I assume the mediainfo plugin is the one that gives you the info boxes with MKV, H.262, 3:2, Dolby Digital, and 5.1, etc? If not, I have no idea what to look for. In any case, all the movies that have no sound show DTS/DS. The rest of the movies that do play sound all show Dolby Digital even if I did rip the DTS soundtrack too.
I ripped everything with both DD and DTS soundtracks if available except the 6 movies in question, if that helps.
On a side note regarding GraphStudio, in trying to fix this problem, I inadvertently inserted the Microsoft DVT-DVD Audio Decoder filter instead of the LAV Audio Decoder but now I can't change it back. I also noticed that if you right click on the title file box, there is a Stream Selection option. It shows which are the default streams as well as the other video and audio streams. Selecting a different audio stream does absolutely nothing, however. The next time you bring it up it's right back where it was originally. In fact, I can find no way to make any change stick in GraphStudio except that first one I did and now I can't change it back.
That's everything I can think of that I did or has changed since I noticed this problem.
Originally Posted by assassin
Use the mediainfo program and try to see what is actually being encoded in the MKV.