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mirror of synced 2024-12-21 10:25:54 +01:00
bemaniutils/bemani/format/twodx.py

103 lines
3.3 KiB
Python

import struct
from typing import Dict, List, Optional
class TwoDX:
"""
Packer/unpacker class for a bytestream representing a `.2dx` file.
"""
def __init__(self, data: Optional[bytes] = None) -> None:
self.__name: Optional[str] = None
self.__files: Dict[str, bytes] = {}
if data is not None:
self.__parse_file(data)
def __parse_file(self, data: bytes) -> None:
# Parse file header
(name, headerSize, numfiles) = struct.unpack('<16sII', data[0:24])
self.__name = name.split(b'\x00')[0].decode('ascii')
if headerSize != (72 + (4 * numfiles)):
raise Exception('Unrecognized 2dx file header!')
fileoffsets = struct.unpack('<' + ''.join(['I' for _ in range(numfiles)]), data[72:(72 + (4 * numfiles))])
fileno = 1
for offset in fileoffsets:
(magic, headerSize, wavSize, _, track, _, attenuation, loop) = struct.unpack(
'<4sIIhhhhi',
data[offset:(offset + 24)],
)
if magic != b'2DX9':
raise Exception('Unrecognized entry in file!')
if headerSize != 24:
raise Exception('Unrecognized subheader in file!')
wavOffset = offset + headerSize
wavData = data[wavOffset:(wavOffset + wavSize)]
self.__files[f'{self.__name}_{fileno}.wav'] = wavData
fileno = fileno + 1
@property
def name(self) -> str:
if self.__name is None:
raise Exception("Logic error, tried to get name of 2dx file before setting it or parsing file!")
return self.__name
def set_name(self, name: str) -> None:
if len(name) <= 16:
self.__name = name
else:
raise Exception('Name of archive too long!')
@property
def filenames(self) -> List[str]:
return [f for f in self.__files]
def read_file(self, filename: str) -> bytes:
return self.__files[filename]
def write_file(self, filename: str, data: bytes) -> None:
self.__files[filename] = data
def get_new_data(self) -> bytes:
if not self.__files:
raise Exception('No files to write!')
if not self.__name:
raise Exception('2dx archive name not set!')
name = self.__name.encode('ascii')
while len(name) < 16:
name = name + b'\x00'
filedata = [self.__files[x] for x in self.__files]
# Header length is also the base offset for the first file
baseoffset = 72 + (4 * len(filedata))
data = [struct.pack('<16sII', name, baseoffset, len(filedata)) + (b'\x00' * 48)]
# Calculate offset this will go to
for bytedata in filedata:
# Add where this file will go, then calculate the length
data.append(struct.pack('<I', baseoffset))
baseoffset = baseoffset + 24 + len(bytedata)
# Now output the headers and files
for bytedata in filedata:
data.append(struct.pack(
'<4sIIhhhhi',
b'2DX9',
24,
len(bytedata),
0x3231,
-1,
64,
1,
0,
))
data.append(bytedata)
return b''.join(data)