Merge pull request #2 from Bai-Mirror/codex/analyze-samsung_apple_compatible.heic-issue-ryyjbl

Fix parsing of Samsung infe boxes

base.py

@@ -1,6 +1,6 @@
 # pyheic_struct/base.py
 
-from typing import List
+from typing import List, Optional
 import struct
 from io import BytesIO
 
@@ -65,6 +65,7 @@ class Box:
             content_stream.write(child_data)
         return content_stream.getvalue()
 
+
     def build_box(self) -> bytes:
         """
         构建完整的盒 (头部 + 内容)，并返回其二进制数据。
@@ -80,7 +81,7 @@ class Box:
         
         return header_data + content_data
 
-    def find_box(self, box_type: str, recursive: bool = True) -> 'Box' | None:
+    def find_box(self, box_type: str, recursive: bool = True) -> Optional['Box']:
         """在子盒中查找指定类型的第一个盒子"""
         for child in self.children:
             if child.type == box_type:

heic_types.py

@@ -231,15 +231,35 @@ class ItemInfoEntryBox(FullBox):
                 self.item_name = stream[pos:name_end].decode('utf-8', errors='ignore')
                 
             elif self.version == 2:
-                # --- START FIX 3 (Parser) ---
-                # 恢复为原始顺序 (ID, ProtIdx, Type) 以正确 *读取* samsung.heic
                 self.item_id = struct.unpack('>I', stream[pos:pos+4])[0]
                 pos += 4
-                self.item_protection_index = struct.unpack('>H', stream[pos:pos+2])[0]
+
+                remaining = len(stream) - pos
+                if remaining >= 6:
+                    candidate_protection = struct.unpack('>H', stream[pos:pos+2])[0]
+                    candidate_type = stream[pos+2:pos+6]
+
+                    if candidate_protection <= 0x00FF and b'\x00' not in candidate_type:
+                        # 标准顺序: 2 字节保护索引 + 4 字节类型
+                        self.item_protection_index = candidate_protection
                         pos += 2
-                self.item_type = stream[pos:pos+4].decode('ascii').strip('\x00')
+                        type_bytes = candidate_type
                         pos += 4
-                # --- END FIX 3 ---
+                    else:
+                        # 三星文件: 直接写入类型 (如 'hvc1')，缺少保护索引
+                        self.item_protection_index = 0
+                        type_bytes = stream[pos:pos+4]
+                        pos += 4
+                elif remaining >= 4:
+                    # 某些三星文件缺少 2 字节的保护索引字段, 直接紧跟 4 字节类型
+                    self.item_protection_index = 0
+                    type_bytes = stream[pos:pos+4]
+                    pos += 4
+                else:
+                    # 无法获得完整的 4 字节类型
+                    type_bytes = b''
+
+                self.item_type = type_bytes.decode('ascii', errors='ignore').strip('\x00')
 
                 name_end = stream.find(b'\x00', pos)
                 if name_end == -1: name_end = len(stream)