I have the dub for an anime as a separate audio file, but unfortunately, said dub skipped the opening, and therefore I cannot use it as is with my previously-downloaded raw. I tried using the audio delay option, giving it a -90000ms (1:30min, the length the opening) delay, so that the audio will be synchronized, but the results have been all over the place. Sometimes the video freezes and sometimes it skips 90 seconds ahead as expected. Now, even when it does succeed, I lose the ability to move along the video. If I try to move, then it'll stay silent for 90 seconds, and after that the audio will start, only a further 90seconds ahead.