添加 Box 类及其子类 ItemLocationBox 的实现，包含初始化和解析逻辑

base.py

@@ -0,0 +1,15 @@
+from typing import List
+
+class Box:
+    """
+    Represents a generic ISOBMFF box. This is a simple data container.
+    """
+    def __init__(self, size: int, box_type: str, offset: int, raw_data: bytes):
+        self.size = size
+        self.type = box_type
+        self.offset = offset
+        self.raw_data = raw_data
+        self.children: List['Box'] = [] # Initially empty
+
+    def __repr__(self) -> str:
+        return f"<Box '{self.type}' size={self.size} offset={self.offset}>"