Leawo Blu-ray Ripper for Mac has a built-in 2D to 3D converter that would allow you to add 3D effects on ordinary 2D videos and convert the 2D video into a 3D movie.
To get to the 3D effect panel, click on the Edit button on the target video file and then click the 3D button on the left side.
On the 3D panel, click on the 3D Mode button to apply 3D effects on the video. There are 6 different 3D effects provided. Choose one 3D effect and preview the effect on the preview window on the top area. You can also adjust the 3D depth by adjusting the dot on the 3D depth bar or entering a value in the box next to the bar.