实现 AppleHandler 和 SamsungHandler 类，处理特定于供应商的 HEIC 特性，添加查找嵌入视频的逻辑

handlers/apple_handler.py

@@ -0,0 +1,14 @@
+from .base_handler import VendorHandler
+
+class AppleHandler(VendorHandler):
+    """
+    Handles Apple-specific HEIC features.
+    Apple's motion photos (Live Photos) are stored in a separate MOV file,
+    so we won't find an embedded video here.
+    """
+    # We override the method to make it explicit that Apple files are handled,
+    # even though the result is the same as the base class.
+    def find_motion_photo_offset(self, heic_file) -> int | None:
+        # We could add logic here later to find the ContentIdentifier
+        print("Apple HEIC detected. Motion photo video is in a separate .mov file, not embedded.")
+        return None

handlers/base_handler.py

@@ -0,0 +1,17 @@
+from __future__ import annotations
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from heic_file import HEICFile
+
+class VendorHandler:
+    """
+    Abstract base class for vendor-specific logic.
+    """
+    def find_motion_photo_offset(self, heic_file: HEICFile) -> int | None:
+        """
+        Tries to find the byte offset of the embedded motion photo video.
+        Returns the offset if found, otherwise None.
+        """
+        # Default behavior: no motion photo found.
+        return None

handlers/samsung_handler.py

@@ -0,0 +1,17 @@
+from .base_handler import VendorHandler
+
+class SamsungHandler(VendorHandler):
+    """Handles Samsung-specific HEIC features, like the embedded mpvd box."""
+
+    def find_motion_photo_offset(self, heic_file) -> int | None:
+        """
+        Searches for the 'mpvd' box which contains the video data.
+        """
+        for box in heic_file.boxes:
+            if box.type == 'mpvd':
+                print(f"Samsung 'mpvd' box found at offset {box.offset}")
+                # The video data starts right after the box header.
+                return box.offset + 8 
+        
+        print("Samsung HEIC detected, but no 'mpvd' box found.")
+        return None

heic_file.py

@@ -0,0 +1,76 @@
+import os
+from base import Box
+from parser import parse_boxes
+from heic_types import ItemLocationBox
+
+# Import handlers
+from handlers.base_handler import VendorHandler
+from handlers.apple_handler import AppleHandler
+from handlers.samsung_handler import SamsungHandler
+
+class HEICFile:
+    def __init__(self, filepath: str):
+        self.filepath = filepath
+        self._iloc_box: ItemLocationBox = None
+        self._ftyp_box: Box = None
+        self.handler: VendorHandler = None # Will hold our strategy object
+
+        with open(self.filepath, 'rb') as f:
+            file_size = os.fstat(f.fileno()).st_size
+            self.boxes = parse_boxes(f, file_size)
+            
+            self._find_essential_boxes(self.boxes)
+            self._detect_vendor()
+
+    def _find_essential_boxes(self, boxes: list[Box]):
+        """Recursively search for essential boxes."""
+        for box in boxes:
+            if box.type == 'iloc': self._iloc_box = box
+            if box.type == 'ftyp': self._ftyp_box = box
+            if box.children: self._find_essential_boxes(box.children)
+
+    def _detect_vendor(self):
+        """
+        Inspects the 'ftyp' box to determine the vendor and assign the correct handler.
+        """
+        if self._ftyp_box:
+            compatible_brands = self._ftyp_box.raw_data[4:].decode('ascii', errors='ignore')
+            if 'samsung' in compatible_brands.lower() or 'mpvd' in [b.type for b in self.boxes]:
+                 self.handler = SamsungHandler()
+                 return
+            if 'apple' in compatible_brands.lower() or 'MiHB' in compatible_brands:
+                 self.handler = AppleHandler()
+                 return
+        
+        # If no specific handler is found, use the base one.
+        print("Could not detect a specific vendor. Using default handler.")
+        self.handler = VendorHandler()
+
+
+    def get_item_data(self, item_id: int) -> bytes | None:
+        # ... (this method remains unchanged) ...
+        if not self._iloc_box:
+            print("Error: 'iloc' box not found.")
+            return None
+        location = next((loc for loc in self._iloc_box.locations if loc.item_id == item_id), None)
+        if not location:
+            print(f"Error: Item with ID {item_id} not found in 'iloc' box.")
+            return None
+        with open(self.filepath, 'rb') as f:
+            # IMPORTANT: iloc offsets are absolute from the start of the file.
+            # The mdat box's offset is not needed for this calculation.
+            f.seek(location.offset)
+            data = f.read(location.length)
+            return data
+
+    def get_motion_photo_data(self) -> bytes | None:
+        """
+        Delegates the search for motion photo data to the assigned vendor handler.
+        """
+        offset = self.handler.find_motion_photo_offset(self)
+        if offset is not None:
+            with open(self.filepath, 'rb') as f:
+                # We assume the video data goes to the end of the file from its offset
+                f.seek(offset)
+                return f.read()
+        return None

heic_types.py

@@ -1,4 +1,3 @@
-# In heic_types.py
 import struct
 from base import Box  # <-- THIS IS THE KEY CHANGE
 
@@ -29,7 +28,7 @@ class ItemLocationBox(Box):
         current_pos = 8
         for _ in range(item_count):
             item_id = struct.unpack('>H', stream[current_pos : current_pos+2])[0]
-            current_pos += 4 # Skip item_id and construction_method
+            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]

main.py

@@ -1,44 +1,27 @@
-from base import Box
-from parser import parse_boxes
-from heic_types import ItemLocationBox
-from typing import List
-import os
-
-def print_box_tree(boxes: List[Box], indent: int = 0):
-    for box in boxes:
-        print("  " * indent + str(box))
-        
-        if isinstance(box, ItemLocationBox):
-            for loc in box.locations[:5]:
-                print("  " * (indent + 1) + str(loc))
-            if len(box.locations) > 5:
-                print("  " * (indent + 1) + f"... and {len(box.locations) - 5} more locations")
-
-        if box.children:
-            print_box_tree(box.children, indent + 1)
+from heic_file import HEICFile
 
 def main():
-    # Test with the Apple HEIC file
-    print("--- Analyzing Apple HEIC file ---")
-    try:
-        with open('apple.heic', 'rb') as f:
-            file_size = os.fstat(f.fileno()).st_size
-            top_level_boxes = parse_boxes(f, file_size)
-            print_box_tree(top_level_boxes)
-    except FileNotFoundError:
-        print("Error: apple.heic not found.")
+    print("--- Processing Samsung HEIC file ---")
+    samsung_heic = HEICFile('samsung.heic')
+    samsung_video_data = samsung_heic.get_motion_photo_data()
+    
+    if samsung_video_data:
+        output_filename = 'samsung_motion_photo.mp4'
+        with open(output_filename, 'wb') as f:
+            f.write(samsung_video_data)
+        print(f"Successfully extracted motion photo to '{output_filename}' ({len(samsung_video_data)} bytes)")
 
     print("\n" + "="*40 + "\n")
 
-    # Test with the Samsung HEIC file
-    print("--- Analyzing Samsung HEIC file ---")
-    try:
-        with open('samsung.heic', 'rb') as f:
-            file_size = os.fstat(f.fileno()).st_size
-            top_level_boxes = parse_boxes(f, file_size)
-            print_box_tree(top_level_boxes)
-    except FileNotFoundError:
-        print("Error: samsung.heic not found.")
+    print("--- Processing Apple HEIC file ---")
+    apple_heic = HEICFile('apple.heic')
+    apple_video_data = apple_heic.get_motion_photo_data()
+
+    if apple_video_data:
+        # This block should not be reached for Apple files
+        print("Extracted embedded video from Apple file (this is unexpected).")
+    else:
+        print("No embedded motion photo found in Apple file, as expected.")
 
 
 if __name__ == "__main__":