MUZAK authoring?

Hello, well after doing some reading on the forum for a while I realize this issue was touched on at one point, however I don’t think it answered what I am looking for. At work I have a standalone (not connected via ethernet or sat.) Muzak system which pulls music off of specified DVD discs and stores them on an internal hard drive as a playlist. I have been trying to figure out the format on these DVDs for a while so we can make our own disc and add a few songs of our own at the store. I have read about the old CD-I ripping software, etc. However, as these are on the DVD discs I don’t believe that format applies any longer. Does anyone have any insight into if and how this can be accomplished??

Who makes the hardware?