I suggest you try this:
Re: Audio issues with MKV file on iPad Air
Postby anjunatl » Thu May 08, 2014 6:27 pm
Tried this and it worked. I have an iPad mini and was trying to watch an 1.56GB h264 720p video with AC3 audio. Changing the timezone from EDT to Zurich/Switzerland worked for me. I tried Central, Mountain, and Pacific with no luck - then tried something ahead of EDT - Atlantic Daylight Time / Halifax, CA. That worked. Seems like audio works when the device's timezone is set to any timezone ahead of the user's timezone but not when it's set behind it. Bizarre.
Any idea why audio playback is related to timezones? Doesn't seem to be a DST issue as messages started in the winter.
Even more bizarre, I left the video running while I went to Settings to change my TZ back to EDT. Went back to VLC and the video continued to play with audio. Paused and resumed, now in my current timezone, and no audio.