Foreword [Legendary N8]:
In the Groove 2 machines have been updated periodically, and as of 2006, you can choose a song, make steps for it, and play it on a machine. However, the only way you can do this is if you are playing on an ITG Machine that has been upgraded to R21 or later. When you go to play, check towards the bottom for the upgrade configuration - it should have R# (like R9, R21, R23). If you play on a machine that has been upgraded to R23, your songs MUST be under 2:30 in length. If they are not, the machine will not play them. If you are using the .ogg manipulation, the song will cut off after 2:30.
Part 1.1: Using Stepmania to make a simfile:
I assume you are at least familiar with Stepmania and its simfile editor program enough to at least START making a simfile. I am also assuming you are running a Windows operating system; if you have a Mac or other OS, you will need to change these directions accordingly.
In order to make a simfile, you will first need a music file (the song for your steps to go to), in either .mp3 or .ogg format. You will also need a .sm file (the file that holds the information for what steps show up). The best way to make a .sm file from scratch is to make a new .txt file (I'll call it "file.txt") in the folder with your song, and then opening it and use "save as" to save the file as "file.sm". Make sure you set the "save as type" scroll down menu to "All Files". Delete the text file if you want. You now have a song and a .sm file and can open up Stepmania.
Alternatively, an even easier way is to just "steal" a .sm file from another simfile you have. First, go to "\Program Files\Stepmania\Songs" on your computer (this may be different depending on the version of Stepmania you have and the operating system you are running). This is where all the songs in your Stepmania are located. This is also where you will need to put your own file if you want it to show up in Stepmania and be available to play.
Anyway, navigate to a song you like (or don't, it doesn't matter). Copy the .sm file located in its folder and paste it in your own song's folder (a folder that contains your .mp3 or .ogg file). Open up the .sm and delete everything below the sectionwhere everything starts with a "#" (or just delete evrything below "#BGCHANGES:;" or "#KEYSOUNDS:;"). Be sure to delete the stuff between the colon (:) and semicolon (;) in the #TITLE, #ARTIST, #OFFSET and #BPM sections too (and #STOPS if there's anything there). Fill in #TITLE and #ARTIST with your own song's info, but leave the rest blank for now.
Part 1.2: Syncing your simfile (at least passably well):
Now, I've always had a harder time syncing simfiles than making them. This section will be short, and I hope you will look elsewhere for even better advice. The short method I have listed here should get you at most .01 seconds off-sync, which most people can't pick up (although some very good players can tell if a file is even 1/100th of a second off).
There are two key parts to the sync of a file: the BPM (tempo) and the GAP (offset). The GAP should always be the first thing you try to find with your sync.
Before you sync, I recommend you slow the music down. This makes it much easier to tell, visually, if the file is early or late. To slow the music down, go into the "song options" on the menu opened by pressing escape and scroll down to the "song rate" option and set it to somewhere around .5x and .7x or so. This makes the music play slower.
To find the GAP, place an arrow on the first note of the first measure of the song. You are trying to line up the first beat of the music with the first arrow. If the first beat of the music is before the first arrow, the file is "late" and you can hit F12 to move the chart .02 seconds earlier. Conversely, if you find the first beat of the music is after the first arrow, the file is "early" and you hit F11 to make the file .02 second later.
Once the GAP is correct, you need to find the BPM. Assuming your song has a constant BPM (if you're thinking of making a file to a variable BPM song, you shouldn't need this guide, or you should really rethink stepping that song!), you can use a music analyzer to find the BPM, or if you insist on doing it manually, place quarter notes on every beat of the song, and play your file with your best guess for the BPM. If you notice the notes are getting early as the song goes on, your BPM is too fast and you can hit F7 to slow the song down. Likewise, if you find the notes are getting late, the BPM is too slow and you hit F8 to speed it up. Do this until the notes match up.
Alternatively, there is a somewhat easier way. Rather than finding the GAP first, you can find the BPM first too. How do you do that? Go here and download Mixmeister BPM Analyzer:
Trust me, it's worth the 10 seconds of your life that it will take to fill out the small form and download it. Once you've got it, open it up and drag and drop your .mp3 onto it (it doesn't understand .ogg files - see below for how to convert your .ogg to an .mp3 if you only have an .ogg). After a few seconds, it will give you the BPM for your song. This program is by no means flawless, but it is right more often than not. If your song has a decent and steady bass beat, then chances are it's correct. If nothing comes up or later you find out it's not the right BPM (and this is your first file), then find a new song. Ask for help in the forums here if you can't find a song that gives a steady BPM, we can help.
Now go back to your .sm and input the BPM that Mixmeister gave you between the colon (:) and semicolon (;) in the #BPM part. Now you're ready to open up your song in Stepmania's editor. Open Stepmania, go to Edit Mode, navigate to your song, and open it up. Now you need to find the GAP. One good way to do this is to just put a bunch of quarter notes (red notes) or 8th notes (blue notes and red notes) that start on where you think the first beat of the song takes place, then keep playing that part over and over again, moving the group of notes up and down until they are on-sync.
Press 1, 2, 3 or 4 to input arrows. If you press left and right on the arrow keys, you can change the arrows you input from quarter notes all the way to 128th notes (in some Stepmanias). If you press space bar and then scroll down and press it again, you can highlight a section. Once you've highlighted it, press Enter and go to Cut. Scroll up or down a bit (depending on if your arrows feel early or late) and then paste them up or down a bit more than they were (I recommend going in increments of 64ths). Once your arrows feel like they match the music, scroll up to your first arrow and look to the right where it says "Current Second". Put that value into your .sm file between the colon (:) and semicolon (;) in #OFFSET (as a negative number, since you're actually "deleting" those seconds before the arrow comes up. Save your .sm, press ESC in Stepmania and go to "Reload from Disk", and now your simfile should be onsync. No need for 64th and 128ths anymore, the normal red and blue arrows should be okay. If they feel off, then repeat.
Even more alternatively, you can just create a bunch of arrows and keep pressing F7/F8 until they feel like they're more or less onsync. It won't be as fine-tuned as the above methods, but it works okay sometimes.
Either way, try to sync your file before you start making it.
Step 1.3: Make your simfile!
…wait, you want to know how to make a good file? … I'll be writing a LOT about this topic, two and a half whole parts, so… ya. Moving on…
Step 1.4: Set your simfile up for r21 Play
First of all, you need an .ogg file. If your song is .mp3, use a converter like Audacity (http://audacity.sourceforge.net/). Load your song into Audacity, select "Export as Ogg Vorbis" from the file menu, and export it. That wasn't so hard, was it? If your file is under 2:00, you're set to go. If not, you need to download the following patch:
Extract it and drag the .ogg file over the .exe file. There should be a brief flicker of the screen, and now Stepmania/ITG thinks your sound file is 1:45 long, even if it isn't! And that's pretty much it. You still have to place the file into the right folder of your USB drive, but there's a lot of explanation of how to do that (See the FAQ), so I'll move on to the fun part: making your files better.