Actually, it was never mentioned once that the movies were under copyright or not, so some people seem to be WAY off topic. The question was whether DTS can properly be copied from one DVD to another - no mention of how to break copyright encryption, or performing any illegal activity was, or should be, discussed.
If you are (legally of course) copying a DVD then DVD Shrink, which can be Googled for, is an excellent way to easily make a 1 for 1 copy, or a compressed copy of any movies you own. It allows you to choose which titles, soundtracks, extra features, etc. that you want to copy and onto which size disc you would like to put them onto.
If you drop your DVD into your PC and tell it to make a FULL copy onto a single layer DVD, then it will rip the DVD to your hard drive, then recompress the video to fit on the disc and include all full audio formats in the copy including DD and DTS if they are on the original disc. As a bonus, if you are using Nero CD/DVD recording software, it integrates seamlessly with it and will automatically start burning the disc for you.
I use two DVD drives in my PC which allows for nearly one touch backups to be made as necessary.
