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mirror of synced 2024-09-24 03:18:22 +02:00

Big improvement to IIDX Music DB handling, getting rid of all but one magic constant in the code.

This commit is contained in:
Jennifer Taylor 2023-07-29 18:41:14 +00:00
parent 2e3e6bfbd3
commit 1c54a329fe

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@ -17,6 +17,8 @@ class IIDXSong:
"""
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
@ -31,7 +33,7 @@ class IIDXMusicDB:
def __init__(self, data: bytes) -> None:
self.__songs: Dict[int, Tuple[IIDXSong, int]] = {}
self.__data = data
self.__parse_db(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
@ -53,86 +55,115 @@ class IIDXMusicDB:
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)
data = copy_over(data, bytes(song.difficulties), offset, 288)
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_db(self, data: bytes) -> None:
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
sig = struct.unpack_from(
"<4s",
magic, gameversion, songcount, indexcount = struct.unpack_from(
"<4sBxxxHHxxxx",
data,
0,
)
# Offset and difference lookup (not sure this is always right)
gameversion = data[4]
if gameversion == 20:
offset = 0xA420
leap = 0x320
elif gameversion == 21:
offset = 0xABF0
leap = 0x320
elif gameversion == 22:
offset = 0xB3C0
leap = 0x340
elif gameversion == 23:
offset = 0xBB90
leap = 0x340
elif gameversion == 24:
offset = 0xC360
leap = 0x340
elif gameversion == 25:
offset = 0xCB30
leap = 0x340
elif gameversion == 26:
offset = 0xD300
leap = 0x344
else:
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!")
if sig[0] != b"IIDX":
raise Exception(f"Invalid signature '{sig[0]}' found!")
def parse_string(string: bytes) -> str:
for i in range(len(string)):
if string[i] == 0:
string = string[:i]
break
return string.decode("shift-jis")
# Skip past index nodes, which are all 16-bit integers, and past 16 byte header.
offset = (indexcount * 2) + 0x10
# Load songs
while True:
try:
for songid in range(songcount):
songoffset = offset + (songid * leap)
if gameversion < 27:
songdata = struct.unpack_from(
"<64s64s64s64s24xB7xBBBBBB162xH",
data,
offset,
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],
)
except struct.error:
# Out of input!
break
songoffset = offset
offset = offset + leap
song = IIDXSong(
songdata[11],
parse_string(songdata[0]),
parse_string(songdata[1]),
parse_string(songdata[2]),
parse_string(songdata[3]),
[
songdata[5],
songdata[6],
songdata[7],
songdata[8],
songdata[9],
songdata[10],
],
songdata[4],
)
if song.artist == "event_data" and song.genre == "event_data":
continue
self.__songs[songdata[11]] = (song, songoffset)
self.__songs[song.id] = (song, songoffset)
return gameversion
@property
def songs(self) -> List[IIDXSong]: