I remember when EBA came out there was some songs where the cover was actually a bit better than the original and I remember trying to use the sseqrip/strm2wav tools from http://loveemu.yh.land.to/ to extract the songs. Now, I tried to do the same with Ouendan 2. Unfortunately, I forgot how I did it with EBA so it's not surprising that I'm having problems trying to extract the sound files so I can convert them. If it's like EBA, I'm guessing Ouendan 2 uses STRM but how do i extract that?