ROM Hack Extracting audio from .opp files?

[Sakuyal]

First, hello all. I'm glad to see these forums back up and running, and appreciate all that you guys do here at gbatemp.

As for my question, I've been trying to extract the voice clips out of Tokimeki Memorial: Girl's Side 1st Love Plus.
I'm 99% sure they're packed in a file called "voice.opp," since they're not in the .sdat file.
However, I've searched everywhere, and I can't even find any mention of .opp files in DS Games.
Does anyone here know of a way to extract the sound files from it? The programs I've seen that are normally used with audio, such as VGMTrans and Crystal Tile 2, don't work. It might be a custom format, but I have no idea where to start if so.

Forgive me if this is a simple question, but I have little experience in hacking/unpacking DS games.

Thanks!

 

[FAST6191]

Well I have never heard of the format before (and I do try to keep on top of such things- http://gbatemp.net/threads/the-various-audio-formats-of-the-ds.305167/ ).

Although there have been various tracker style audio formats before the size of the file and that you are looking for voices means these are more likely to be some form of (AD)PCM.

If that was not enough close to the start of the file
COPYRIGHT="2007 KONAMI DIGITAL ENTERTAINMENT"
artist="KONAMI DIGITAL ENTERTAINMENT"

As far as getting some pointers I have nothing from that file and the others in the directory do not look like they are pointers either (I had hoped ScheData.dat would be something, but there is not enough internal consistency to do anything useful).

I see a lot of KDEJ strings (possible magic stamps) which are usually (a quick scan says all except the first couple- audio files declaring a "track" to hold metadata is long established) followed by IFCL. That said there are a lot of standalone KDEJ stamps and often very close to each other (over 35000 by the time all is said and done and not all are 32 bit aligned).
KDEJ seems to be a possible header 22 decimal bytes long, I have not tried to make sense of it just yet though nothing pops out at me.

IFCL numbers 1671 according to a quick search. I extracted a handful from the start and what could have been the biggest one at just shy of 560 kilobytes (7BE64DE-7C71CAD)... I am truly awful at guessing/refining raw import values in audacity but I did hear something that sounded like music underneath the noise although with there being some 167 KDEJs between the limits there that might be way off.

Guess it is time to reverse engineer an audio format. I probably do not have time for it, but hopefully I have not wasted much time here.

 

[Sakuyal]

Thank you for the reply!

Unfortunately I can make little sense of what you've said, seeing as how I've never hacked/even unpacked a DS file in my life before yesterday and have no prior experience with anything else (when I said I had little experience, I meant little. Haha..)
However, it sounds like there is currently no way to reach these files without extensive work, and since I have no idea what to do (nor the time to learn right now), I suppose that's that.
You seem to know a lot about DS audio, though, and I really appreciate that you took the time to reply.
I'll keep what you've said handy in case I become more knowledgeable about this in the future.