feat(main.py): add marker looping functionality and update frame handling

croppa/main.py

@@ -105,6 +105,9 @@ class VideoEditor:
         self.cut_start_frame = None
         self.cut_end_frame = None
         
+        # Marker looping state
+        self.looping_between_markers = False
+
         # Display offset for panning when zoomed
         self.display_offset = [0, 0]
 
@@ -320,7 +323,15 @@ class VideoEditor:
         frames_to_advance = max(1, int(self.playback_speed))
         
         new_frame = self.current_frame + frames_to_advance
-        if new_frame >= self.total_frames:
+        
+        # Handle marker looping bounds
+        if self.looping_between_markers and self.cut_start_frame is not None and self.cut_end_frame is not None:
+            if new_frame >= self.cut_end_frame:
+                # Loop back to start marker
+                new_frame = self.cut_start_frame
+                self.current_frame = new_frame
+                return self.load_current_frame()
+        elif new_frame >= self.total_frames:
             new_frame = 0  # Loop - this will require a seek
             self.current_frame = new_frame
             return self.load_current_frame()
@@ -348,8 +359,18 @@ class VideoEditor:
                 # Hit actual end of video
                 print(f"Reached actual end of video at frame {self.current_frame} (reported: {self.total_frames})")
                 self.total_frames = self.current_frame
+                if self.looping_between_markers and self.cut_start_frame is not None:
+                    self.current_frame = self.cut_start_frame  # Loop back to start marker
+                else:
                     self.current_frame = 0  # Loop back to start
                 return self.load_current_frame()
+            
+            # Handle marker looping after successful frame load
+            if self.looping_between_markers and self.cut_start_frame is not None and self.cut_end_frame is not None:
+                if self.current_frame >= self.cut_end_frame:
+                    self.current_frame = self.cut_start_frame
+                    return self.load_current_frame()
+            
             return success
 
     def apply_crop_zoom_and_rotation(self, frame):
@@ -1017,6 +1038,28 @@ class VideoEditor:
         else:
             self.crop_rect = None
 
+    def toggle_marker_looping(self):
+        """Toggle looping between cut markers"""
+        # Check if both markers are set
+        if self.cut_start_frame is None or self.cut_end_frame is None:
+            print("Both markers must be set to enable looping. Use '1' and '2' to set markers.")
+            return False
+            
+        if self.cut_start_frame >= self.cut_end_frame:
+            print("Invalid marker range - start frame must be before end frame")
+            return False
+            
+        self.looping_between_markers = not self.looping_between_markers
+        
+        if self.looping_between_markers:
+            print(f"Marker looping ENABLED: frames {self.cut_start_frame} - {self.cut_end_frame}")
+            # Jump to start marker when enabling
+            self.seek_to_frame(self.cut_start_frame)
+        else:
+            print("Marker looping DISABLED")
+            
+        return True
+
 
 
     def adjust_crop_size(self, direction: str, expand: bool, amount: int = None):
@@ -1303,6 +1346,7 @@ class VideoEditor:
         print("  Ctrl+Scroll: Zoom in/out")
         print("  1: Set cut start point")
         print("  2: Set cut end point")
+        print("  T: Toggle loop between markers")
         if len(self.video_files) > 1:
             print("  N: Next video")
             print("  n: Previous video")
@@ -1398,6 +1442,8 @@ class VideoEditor:
             elif key == 13:  # Enter
                 output_name = self._get_next_edited_filename(self.video_path)
                 self.render_video(str(self.video_path.parent / output_name))
+            elif key == ord("t"):
+                self.toggle_marker_looping()
             
             # Individual direction controls using shift combinations we can detect
             elif key == ord("J"):  # Shift+i - expand up