*.bin.gz converter script for Hyrule Warriors (Wii U only prob bc big endian)

hyrule_convert.py

'''
word 0 = chunk_size (read 0x10000 bytes, compress, store)
word 1 = num_chunks
word 2 = dec_size
table, compressed chunk size + 4 (there's a size word at the start of the section)
align to 0x80
(write enc_chunk_size, enc_chunk, align to 0x80) * num_chunks
'''

from struct import unpack, pack
from io import BytesIO
import zlib, sys

def align_128(f):
    if (f.tell() % 0x80):
        f.seek(0x80 - (f.tell() % 0x80), 1)

def write_128(o):
    if (o.tell() % 0x80):
        o.write(b"\x00" * (0x80 - (o.tell() % 0x80)))

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

def hyrule_decompress(filename, outname):
    with open(filename, "rb") as f:
        with open(outname, "wb") as o:
            header = unpack(">3I", f.read(12))
            section_sizes = unpack(">%dI" % header[1], f.read(4*header[1]))
            align_128(f)
            for i in range(header[1]):
                size = full(f)
                o.write(zlib.decompress(f.read(size)))
                align_128(f)

def hyrule_compress(filename, outname):
    with open(filename, "rb") as f:
        with open(outname, "wb+") as o:
            section_sizes = []
            f.seek(0, 2)
            if not f.tell() % 0x10000: #multiple of 0x10000
                section_count = int(f.tell() / 0x10000)
            else: #add one chunk for overflow bytes
                section_count = int(f.tell() / 0x10000) + 1

            o.write(pack(">I", 0x10000))
            o.write(pack(">I", section_count))
            o.write(pack(">I", f.tell()))
            o.write(b"\x00\x00\x00\x00" * section_count) #sizes, will fix later
            write_128(o)
            f.seek(0) #start of file, time to start compressing

            for i in range(section_count):
                data = BytesIO(zlib.compress(f.read(0x10000), 9))
                data.seek(0, 2)
                section_sizes.append(data.tell())
                data.seek(0)
                o.write(pack(">I", section_sizes[-1]))
                o.write(data.read())
                write_128(o)

            o.seek(12) #go back to write section table
            for i in range(section_count):
                o.write(pack(">I", section_sizes[i] + 4))

if __name__ == "__main__":
    if len(sys.argv) == 4:
        if sys.argv[1] == "decompress":
            hyrule_decompress(sys.argv[2], sys.argv[3])
        elif sys.argv[1] == "compress":
            hyrule_compress(sys.argv[2], sys.argv[3])
        else:
            print('unknown option, expected "decompress" or "compress"')
    print("hyrule_convert.py <de/compress> <filename> <outname>")