PS VITA .bnk files

Extraction and unpacking of game archives and compression, encryption, obfuscation, decoding of unknown files
C4K
Posts: 1
Joined: Sat Jul 21, 2018 9:50 am

PS VITA .bnk files

Post by C4K »

I've extracted from PlayStation All-Stars Battle Royale (which I'll refer to as PSASBR from now) the game assets and started looking first at the sound/music files. The game uses two kind of files: .csnd (single file audio) files and .bnk (audio archive). The game is organised as each character of the roster got two .bnk files, one for FX and one for VO. Then, there are various .csnd files stored elsewhere which are supposed to be used in the audio stream. Thing is not all .csnd files are actually used. E.g. characters' VO are used in .bnk files, despite there are all the .csnd that the game could use for that. Infact, if you delete such .csnd files, nothing will change, VO will still work. EXCEPT for one character, Dante, which I'll explain better later.

As first thing I wanted to try extracting these .bnk files, but as soon as I got them I had no idea of what I had in front of me. These do not look like Wwise bnk files at all, I've searched through the Internet and found pretty much nothing about them. To be sure that the format wasn't misleading me (I've taken some to figure out what .csnd were) I've found another game using .bnk files, Pix The Cat. Even there, the format was the same as PSASBR, so I was still clueless. Searching on the internet even more, I've found a guy asking help for a Sly Copper .bnk file extracted from the PS2 game. Taken a look into it and, even if not the same, it's very similar to the ones used in the PS VITA games I've talked about. However, that guy didn't get any help, so still clueless here.

All the .bnk files have this magic SBlk (not at the beginning) and then just raw data (in the case of PS VITA .bnk files, at some point there are strings that should be the names of the audio contained in it). Being very similar to the Sly Copper PS2 .bnk file, I could think that the PS VITA .bnk files may contain VAG audio. However keep in mind that PS VITA can stream AT9 audio as well.
Here an archive containing all the .bnk files I've talked about. Any help is appreciated :D . I wanted to at least rip the audio and then eventually repack it back to the original format for modding, but maybe it's more difficult than expected. However I think there is something with Dante's VO bnk file. This is just conjecture so what I'll go to say ahead may be something really stupid.

As I mentioned before, Dante's the only one that uses the .csnd audios in the game assets regarding VO. Let's say that you get all these files and delete them: the result will be in Dante getting muted, while all the other characters will still be able to talk. That of course would make think that Dante for somewhat reason is the only one using the .csnd files, while all the others are relying on the .bnk ones. Infact, if you delete the .bnk files from the other characters, they'll get muted as well. However, even if like this it's been proved Dante uses the external .csnd files, if you delete his VO .bnk file and keep the .csnd files, he'll still get muted. With this evidence the only conclusion I can come up with is that his .bnk is "set" to load files externally. This is just conjecture but I really can't explain it in another way. That's why I've included in the archive both Dante's bnk which VO is affected either deleting these .csnd files OR the .bnk file, and PaRappa, which just like all the rest, his VO is affected deleting the .bnk and not affected when deleting the .csnd. It wouldn't be bad to get what's the deal behind this if it is within these files, since if the .bnk could really be "set" to load the files externally modding the audio would be much easier.