97 lines
4.0 KiB
Python
97 lines
4.0 KiB
Python
import struct
|
|
from base import Box # <-- THIS IS THE KEY CHANGE
|
|
|
|
class ItemLocation:
|
|
# ... (rest of this class is unchanged)
|
|
def __init__(self, item_id, offset, length):
|
|
self.item_id = item_id
|
|
self.offset = offset
|
|
self.length = length
|
|
def __repr__(self):
|
|
return f"<ItemLocation ID={self.item_id} offset={self.offset} length={self.length}>"
|
|
|
|
class ItemLocationBox(Box):
|
|
# ... (rest of this class is unchanged)
|
|
def __init__(self, size: int, box_type: str, offset: int, raw_data: bytes):
|
|
super().__init__(size, box_type, offset, raw_data)
|
|
self.locations = []
|
|
self._parse_locations()
|
|
def _parse_locations(self):
|
|
# ... (all the parsing logic here is unchanged)
|
|
stream = self.raw_data
|
|
version_flags = struct.unpack('>I', stream[:4])[0]
|
|
sizes = struct.unpack('>H', stream[4:6])[0]
|
|
offset_size = (sizes >> 12) & 0x0F
|
|
length_size = (sizes >> 8) & 0x0F
|
|
base_offset_size = (sizes >> 4) & 0x0F
|
|
item_count = struct.unpack('>H', stream[6:8])[0]
|
|
current_pos = 8
|
|
for _ in range(item_count):
|
|
item_id = struct.unpack('>H', stream[current_pos : current_pos+2])[0]
|
|
current_pos += 2 # Skip construction_method
|
|
current_pos += 2 # Skip data_reference_index
|
|
current_pos += base_offset_size
|
|
extent_count = struct.unpack('>H', stream[current_pos : current_pos+2])[0]
|
|
current_pos += 2
|
|
if extent_count > 0:
|
|
offset = self._read_int(stream, current_pos, offset_size)
|
|
current_pos += offset_size
|
|
length = self._read_int(stream, current_pos, length_size)
|
|
current_pos += length_size
|
|
self.locations.append(ItemLocation(item_id, offset, length))
|
|
def _read_int(self, data, pos, size):
|
|
if size == 1: return data[pos]
|
|
if size == 2: return struct.unpack('>H', data[pos:pos+2])[0]
|
|
if size == 4: return struct.unpack('>I', data[pos:pos+4])[0]
|
|
if size == 8: return struct.unpack('>Q', data[pos:pos+8])[0]
|
|
return 0
|
|
|
|
class ItemInfoEntry:
|
|
"""A data class for one item described in an 'iinf' box."""
|
|
def __init__(self, item_id, item_type, item_name):
|
|
self.item_id = item_id
|
|
self.type = item_type
|
|
self.name = item_name
|
|
|
|
def __repr__(self):
|
|
return f"<ItemInfoEntry ID={self.item_id} type='{self.type}' name='{self.name}'>"
|
|
|
|
class ItemInfoBox(Box):
|
|
"""
|
|
A specialized class for the 'iinf' box.
|
|
Parses its own data to build a list of all available items.
|
|
"""
|
|
def __init__(self, size: int, box_type: str, offset: int, raw_data: bytes):
|
|
super().__init__(size, box_type, offset, raw_data)
|
|
|
|
self.entries: list[ItemInfoEntry] = []
|
|
self._parse_entries()
|
|
|
|
def _parse_entries(self):
|
|
# 'iinf' is a FullBox, so the first 4 bytes are version/flags
|
|
item_count = struct.unpack('>H', self.raw_data[4:6])[0]
|
|
|
|
# The children are 'infe' boxes, which are parsed by the generic parser
|
|
for infe_box in self.children:
|
|
if infe_box.type == 'infe':
|
|
# 'infe' is a FullBox (version, flags)
|
|
# version = infe_box.raw_data[0]
|
|
item_id = struct.unpack('>H', infe_box.raw_data[4:6])[0]
|
|
item_type = infe_box.raw_data[8:12].decode('ascii').strip('\x00')
|
|
item_name_bytes = infe_box.raw_data[12:]
|
|
item_name = item_name_bytes.decode('utf-8', errors='ignore').strip('\x00')
|
|
self.entries.append(ItemInfoEntry(item_id, item_type, item_name))
|
|
|
|
class PrimaryItemBox(Box):
|
|
"""
|
|
A specialized class for the 'pitm' box.
|
|
"""
|
|
def __init__(self, size: int, box_type: str, offset: int, raw_data: bytes):
|
|
super().__init__(size, box_type, offset, raw_data)
|
|
|
|
self.item_id: int = 0
|
|
self._parse_item_id()
|
|
|
|
def _parse_item_id(self):
|
|
# 'pitm' is a FullBox (version, flags)
|
|
self.item_id = struct.unpack('>H', self.raw_data[4:6])[0] |