for WarioWare: Get It Together!, Python 2, no warranty if it breaks on some file

extract_wmbt.py

from struct import unpack
import sys

def align(value):
    return value + (0x10 - (value % 0x10))

def full(f):
    return unpack("<I", f.read(4))[0]

def LBL1(f):
    start = f.tell()
    count = full(f)
    table = []
    for i in range(count):
        table.append(unpack("<2I", f.read(8)))
    assert table == sorted(table, key=lambda x: x[1]) #can read strings in-place
    returnme = []
    for entry in table:
        f.seek(start + entry[1])
        addme = []
        for i in range(entry[0]):
            size = ord(f.read(1))
            string = f.read(size)
            index = full(f)
            addme.append([string, index])
        returnme.append(addme)
    return returnme

def TXTW(f, fullsize):
    start = f.tell()
    count = full(f)
    table = []
    for i in range(count):
        table.append(full(f))
    table.append(fullsize) #so we don't get an off-by-one

    returnme = []
    for i in range(count):
        f.seek(start + table[i])
        string = f.read(table[i+1] - table[i] - 2) #null byte terminator
        returnme.append(string)
    return returnme

with open(sys.argv[1], "rb") as f:
    with open(".".join(sys.argv[1].split(".")[:-1]) + ".txt", "wb") as o:
        header = unpack("<8sH2xBBB3xH12x", f.read(0x20))
        assert header[0] == "MsgStdBn"
        assert header[1] == 0xFEFF
        for i in range(header[4] - 1):
            header2 = unpack("<4sI8x", f.read(0x10))
            start = f.tell()

            if header2[0] == "LBL1":
                labels = LBL1(f)
            elif header2[0] == "TXTW": #custom section
                strings = TXTW(f, header2[1])
            
            f.seek(start + header2[1])
            f.seek(align(f.tell()))

        for entry in strings:
            o.write(entry + "\r\n".encode("UTF-16-LE"))
            o.write("----------------------------------------\r\n".encode("UTF-16-LE"))