Taiko Wii 4+ Fumen Endianness Converter

'''
TAIKO WII 4 FUMEN FORMAT (seems like games as recent as 3ds 3 still use this format)
(found by decompiling FumenViewer @ http://web.archive.org/web/20130718194918/http://forum.owataiko.com/viewtopic.php?f=4&t=356)

0x0: 36 "hantei notes". each one is 3 float32's.
0x200: int32 num_section, int32 unknown

0x208: num_section sections follow
    float32 bpm, float32 start_time, int8 gogo, int8 section_line, int16 unknown
    6 "bunkis". each one is 1 int32
    int32 unknown
    3 routes follow
        int16 num_notes, int16 unknown, float32 scroll
        num_notes notes follow
            int32 note_type
            float32 headerI1 (note_time = bpm * headerI1 / 5000)
            int32 item, float32 unknown1, int16 hit, int16 score_inc, float32 length
            if note_type is 6, 9 or 98:
                int32 unknown, int32 unknown
'''

import struct
import sys
import shutil
import argparse

parser = argparse.ArgumentParser(description='Taiko Wii 4+ Fumen Endianness Converter')
parser.add_argument('direction', help='set to bl to convert from big to little endian, or lb to convert from little to big endian')
parser.add_argument('in.bin')
parser.add_argument('out.bin')
if len(sys.argv) == 1:
    parser.print_help()
    sys.exit()
args = parser.parse_args()

ibo = obo = None # in byte order, out byte order
try:
    ibo = {'lb': '<', 'bl': '>'}[args.direction.lower()]
except KeyError:
    sys.exit('error: invalid direction "%s"!' % args.direction.lower())
obo = '>' if ibo == '<' else '<'

in_path = getattr(args, 'in.bin')
out_path = getattr(args, 'out.bin')

same_file = out_path == in_path

if same_file:
    out_path += '.r'

with open(in_path, 'rb') as fin:
    with open(out_path, 'wb') as fout:
        for hanteiI in range(36 * 3):
            fout.write(struct.pack(obo + 'f', struct.unpack(ibo + 'f', fin.read(4))[0])) # hantei notes

        while fin.tell() != 0x200:
            fout.write(struct.pack(obo + 'I', struct.unpack(ibo + 'I', fin.read(4))[0])) # header stuff like tamashii rate

        num_section = struct.unpack(ibo + 'I', fin.read(4))[0]
        fout.write(struct.pack(obo + 'I', num_section)) # num_section
        fout.write(struct.pack(obo + 'I', struct.unpack(ibo + 'I', fin.read(4))[0])) # unknown

        for sectionI in range(num_section):
            fout.write(struct.pack(obo + 'f', struct.unpack(ibo + 'f', fin.read(4))[0])) # bpm
            fout.write(struct.pack(obo + 'f', struct.unpack(ibo + 'f', fin.read(4))[0])) # start_time
            fout.write(struct.pack(obo + 'B', struct.unpack(ibo + 'B', fin.read(1))[0])) # gogo
            fout.write(struct.pack(obo + 'B', struct.unpack(ibo + 'B', fin.read(1))[0])) # section_line
            fout.write(struct.pack(obo + 'H', struct.unpack(ibo + 'H', fin.read(2))[0])) # unknown

            for bunkiI in range(6):
                fout.write(struct.pack(obo + 'I', struct.unpack(ibo + 'I', fin.read(4))[0])) # bunkis

            fout.write(struct.pack(obo + 'I', struct.unpack(ibo + 'I', fin.read(4))[0])) # unknown

            for routeI in range(3):
                num_notes = struct.unpack(ibo + 'H', fin.read(2))[0]
                fout.write(struct.pack(obo + 'H', num_notes)) # num_notes
                fout.write(struct.pack(obo + 'H', struct.unpack(ibo + 'H', fin.read(2))[0])) # unknown
                fout.write(struct.pack(obo + 'f', struct.unpack(ibo + 'f', fin.read(4))[0])) # scroll

                for noteI in range(num_notes):
                    note_type = struct.unpack(ibo + 'I', fin.read(4))[0]
                    fout.write(struct.pack(obo + 'I', note_type)) # note_type
                    fout.write(struct.pack(obo + 'f', struct.unpack(ibo + 'f', fin.read(4))[0])) # headerI1
                    fout.write(struct.pack(obo + 'I', struct.unpack(ibo + 'I', fin.read(4))[0])) # item
                    fout.write(struct.pack(obo + 'f', struct.unpack(ibo + 'f', fin.read(4))[0])) # unknown1
                    fout.write(struct.pack(obo + 'H', struct.unpack(ibo + 'H', fin.read(2))[0])) # hit
                    fout.write(struct.pack(obo + 'H', struct.unpack(ibo + 'H', fin.read(2))[0])) # score_inc
                    fout.write(struct.pack(obo + 'f', struct.unpack(ibo + 'f', fin.read(4))[0])) # length

                    if note_type in [6, 9, 98]:
                        fout.write(struct.pack(obo + 'I', struct.unpack(ibo + 'I', fin.read(4))[0])) # unknown
                        fout.write(struct.pack(obo + 'I', struct.unpack(ibo + 'I', fin.read(4))[0])) # unknown

if same_file:
    shutil.move(out_path, in_path)