Question about DVD resolution for Vero 4k +

How can I add resolutions for DVD? For example: 704 × 576 or 720 × 404 / 25Hz?

In settings for allowable resolutions can be set with me only up to 720p.

720x576@50Hz and 720x480@60Hz are standard modes. If your display supports them then they will be selectable in Kodi. If your GUI resolution is 1080p, you will have to whitelist the lower modes and set Adjust refresh rate to On start/stop.

Yes, I can select these resolutions.

But DVDs in 4: 3 format are not reproduced correctly. The picture is stretched.

What could be the reason?

Have you set Settings- > Player- > Videos- > “Display 4:3 videos as” to “Use HDMI AVI signalling”? If not, give that a try.