feat(main.py): implement aspect ratio preservation for video display

main.py

@@ -120,6 +120,20 @@ class MediaGrader:
         # Performance optimization: Thread pool for parallel operations
         self.thread_pool = ThreadPoolExecutor(max_workers=4)
     
+    def display_with_aspect_ratio(self, frame):
+        """Display frame while maintaining aspect ratio"""
+        if frame is None:
+            return
+            
+        # Log frame dimensions
+        height, width = frame.shape[:2]
+        
+        # Force window to resize to match the frame dimensions
+        cv2.resizeWindow("Media Grader", width, height)
+        
+        # Display the frame
+        cv2.imshow("Media Grader", frame)
+    
     def find_media_files(self) -> List[Path]:
         """Find all media files recursively in the directory"""
         media_files = []
@@ -958,7 +972,8 @@ class MediaGrader:
         # Draw timeline
         self.draw_timeline(frame)
 
-        cv2.imshow("Media Grader", frame)
+        # Maintain aspect ratio when displaying
+        self.display_with_aspect_ratio(frame)
 
     def display_multi_segment_frame(self):
         """Display multi-segment frame view"""
@@ -991,8 +1006,19 @@ class MediaGrader:
             row = i // grid_cols
             col = i % grid_cols
             
-            # Resize segment frame to fit grid cell
-            resized_segment = cv2.resize(segment_frame, (segment_width, segment_height))
+            # Resize segment frame to fit grid cell while maintaining aspect ratio
+            frame_height, frame_width = segment_frame.shape[:2]
+            seg_scale_x = segment_width / frame_width
+            seg_scale_y = segment_height / frame_height
+            seg_scale = min(seg_scale_x, seg_scale_y)
+            
+            new_seg_width = int(frame_width * seg_scale)
+            new_seg_height = int(frame_height * seg_scale)
+            resized_segment = cv2.resize(segment_frame, (new_seg_width, new_seg_height), interpolation=cv2.INTER_AREA)
+            
+            # Center the resized segment in the grid cell
+            y_offset = (segment_height - new_seg_height) // 2
+            x_offset = (segment_width - new_seg_width) // 2
             
             # Calculate position in combined frame
             y_start = row * segment_height
@@ -1000,8 +1026,17 @@ class MediaGrader:
             x_start = col * segment_width
             x_end = x_start + segment_width
             
-            # Place segment in combined frame
-            combined_frame[y_start:y_end, x_start:x_end] = resized_segment
+            # Place segment in combined frame (centered)
+            y_place_start = y_start + y_offset
+            y_place_end = y_place_start + new_seg_height
+            x_place_start = x_start + x_offset
+            x_place_end = x_place_start + new_seg_width
+            
+            # Ensure we don't go out of bounds
+            y_place_end = min(y_place_end, y_end)
+            x_place_end = min(x_place_end, x_end)
+            
+            combined_frame[y_place_start:y_place_end, x_place_start:x_place_end] = resized_segment
             
             # Add segment label
             segment_position = int((self.segment_positions[i] / self.total_frames) * 100)
@@ -1009,7 +1044,7 @@ class MediaGrader:
             cv2.putText(
                 combined_frame,
                 label_text,
-                (x_start + 5, y_start + 20),
+                (x_place_start + 5, y_place_start + 20),
                 cv2.FONT_HERSHEY_SIMPLEX,
                 0.5,
                 (255, 255, 255),
@@ -1018,7 +1053,7 @@ class MediaGrader:
             cv2.putText(
                 combined_frame,
                 label_text,
-                (x_start + 5, y_start + 20),
+                (x_place_start + 5, y_place_start + 20),
                 cv2.FONT_HERSHEY_SIMPLEX,
                 0.5,
                 (0, 0, 0),
@@ -1054,7 +1089,8 @@ class MediaGrader:
         # Draw multi-segment timeline
         self.draw_multi_segment_timeline(combined_frame)
 
-        cv2.imshow("Media Grader", combined_frame)
+        # Maintain aspect ratio when displaying
+        self.display_with_aspect_ratio(combined_frame)
 
     def draw_multi_segment_timeline(self, frame):
         """Draw timeline showing all segment positions"""
@@ -1410,6 +1446,9 @@ class MediaGrader:
         cv2.namedWindow("Media Grader", cv2.WINDOW_NORMAL)
         cv2.setMouseCallback("Media Grader", self.mouse_callback)
         
+        # Set initial window size to a reasonable default
+        cv2.resizeWindow("Media Grader", 1280, 720)
+
         while self.media_files and self.current_index < len(self.media_files):
             current_file = self.media_files[self.current_index]