With this tool you can convert videos for 3DS.

Options

Source Video - Choose the video you want to convert
Video Folder - Folder to place converted video in (e.g. 3DS video folder)
Format - Type of 3D video, or 2D video
Quality - Quality (31 is lowest, 1 is max)
Advanced... - Show advanced options (replace Quality with Bitrate & FPS)
Bitrate - Bitrate of converted video
FPS - FPS of converted video

Changelog

-=v0.22=-
Fix splitting 3D video (thanks to Stylpe)
-=v0.21=-
Fixing (some of) the bugs of v0.2
-=v0.2=-
Added auto-splitting of files
Added "Advanced..." options
-=v0.15=-
Fixed bugs of v0.1
-=v0.1=-
Initial release

Download 3DS Video v0.1 BETA
Source- gbatemp