I'm able to play some .mkv files with no audio sync issues. I do however have one .mkv file that has audio sync'ing issues. I have ffdshow tryout installed and Haal spliter running on Vista. I have ffdshow audio set to spdif? I heard that .mkv files can contain various audio files so maybe I dont have that codec installed? I thought ffdshow had pretty much everything. Is there a way to figure out what audio file is in the .mkv file so that I can watch the movie without the audio ahead of the video by about 3 seconds. Sorry for all the questions just learning about x264 format.