VLC conversion rotates exported video 90 degrees

[tinacart]

Hello:

I have VLC Player for Windows 2.2.1. I'm running Windows 10 home edition 64-bit.

I'm trying to convert MKV files to MP4, but when I do so using the VLC's conversion tool, the output plays back rotated 90 degrees on any video player I use (suggesting that it was encoded this way).

As a test, I'm using the first MKV sample video available in the list at http://www.sample-videos.com/.

I used the default VLC settings thusly:

1. I clicked Media > Convert / Save > Add (my video) then clicked "convert /save. "
2. I chose the MKV file as the source then chose "Video for MPEG4 1080p TV/device" in the drop down.
3. Using the configuration icon, I verified that there are no filters being used on either the audio or video settings.
4. I chose my destination file with an .MP4 extension, and then clicked "Start."

The software performs the conversion, but when I open the outputted MP4, it is rotated 90 degrees clockwise. This is the natural output of the video. I've tried playing back the MP4 in all available software: Windows Media Player, QuickTime, VLC and the DIVX player --they all play it rotated 90 degrees. The MKV source is NOT rotated 90 degrees when it's played back.

What am I doing wrong?