Uh, on SmileBASIC or the 3DS in general? If you are talking about SB then i don't think that there is any way to record video on it. As for audio, i think you can but i'm not sure how.
If you want to record video on SB, don't bother because the 3DS already has a built in camera made for you to take pictures and film with, so just use that.
0そうだね プレイ済み