Nymiro
47 lines
2.1 KiB
Python
47 lines
2.1 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 |