Gravity Games Bike (PS2) *.BNK

[Game Ripper]

Hi guys, may I ask for help with unpacking these banks? There might be a table with headers for contained streams (0x44ac & 0x803f are frequent in file start, can it stand for frequency & interleave values?).
As for an outside TOC for those banks I don't really know: most game assets (apart from videos + bigger part of audio) seem to be packed in yet another (proprietary?) type of bigfile, BIGOFILE.DAT & its size is almost 1 gigabyte! Well there're 3 much smaller DAT files too.

All samples are here: BANK0000.BNK comes from MUSIC folder & the remainder of *.BNK samples was found in SFX folder (I included the latter for comparison reasons).
Thanks in advance fellow rippers! Bye!

[aluigi]

The format is a mess but there is definitely some playstation adpcm data there.

[Game Ripper]

Well thanks for looking into it, I appreciate it but maybe we should stop there since ripping PS2 version is hardly worth the effort: Xbox port uses easily accessible streams plus audio quality is supposedly way higher there anyway (WMA vs. ADPCM).
I was hoping that PS2 wouldn't give us so much trouble because I ripped it many years ago, it turned out to be wrong but it's not like I really want to make another awkward halfway-decent rip using Cube media player or ADPCM Player or MFaudio...

Bye and thanks again!