General overview of modern encrypted FMOD bank/fbs files

BANK.bt

//===================
// DEFINITIONS
//===================
typedef struct 
{
    char MAGIC[4];
    uint32 FullSize;
    char FMTMAGIC[8];
    uint32 Unk1;
    uint32 Unk2;
    uint32 Unk3;
} RIFF <optimize=false>;

typedef struct
{
    char MAGIC[4];
    uint32 Size;
    byte Blob[Size];
} LSTCHUNK <optimize=false>;

typedef struct
{
    char MAGIC[4];
    uint32 Size;
    byte Blob[Size - Skip0Bytes(FTell())];
} SNDCHUNK <optimize=false>;

//===================
// HELPERS
//===================

void EnsureFormat(RIFF &header) {
    local string error = "Not a valid/supported BANK file";

    Assert(header.MAGIC == "RIFF", error);
    Assert(header.FullSize + 8 == FileSize(), error);
    Assert(header.FMTMAGIC == "FEV FMT ", error);

}

int Skip0Bytes(uint64 pos) {

    local ubyte b = 0;
    local int c = 0;
    while (b == 0)
        b = ReadUByte(++c + pos);
    FSeek(pos+c);
    return c;

}


//===================
// PARSING
//===================

struct BANK
{
    RIFF header;
    EnsureFormat(header);
    LSTCHUNK LIST0;
    if (FileSize() - FTell() > 8)
        SNDCHUNK SND;
} BankData <optimize=false>;