feat(main.py): implement smart video seeking with keyframe optimization

croppa/main.py

@@ -13,8 +13,6 @@ import json
 class VideoEditor:
     # Configuration constants
     BASE_FRAME_DELAY_MS = 16  # ~60 FPS
-    KEY_REPEAT_RATE_SEC = 0.3
-    FAST_SEEK_ACTIVATION_TIME = 1.5
     SPEED_INCREMENT = 0.2
     MIN_PLAYBACK_SPEED = 0.1
     MAX_PLAYBACK_SPEED = 10.0
@@ -502,18 +500,69 @@ class VideoEditor:
         self.current_frame = target_frame
         self.load_current_frame()
 
+    def seek_video_smart(self, frames_delta: int):
+        """Seek using keyframe jumping for large jumps"""
+        target_frame = max(
+            0, min(self.current_frame + frames_delta, self.total_frames - 1)
+        )
+        
+        # For small jumps, use regular seeking
+        if abs(frames_delta) <= 10:
+            self.current_frame = target_frame
+            self.load_current_frame()
+            return
+        
+        # For larger jumps, use keyframe seeking
+        # Jump to nearest keyframe first, then seek forward
+        keyframe_interval = self._detect_keyframe_interval()
+        nearest_keyframe = (target_frame // keyframe_interval) * keyframe_interval
+        
+        # Seek to keyframe first
+        self.cap.set(cv2.CAP_PROP_POS_FRAMES, nearest_keyframe)
+        self.current_frame = nearest_keyframe
+        
+        # Then seek forward to target frame
+        frames_to_seek = target_frame - nearest_keyframe
+        for _ in range(frames_to_seek):
+            ret, frame = self.cap.read()
+            if not ret:
+                break
+            self.current_frame += 1
+        
+        self.current_display_frame = frame if 'frame' in locals() else None
+
+    def _detect_keyframe_interval(self):
+        """Detect the keyframe interval for the current video"""
+        # Try to get keyframe interval from video properties
+        try:
+            # Some backends support keyframe interval detection
+            keyframe_interval = self.cap.get(cv2.CAP_PROP_FRAME_COUNT) / self.cap.get(cv2.CAP_PROP_FPS)
+            if keyframe_interval > 0:
+                return int(keyframe_interval)
+        except:
+            pass
+        
+        # Fallback: estimate based on video characteristics
+        if self.fps >= 60:
+            return 60  # High FPS videos often have keyframes every 60 frames
+        elif self.fps >= 30:
+            return 30  # Standard videos have keyframes every 30 frames
+        else:
+            return 15  # Lower FPS videos have keyframes every 15 frames
+
     def seek_video_with_modifier(
         self, direction: int, shift_pressed: bool, ctrl_pressed: bool
     ):
         """Seek video with different frame counts based on modifiers"""
         if ctrl_pressed:
             frames = direction * 60  # Ctrl: 60 frames
+            self.seek_video_smart(frames)
         elif shift_pressed:
             frames = direction * 10  # Shift: 10 frames
+            self.seek_video_smart(frames)
         else:
             frames = direction * 1  # Default: 1 frame
-
-        self.seek_video(frames)
+            self.seek_video(frames)
 
     def start_auto_repeat_seek(self, key: int, direction: int, shift_pressed: bool, ctrl_pressed: bool):
         """Start auto-repeat seeking for a held key"""
@@ -544,12 +593,9 @@ class VideoEditor:
         
         # Do initial seek immediately
         self.seek_video_with_modifier(direction, shift_pressed, ctrl_pressed)
-        print(f"DEBUG: Started auto-repeat for key {key}")
 
     def stop_auto_repeat_seek(self):
         """Stop auto-repeat seeking"""
-        if self.auto_repeat_active:
-            print(f"DEBUG: Stopped auto-repeat")
         self.auto_repeat_active = False
         self.auto_repeat_key = None
         self.auto_repeat_direction = 0
@@ -1826,26 +1872,19 @@ class VideoEditor:
             delay = self.calculate_frame_delay() if self.is_playing else 1  # Very short delay for responsive key detection
             key = cv2.waitKey(delay) & 0xFF
             
-            # Debug key detection
-            if key != 255:
-                print(f"DEBUG: Key detected: {key} (auto_repeat_active: {self.auto_repeat_active}, auto_repeat_key: {self.auto_repeat_key})")
             
             # Handle auto-repeat - stop if a different key is pressed or no key for too long
             if key == 255 and self.auto_repeat_active:  # 255 means no key pressed
                 # Check if enough time has passed since last key activity (key was released)
                 if time.time() - self.last_key_activity > 0.1:  # 100ms timeout
-                    print(f"DEBUG: Key released - stopping auto-repeat")
                     self.stop_auto_repeat_seek()
             elif key != 255 and self.auto_repeat_active:
                 # A key is pressed, update the last key activity time
                 self.last_key_activity = time.time()
                 # If it's a different key, stop auto-repeat
                 if key != self.auto_repeat_key:
-                    print(f"DEBUG: Different key pressed ({key} vs {self.auto_repeat_key}) - stopping auto-repeat")
                     self.stop_auto_repeat_seek()
                 # If it's the same key, just update the last activity time (don't restart auto-repeat)
-                else:
-                    print(f"DEBUG: Same key pressed ({key}) - updating last activity time")
 
             # Get modifier key states
             window_title = "Image Editor" if self.is_image_mode else "Video Editor"