It would be cool to get this music finally in decent quality.
If you look for some people able to answer at some of your questions, maybe go to xentax.com, but Drolpiraat already started a topic with a view to a find a solution for unpacking beta music files, and no success.
TT's beta/special edition 44kHz sample-rate MPEG-based codec decoded.
Droolie sad that these files are rather not 44kHz.
to get the APMs converted into a common ADPCM standard (no conversion, just making it compliant with compatible players like FFMPEG)
the MPX version definitely has a higher frequency range
I think that is a dead end. And when you have compared these two versions of R2 recordings from the game, it fits into the puzzle that decoder shouldn't be responsible so much for deterioration of quality.
At least, achieved difference shouldn't be crucial. And I don't think it is even achievable to decode these files in other way. Or it would be hard eventually.
I'd be willing to set up a retro built PC with an SPDIF output equipped card for another run at it the old fashioned way.
I was thinking about that since you started to speaking out on quality of the rip.
I have tried to remaster it. And I noticed downsides of this particular compression and overall quality, which somehow could remind remastering PC files of Rayman 2. So results wasn't enough reassuring to draw my kind of special attention to finish the job. But it not means it is impossible.
And recently I was thinking about, if Special Edition may be better source for remastering, or just for listening, it may be good solution to capture music on fly. But while I was working more seriously on R2 files, it turned out that line-in rip files, though sounded better than converted files directly from the game, are worse to remastering.
If you have an opportunity to capture music via SPDIF digitally round-trip, so without analog distortions, it can be even better source to listen than we have know, and also possibly, for remastering. And I afraid it will be faster than looking for some people from all over the world to unpack this Special Edition music, or much less, decode PC files in other way with the aim of achieving better quality. Because finding such people may be difficult.
And I'm taken-aback that somebody noticed some depending on decoder in the game, and differences to unpacked/converted files from the game. Even if differences are not worth to canvassing, or even possible to repairing somehow.
It reminds me that I tried to push that argument before xd