The NDS side wasn't looking too bright either since the mini2sf format wasn't as workable. I even found a YouTube video that claimed foobar could output multitrack files, but I never found out how (because that would still be faster).
And now, even after being more-or-less familiar with Reaper, there still wasn't a fast enough way to rip each midi channel efficiently. And of course with no installs. My search led me to midicut, a program so old, even modern Windows won't run it. Combined with the light msdos.exe tool which allows midicut to run, I knew it was now possible to rip GBA/NDS multitracks by the batch load.
Keep reading to find out how!
Download all the tools here!
Inside the Tools folder, you'll find a version of VGMTrans where someone finally had the brilliant idea to add an export to midi and SF2 option instead of that DLS nonsense. The other 3 tools are links to the website so you can always have the latest version. You'll need Audacity to listen to the audio more efficiently at the end. Foobar will be necessary to convert the midis and I believe it has a portable install option. Get GBA Mus if you haven't already. I hear the January 2014 version is even better than the old one.
Ripping GBARipping music from the GBA has never been easier! Just open gba_mus_riper.exe (that's with the typo) in Command Prompt. Type out the name of the executable, then drag and drop the GBA rom you want to rip from. Hit enter and it should perform all its work. Some games may requires the -sb option to rip to a separate sound bank, but not many require this.
It should have made a folder by the same name as the rom. Inside, there should be a bunch of midi files and a SF2 file. Copy all of this and paste it into the input folder provided in my download. Finally, run InputSplitter.bat. The midicut program isn't very fast, but it's still much faster than doing this manually. It's best to just let it split music and not sound effects.
When the operation finishes, check the output folder. It should be full of folders now. Make sure there are 16 midi files named by number inside. The next step is the best part. When you're in the output folder, do a search for .mid. All the midis you just made should come up. Drag and drop all of the midis with numbers in them into Foobar. Right-click on them and go to Convert > ...
In the Converter Setup window, click on Destination. Next, set Output Path to Source Track Folder. Choose an output format of preference too. FLAC will sound the best and compress better than WAV, but something like OGG or MP3 is fine too. Save this configuration so you can use it later. Finally, run the converter. It should be processing all the midis at about 500x speed. Now, check your output folders and if it worked correctly, there should be audio files! (usually less than 16)
You can select all the output audio files and open them in Audacity. Playing them all back at once is how the music should sound like, but you can mute or solo certain audio channels you imported. Now that's kind of cool
Ripping NDSFortunately, NDS is a similar procedure. Using the included VGMTrans, you can drag-and-drop into it either an SDAT file, or the NDS rom directly. It should load all the music and list it across the bottom. Unfortunately, there doesn't seem to be a way to batch export everything to midi and SF2. You'll just have to right-click each of the items and export them one by one.
Take all of the files it exported and drop them into the input folder. You should have a folder full of midi and SF2 files all named the same thing. Run MakeTrees.bat and let it prepare those files in the tree folder for you.
After that, run TreeSplitter.bat to let it split all your midi files inside. This is just like the GBA part now. Run a search for .mid and drag all the numbered .mid files into Foobar. Convert all the selected files and you should have audio files for every track it extracted!
Check out some samples I converted.
I hope this works for others. It worked really efficiently for me and I've enjoyed it.