Getting a perfect sync in Edit Mode every time

Hello everyone! I've been lurking for a few weeks on this forum and I decided to share my knowledge of music and music editing programs to get a perfect sync in edit mode when you play. I did not see any guide using this method, so if this method has been posted before I apologize!

Now on to the guide:

Requirements:
-A computer (the program in this guide is for both PC and Mac users)
-Knowledge of some music theory (know what a measure/bar is)
-A song that you have trouble syncing in Project DIVA
-Usually about 10 minutes (will take longer if your song has a lot of tempo changes)

Whenever I go into Edit Mode I always tend to choose MP3s that have a teensy bit of silence at the beginning making it very difficult to get a nice sync with the song. However, using a Digital Audio Workstation (DAW) it is very simple to obtain a near-perfect sync. As a bonus, this method also works for songs that have changing tempos or songs that have non-constant tempos (like songs made by rock bands from the 00s and previous, before fixed tempos starting becoming popular).

The DAW that I personally use is called REAPER and can be obtained here: http://reaper.fm/download-old.php

I linked to the "Old Downloads" section because any version before 4.30 has an unlimited trial should you want to use this for obtaining a tempo map longer than 60 days.

Of course any DAW can work, as long as you can visually see the audio (called a waveform) and manipulate a tempo map at the same time, I just use REAPER since I own it and it's very simple to use.

When you open REAPER, you'll be greeted with a screen like this:

It will look a little different since I am using a different theme. If you want it to look the same as my screen, go to Options->Themes->Default_3.0

Next, import your song into the DAW (with Reaper you can just drag it into the window) and make sure to align the beginning of the song with 1.1.00:

If you're not sure whether or not it is lined up to 1.1.00, right click the waveform and go to Item Properties, at the top left the "Position" field should say 0:00.000 if the "Time" radio button is selected and 1.1.00 if the "Beats" is selected. If it is not, you can just type "0" or "1" (depending on the radio button selected) and press Enter, this will ensure the song is starting at 0.

I am using the song "I am the Best" by Korean Pop group 2NE1. I know the song's tempo is exactly 128BPM. So I go to Insert->Time Signature/tempo change marker, type in 128BPM (make sure the position says 1.1.00, if you haven't moved the red line in the program it should automatically say that). But when we look at the program after that, the song is off by about 175ms, or about 3 32nd notes (a dotted 16th note). For a rhythm game, this is a lot of desync (this is zoomed in):

Now to fix this, what we need to do is figure out where the start of the 2nd measure (or bar) is. In this picture, I circled it in red, and using the green circle is how we are going to fix it:

The green circle shows the tempo for the current project. What we are going to use it for is to line up the start of the 2nd measure of the project with the song's second measure. We achieve this by hovering over that number and using your mouse wheel to change the tempo of the first maeasure. For this song's case I need to set it to 117BPM (actually 117.2, but since I meant for this tutorial to work for both DIVA F and DIVA F 2nd I'm using whole tempos only, that .2 of a tempo won't matter too much. If you want to use decimal tempos for F 2nd hold shift while scrolling to change it by tenths of a BPM and Ctrl for hundredths):

Now the start of the 2nd measure of the project corresponds with the start of the 2nd measure of the song. All that is left now is to change the tempo at the start of the second measure to 128BPM and the song will be in perfect sync, we achieve this by placing the cursor on the start of measure 2, going to Insert->Time Signature/tempo change marker and adding a tempo marker for 128BPM at position 2.1.00.

If you were to go into Project DIVA F (2nd) and import the song, change the tempo of the first measure to 117 and the second to 128 you will get an edit that is in near perfect sync (at least a whole lot better than being 175ms off!). And if you want the game to display the correct tempo in the song list, just make sure to set the Tempo to 128 when you import the song. And then once you're in the actual editor change the tempo of the first measure to 117. This will make the song still show up as 128 in the song list.

Now to do this for songs with uneven tempos you might need a lot of tempo markers, as seen in this pic (all those Ts at the top are tempo change markers):

That song is clearly not something I would do in Project DIVA (that would take way too long), this was for another rhythm game I make custom content for, but it definitely would not be impossible to get such an uneven tempo song into DIVA using this method.

If you need to change a tempo quickly, all you would need to do is click on the waveform where you want the tempo change marker and then scroll your mouse wheel over the number I mentioned above, REAPER will create a tempo change marker at that spot for you. Continue this until you have tempo mapped the song.

Happy Editing!

 

I do what I can! I did just realize that I might have left some things out unintentionally. If anyone has questions about any steps of this method, please ask!

 

You can remove most of the silence I'd think. But then if you share the Edit Data everyone would need to trim their MP3 file. Which is kind of the opposite of what this guide is for.

I made this guide specifically so you shouldn't have to trim your files to get a better sync, with the added bonus that anyone you share the Edit Data with wouldn't need to either.