This player is horrible. For a side by side content i use pantarheon.org/AviSynth3DToolbox/ which is AviSynth plugin. Scripts look like this
lv = DirectShowSource("D:\\3d\\Grand.3DBD\\Grand.Canyon.3DBD.Left.1080p.DTS.x264-SWEMUX.mkv")
rv = DirectShowSource("D:\\3d\\Grand.3DBD\\Grand.Canyon.3DBD.Right.1080p.DTS.x264-SWEMUX.mkv")
and can be played in every directshow player (like MPC-HC).
If you want subtitles you need this...