Does there exist a software which will convert the video content of a DVD to MP4 ? It would be necessary that language and subtitles can be selected.
An easy, although time consuming, way is to do it in two steps.
Make MKV will rip the DVD to an MKV file, which contains the subtitles and language elements.
Handbrake can then be used to create an MP4 from the MKV using the elements that you desire.
It is time consuming as each stage will take a while to execute. However, it has worked every time I have used it.
I've always had good results with DVD Decrypter and Handbrake or ffmpeg (which is command-line only and is what Handbrake uses). I like this solution because I keep the decrypted DVD format for future transcoding and so I can watch it in it's original form with menus intact on a PC, and so I can transcode for different devices in the future.
You can use Format Factory to achieve this directly in one step.
It support a lot of video formats to directly convert them to MP4 format.