-ms-wmv;video/x-ms-asf;video/x-matroska;video/x-flv;video/x-flv;video/x-flic;video/webm;video/vnd.rn-realvideo;video/quicktime;video/ogg;video/mpeg;video/mpeg;video/mpeg;video/mp4;video/mp2t;audio/x-wavpack;audio/x-wav;audio/x-wav;audio/x-vorbis+ogg;audio/x-tta;audio/x-scpls;audio/x-musepack;audio/x-ms-wma;audio/x-ms-asx;audio/x-mpegurl;audio/x-ape;audio/vnd.rn-realaudio;audio/vnd.rn-realaudio;audio/mpeg;audio/mpeg;audio/mpeg;audio/mpeg;audio/mp4;audio/mp4;audio/mp2;audio/mp2;audio/flac;audio/flac;audio/AMR;audio/ac3;audio/aac;application/vnd.rn-realmedia;application/smil;application/sdp;application/ogg;application/ogg;
Name[en_US]=Play DVD in mpv Media Player
Name=Play DVD in mpv Media Player
StartupNotify=true
Terminal=false
Type=Application
Replace username
with yours and the icon path. You can use this icon :)

or this

When the player is started with the command mpv /dev/sr0
, it will play and seek through all included streams including menus as if in a single file (no DVD menu support).
SMPlayer

Does the job of adding external subtitles to DVDs. No DVD menus by default, although this can be enabled as an experimental feature under Options -Preferences - Drives. (DVD menus seem to work if mplayer
is selected as multimedia engine but not with the more recent mpv
.) When the menus are not enabled the main movie is shown in playlist as one separate entry and is easy to identify and add a subtitle to it.
So, start playing the item that corresponds to the movie and then add the external subtitle: it should work very well.

External dvd subtitles usually look better than the ones on the dvd.
Exec=mpv /media/username/*/VIDEO_TS
– Feb 18 '16 at 17:30