fix: Add 3D layout extraction from filename and update proposed filename generation

src/extractors/extractor.py

@@ -123,6 +123,7 @@ class MediaExtractor:
             "3d_layout": {
                 "sources": [
                     ("MediaInfo", "extract_3d_layout"),
+                    ("Filename", "extract_3d_layout"),
                     ("Default", "extract_3d_layout"),
                 ],
             },

src/extractors/filename_extractor.py

@@ -251,6 +251,33 @@ class FilenameExtractor:
         
         return None
 
+    @cached_method()
+    def extract_3d_layout(self) -> str | None:
+        """Extract 3D stereoscopic layout from filename or extension"""
+        # Ordered by specificity: most specific patterns first
+        patterns = [
+            (r'\b3D-SBS\b', '3D-SBS'),
+            (r'\b3D-OU\b', '3D-OU'),
+            (r'\b3D-HSBS\b', '3D-HSBS'),
+            (r'\b3D-HOU\b', '3D-HOU'),
+            (r'\bHalf[-.]?SBS\b', '3D-HSBS'),
+            (r'\bHalf[-.]?OU\b', '3D-HOU'),
+            (r'\bHSBS\b', '3D-HSBS'),
+            (r'\bHOU\b', '3D-HOU'),
+            (r'\bSBS\b', '3D-SBS'),
+            (r'\bOU\b', '3D-OU'),
+            (r'\b3D\b', '3D'),
+        ]
+        for pattern, result in patterns:
+            if re.search(pattern, self.file_name, re.IGNORECASE):
+                return result
+
+        # Fall back to mk3d extension as a 3D indicator
+        if self.file_path.suffix.lower() == '.mk3d':
+            return '3D'
+
+        return None
+
     @cached_method()
     def extract_movie_db(self) -> list[str] | None:
         """Extract movie database identifier from filename"""

src/extractors/mediainfo_extractor.py

@@ -389,6 +389,11 @@ class MediaInfoExtractor:
         # Use the constants function to get extension from format
         ext = get_extension_from_format(format_)
 
+        # Preserve mk3d extension when the source file already has it,
+        # even if MediaInfo doesn't report stereoscopic metadata
+        if self.file_path.suffix.lower() == '.mk3d':
+            return 'mk3d'
+
         # Special case: Matroska 3D uses mk3d extension
         if ext == "mkv" and self.is_3d():
             return "mk3d"

src/views/proposed_filename.py

@@ -48,6 +48,12 @@ class ProposedFilenameView:
         """Get the frame class"""
         return self._extractor.get("frame_class") or ""
 
+    @property
+    @conditional_decorators.wrap(",")
+    def _3d_layout(self) -> str:
+        """Get the 3D layout formatted with a leading comma if present"""
+        return self._extractor.get("3d_layout")
+
     @property
     @conditional_decorators.wrap(",")
     def _hdr(self) -> str:
@@ -81,7 +87,7 @@ class ProposedFilenameView:
     @property
     def rename_line(self) -> str:
         """Generate the proposed filename."""
-        result = f"{self._order}{self._title}{self._year}{self._special_info}{self._source} [{self._frame_class}{self._hdr},{self._audio_langs}]{self._db_info}.{self._extension}"
+        result = f"{self._order}{self._title}{self._year}{self._special_info}{self._source} [{self._frame_class}{self._3d_layout}{self._hdr},{self._audio_langs}]{self._db_info}.{self._extension}"
         return result.replace("/", "-").replace("\\", "-")
 
     def rename_line_formatted(self, file_path) -> str: