How to convert a 3D-video to Nintendo 3DS video-format

With the firmware update for Nintendo 3DS in early December 2011, the handheld from Nintendo was made able to record and playback 3D video.

I have an Aiptek 3D i2 camera, and have already recorded some videos in 3D. Now I can convert them to be watchable on the Nintendo 3DS, check out these videos. If you haven’t got a 3D-video, YouTube is full of them.

How to convert?

The easiest way to convert a video to the Nintendo 3DS videoformat, is to head over to socoder.net and download 3DSMovie.

It’s straightforward. You don’t have to change anything. Choose the video you want to convert and where to save the converted video, and then press Convert.

Copy the converted video to one of the folders in the DCIM-folder on you Nintendo 3DS’ memory card. Or better, make you own folder for your converted videos. The folder have to be named AAABBBB, where AAA is a number 0-9 and BBBB is a letter A-Z.

The hard way

You can also convert a 3D-video the hard way. Download ffmpeg open a DOS-shell and type in the following (assuming you have called your video ‘video.avi‘):

ffmpeg -y -i “video.avi” -s 800×240 -aspect 2:1 -r 20 -vcodec mjpeg -qscale 1 -vf crop=400:240:0:0 -acodec libmp3lame -ar 44100 -ab 96k -ac 2 “left.avi”
ffmpeg -y -i “video.avi” -s 800×240 -aspect 2:1 -r 20 -vcodec mjpeg -qscale 1 -vf crop=400:240:400:0 -an “right.avi”
ffmpeg -y -i “left.avi” -i “right.avi” -vcodec copy -acodec adpcm_ima_wav -ac 2 -vcodec copy -map 0:0 -map 0:1 -map 1:0 “VID_0001.AVI”

Some explanation. Nintendo 3DS records 3D-video at 20 frames per second. But I have successfully converted with both 25 and 29.97 fps and the 3DS will play that too. So the -r 20 in the instructions above can be changed to 23.97, 24, 25, 29.97 to better match the framerate on the original video.

-ab 96k is the audio-bitrate. I’ve been using -ab 128k to get some better audio quality.

-qscale 1 is the video quality. 1 is best, 31 is worst. If you need to have a smaller filesize of the final video, you can change this number. I will probably recommand using between 1-5. See socoder.net for more.