For those of you who have a 3DS but haven't learned how to watch videos on your 3DS, it is possible but very limited.
First off, you cannot watch streamed movies over the internet. That means no YouTube or Veoh. Nintendo to date has refused to allow Flash on the 3DS. However, if you find a YouTube video that you like and want to be able to watch whenever and where-ever on your 3DS, that is possible and quite easy. This goes for 3D videos on YouTube, too. (Same holds for making 3D pictures on your computer to pass off to your friends.)
To convert YouTube videos for use on a 3DS, you first need to download the videos using a file conversion site or the "Download YouTube Videos As MP4 and FLV" extension for Firefox. Save the file as an AVI or FLV. You can save as MP4 format or WMV, but this will take a little more work to use. You can use your own videos too, but keep in mind that videos on the 3DS must be less than 10 minutes long, just like a normal YouTube video.
Now you will need to download a little app called
3DS Video. Run the program and choose the video you want to watch for the
Source File. Set the
Destination Folder to something simple, like C:\ or the 3DS's memory card (you cannot use spaces in the path name). Next you need to specify what kind of video file you are trying to convert. If the video already has both images in it, choose the proper orientation (side-by-side or top-bottom). If the video isn't a 3D video, choose
2D. If you are trying to convert a 3DS video to share (dunno what this option actually does), pick the 3DS one. You'll probably want to make sure
Keep Aspect Ratio is checked. Set the
Audio Bitrate, since a default of 96kbs is probably lower than the source file. The max bitrate can be 320kbs, but if your source file only has a bitrate of 106kbs, there's no point in raising it. (You can find the bitrate by using
MediaInfo.) Finally, click the Convert button.
If you converted a side-by-side video and the images are reversed, do it again with
Mirror Input Video checked.
The converted video will be named VID_0001.AVI. You will need to change this for the 3DS to recognize it. Open the 3DS's memory card and find the folder
DCIM\100NIN03. This is where video files and pictures are stored on the 3DS's memory card. (Sound files are stored in the
Nintendo 3DS\Private\00020500\voice folder, but you should put music in the
DCIM folder.) If you have taken any pictures or recorded any movies on the 3DS, you will see files called HNI_00XX.yyy, where XX is a number and yyy is the file extension. The 3DS itself makes three extensions: JPG, MPO, and AVI. JPG is a preview of a 3DS image (or the image itself if using the inner lens). MPO stores the stereo image information. AVI is movies. Find the highest value for XX and rename VID_0001.AVI one higher. So for example, if you have three files in your 3DS - HNI_0001.JPG, HNI_0001.MPO, and HNI_0002.AVI, you would rename VID_0001.AVI to HNI_0003.AVI. If you haven't done so already, drag-and-drop the new video file into the
100NIN03 folder and you're set!
As I said, if you have an MP4 or WMV, you will have to perform an extra step. Due to a bug in 3DS Video, MP4 files don't get converted correctly. So first you need to convert the MP4 to an AVI yourself. Open up the
RUN function (press the Windows logo key and R, or press CTRL+ALT+DEL and select "Run..." from the File menu) and type
cmd to load up the DOS interface. Set the directory to wherever 3DS Video is (type
cd PATH where
PATH is the full directory, such as C:\Documents and Setting\Local User\My Documents\Downloads\3DS Video v1.0) and then type
ffmpeg.exe -y -i inputfile.mp4 -r 30 -b:v 6000k outputfile.avi, replacing "inputfile.wmv" with the MP4 or WMV you want to convert, and replace "outputfile.avi" with whatever you want to call the converted file. Note: this is not a 3DS compatible AVI, but 3DS Video will be able to convert it into one.
If you want to make your own 3DS compatible still-frame pictures, the process is a little simpler. Simply download the program
Stereo Photo Maker. Run it. If the picture you want to convert for 3DS viewing already has both images in it, select
Open Stereo Image, otherwise select
Open Left/Right Images. If you have to pick the images separately, try to put
_l and
_r at the end of the file names, then hold CTRL while clicking on the files. Make any adjustments you may need and then under the File menu select
Save MPO. The same naming rule applies here as it did with video files - HNI_XXXX.MPO, where XXXX is an unused number. Save the file to the
100NIN03 folder on the 3DS's card and you're set.
I've tested each of these. Lots of forum reading. Some people don't have the stubbornness to keep reading. Lucky for you guys, I didn't give up. And right now Inccubus is probably wishing I'd say the same thing about my program instead of playing Fable: The Lost Chapters.
Edit: I'll upload proof this works when I get home next year.