Reducing resolution for blu ray 3d

I created an mpg4 file from a blue ray 2d movie, and opted to convert 2d to 3d side by side while doing it. I used the dvdnextcopy blu ray converter. The resolution was standard HD 1920 X 1080. When I try to play it back on toshiba 3d capable set using usb, I get message telling me that the TV doesn’t support 3840 X 1080. So my question is what’s the best way to approach this? Is there a way to reduce resolution down within the blu ray converter? Is the problem the fact that the TV reads both side by side screens, and is doubling up on resolution rates based on that? I’m also running the Anydvd in the background. thanks.