How to play bluray in vlc 2.1.0

[smartloper]

hello everyone, I used libvlc in a C# project to play bd discs, there has some problems,

for the latest version 2.2.1, i can play bluray file correct, use libvlc_media_player_play method for MRL "bluray:///H:/", but when dragged the timeline, i must wait more than 10 seconds, it is very worth ;

then i changed to use version 2.1.0, in this version ,when drag the timeline , i just wait 1 or 2 seconds ,it's ok; but I can't use MRL "bluray:///H:/" to play the movie.

then i find the lagest .m2ts file under H:/BDMV/STREAM/ and play that file, it works because most discs contains just a file over 20G for a whole movie , but a few disc, there have more than one .m2ts ,then i don't know which .m2ts files to play and in which order to play these files,

i can't player H:/BDMV/index.bdmv file in libvlc, there is very few information about the structure of index.bdmv, can anyone help me to solve this problem: to read the correct playlist for a movie in bd discs or to use MRL "bluray:///H:/" in version 2.1.0, the version greater than version 2.1.3 can't give good support for dragment, also in vlc.exe