ONLY use DGIndex from Donald Graft's dgmpgdec suite. Alternatives like d2vwitch may sound enticing but it's simply not as efficient nor time-tested as DGIndex, even for Linux users (perfect support via Wine).
You can find it here: http://rationalqm.us/dgmpgdec/dgmpgdec.html with v1.5.8 being the latest final version. Source code compilable on Windows using VS2019 is also available and I have to thank Donald Graft for helping me with getting it repackaged from VS 2008 to VS 2019 as it had a fuck ton of breaking changes in terms of compiling on modern machines because of it, which he helped out with since he understood his code base best.