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bemaniutils/bemani/format/iidxmusicdb.py

180 lines
6.3 KiB
Python

import copy
import struct
from typing import Dict, List, Tuple
class IIDXSong:
def __init__(
self,
songid: int,
title: str,
english_title: str,
genre: str,
artist: str,
difficulties: List[int],
folder: int,
) -> None:
"""
Initialize a IIDX Song. Everything is self-explanatory except difficulties, which
is a list of integers representing the difficulty for SPN, SPH, SPA, DPN, DPH, DPA.
For IIDX 27 and above, there are 4 additional charts in the difficulties list for
B7, L7, B14 and L14.
"""
self.id = songid
self.title = title
self.english_title = english_title
self.genre = genre
self.artist = artist
self.difficulties = difficulties
self.folder = folder
class IIDXMusicDB:
def __init__(self, data: bytes) -> None:
self.__songs: Dict[int, Tuple[IIDXSong, int]] = {}
self.__data = data
self.__version = self.__parse_db(data)
def get_new_db(self) -> bytes:
# Write out a new music DB based on any possible changes to songs
data = copy.deepcopy(self.__data)
def format_string(string: str) -> bytes:
bdata = string.encode("shift-jis")
if len(bdata) < 64:
bdata = bdata + (b"\0" * (64 - len(bdata)))
return bdata
def copy_over(dst: bytes, src: bytes, base: int, offset: int) -> bytes:
return dst[: (base + offset)] + src + dst[(base + offset + len(src)) :]
for mid in self.__songs:
song, offset = self.__songs[mid]
data = copy_over(data, format_string(song.title), offset, 0)
data = copy_over(data, format_string(song.english_title), offset, 64)
data = copy_over(data, format_string(song.genre), offset, 128)
data = copy_over(data, format_string(song.artist), offset, 192)
data = copy_over(data, bytes([song.folder]), offset, 280)
if self.__version < 27:
# This is easy.
data = copy_over(data, bytes(song.difficulties), offset, 288)
elif self.__version >= 27:
# This is gross, but I'm too lazy to do it right.
data = copy_over(data, bytes([song.difficulties[6]]), offset, 288)
data = copy_over(data, bytes(song.difficulties[0:3]), offset, 289)
data = copy_over(data, bytes(song.difficulties[7:9]), offset, 292)
data = copy_over(data, bytes(song.difficulties[3:6]), offset, 294)
data = copy_over(data, bytes([song.difficulties[9]]), offset, 297)
return data
def __parse_string(self, string: bytes) -> str:
for i in range(len(string)):
if string[i] == 0:
string = string[:i]
break
return string.decode("shift-jis")
def __parse_db(self, data: bytes) -> int:
# Verify the signature
magic, gameversion, songcount, indexcount = struct.unpack_from(
"<4sBxxxHHxxxx",
data,
0,
)
if magic != b"IIDX":
raise Exception(f"Invalid signature '{magic}' found!")
# Stride lookup, which appears unfortunately hardcoded in the game DLL.
leap = {
20: 0x320,
21: 0x320,
22: 0x340,
23: 0x340,
24: 0x340,
25: 0x340,
26: 0x344,
27: 0x52C,
28: 0x52C,
}.get(gameversion)
if leap is None:
raise Exception(f"Unsupported game version {gameversion} found!")
# Skip past index nodes, which are all 16-bit integers, and past 16 byte header.
offset = (indexcount * 2) + 0x10
# Load songs
for songid in range(songcount):
songoffset = offset + (songid * leap)
if gameversion < 27:
songdata = struct.unpack_from(
"<64s64s64s64s24xB7xBBBBBB162xH",
data,
songoffset,
)
song = IIDXSong(
songid=songdata[11],
title=self.__parse_string(songdata[0]),
english_title=self.__parse_string(songdata[1]),
genre=self.__parse_string(songdata[2]),
artist=self.__parse_string(songdata[3]),
difficulties=[
songdata[5],
songdata[6],
songdata[7],
songdata[8],
songdata[9],
songdata[10],
],
folder=songdata[4],
)
elif gameversion >= 27:
# Heroic Verse and above have a completely different structure for song entries
songdata = struct.unpack_from(
"<64s64s64s64s24xB7x10B646xH",
data,
songoffset,
)
song = IIDXSong(
songid=songdata[15],
title=self.__parse_string(songdata[0]),
english_title=self.__parse_string(songdata[1]),
genre=self.__parse_string(songdata[2]),
artist=self.__parse_string(songdata[3]),
difficulties=[
songdata[6],
songdata[7],
songdata[8],
songdata[11],
songdata[12],
songdata[13],
songdata[5],
songdata[9],
songdata[10],
songdata[14],
],
folder=songdata[4],
)
if song.artist == "event_data" and song.genre == "event_data":
continue
self.__songs[song.id] = (song, songoffset)
return gameversion
@property
def songs(self) -> List[IIDXSong]:
return sorted(
[self.__songs[mid][0] for mid in self.__songs], key=lambda song: song.id
)
@property
def songids(self) -> List[int]:
return sorted([mid for mid in self.__songs])
def song(self, songid: int) -> IIDXSong:
return self.__songs[songid][0]