Natsume formats by Nisto at 7:20 PM EDT on June 12, 2020
I was recently asked to help someone ripping a couple of Natsume games, namely Omega Five (XBLA) and Gundam Battle Assault 2 (PS1). Had some spare time this week, so decided to look into these.
As there was evidently nothing out there to decompress the files in Gundam Battle Assault 2, I took it upon me to reverse the algorithm. QuickBMS has a supported compression type very similar to it (LZS_UNZIP), but there are some subtle differences which required me to write a separate tool. It can be found here: https://github.com/Nisto/lzsd
Subsequently I noticed that Omega Five also uses LZS compression/containers, so it's quite possible the Omega Five format is derived off the old PS1 format, but there's clearly some differences in the headers at least. Maybe with some small tweaks on lzsd, we could get it to decompress these too?
Getting back to Gundam Battle Assault 2, ripping proved to be further complicated because it uses a custom sequence format (DMF) and driver. I tried to find a compatible driver rip and stumbled across Hokuto no Ken, but unfortunately the format is once again a little different, so the driver is most likely incompatible with the formats from Gundam Battle Assault 2.
Anyway, maybe we could get a team effort going to rip these games?
Nice work, thanks. Just as a little bit of ancillary info, some if not all of the streams/XAs here were used in the previous game Gundam Battle Assault/Gundam: The Battle Master 2, and were composed by Nobuo Ito, incase that interests anybody.
Thanks for looking into these Natsume games, Nisto! While you're at it, can I ask if you can check out Gear Fighter Dendoh (also Natsume) for the PS1? If you want, I can provide you with the files if necessary. :)
@ChillyBilly Hey, man! I've been asking around on the general rip thread because I didn't see you around anymore. I've recently got hold of Pro Yakyuu Spirits 2013 and fortunately Nisto was able to help me come up with some .vas files from it, but I couldn't get a true complete and postable rip yet. I know you are very strong with the Jikkyou Powerful Pro Yakyuu series and you also help me once with Pro Yakyuu Spirits 2014 (which, if I'm not mistaken, was the one who raised your interest in the series), so I was really looking forward to talk to you about that.
Would you be interested in taking a look? If you have any other form of contact (Discord, etc), let me know :)
Driver is original and is the one Nisto used for Gundam Battle Assault 2. It's untimed, untitled and tags need completion for whoever wish to take care of it.
@Squaresoft74: Ooh, thanks for the Gaoranger rip! That's another set I've been looking forward to for a long time. :)
@rcsb: Sorry, I missed your post from the other thread! Yes, while I would indeed be interested in doing more Power Pro/Yakyuu Spirits rips, I'm still having trouble downloading big files at the moment, as I've mentioned in the Switch thread. I'll let you know when I'm ready to tackle them, though!
@ChillyBilly: I wrote a decompressor for Gear Fighter Dendoh, but I'm not sure if it'll help, since Squaresoft74's driver rip seems to expect PAC files containing LZS files, and both the PAC and LZS formats from Gear Fighter Dendoh differ from those of Hyakujuu Sentai GaoRanger. But maybe it wouldn't be all that time consuming to patch it to take uncompressed data?
EDIT: Looks like the DMF sequences from Gear Fighter Dendoh should be compatible with the Hyakujuu Sentai GaoRanger driver. At least I got 1 of 3 PSFs to play so far.
It might take a little bit to put everything together because the files in GFD basically have no directly identifiable headers, and I'm having to unpack and decompress everything, then repack everything to be compatible with HSGR. >_<