Update app.py

app.py

@@ -147,35 +147,65 @@ def interpolate_frames(video_path, target_fps=30):
             print("Not enough frames for interpolation.")
             return video_path
         
-        # Calculate interpolation factor
-        interpolation_factor = int(target_fps / original_fps)
-        interpolated_frames = []
+        # Calculate interpolation factor (can be fractional)
+        interpolation_factor = target_fps / original_fps
         
-        print(f"Interpolating with factor: {interpolation_factor}")
+        # For fractional factors, we need different approach
+        if interpolation_factor <= 1:
+            print("Interpolation factor too low. Skipping.")
+            return video_path
+            
+        print(f"Interpolating with factor: {interpolation_factor:.2f}")
+        print(f"Total frames to process: {len(frames)}")
         
         # Perform frame interpolation
-        for i in range(len(frames) - 1):
-            interpolated_frames.append(frames[i])
-            
-            # Generate intermediate frames
-            for j in range(1, interpolation_factor):
-                alpha = j / interpolation_factor
-                # Use weighted average for simple interpolation
-                interpolated_frame = cv2.addWeighted(
-                    frames[i], 1 - alpha,
-                    frames[i + 1], alpha,
-                    0
-                )
-                interpolated_frames.append(interpolated_frame)
+        interpolated_frames = []
         
-        # Add the last frame
-        interpolated_frames.append(frames[-1])
+        if interpolation_factor == int(interpolation_factor):
+            # Integer factor - simple interpolation
+            factor = int(interpolation_factor)
+            for i in range(len(frames) - 1):
+                interpolated_frames.append(frames[i])
+                # Generate intermediate frames
+                for j in range(1, factor):
+                    alpha = j / factor
+                    interpolated_frame = cv2.addWeighted(
+                        frames[i], 1 - alpha,
+                        frames[i + 1], alpha,
+                        0
+                    )
+                    interpolated_frames.append(interpolated_frame)
+            interpolated_frames.append(frames[-1])
+        else:
+            # Fractional factor - use different approach
+            # For 25 -> 60 fps, we need to add selective frames
+            for i in range(len(frames) - 1):
+                interpolated_frames.append(frames[i])
+                # Add intermediate frame for smoother motion
+                if i % 2 == 0:  # Add extra frame every other original frame
+                    alpha = 0.4  # Blend ratio
+                    interpolated_frame = cv2.addWeighted(
+                        frames[i], 1 - alpha,
+                        frames[i + 1], alpha,
+                        0
+                    )
+                    interpolated_frames.append(interpolated_frame)
+            interpolated_frames.append(frames[-1])
+        
+        print(f"Total interpolated frames: {len(interpolated_frames)}")
         
         # Save the interpolated video
         output_path = video_path.replace('.mp4', '_interpolated.mp4')
-        fourcc = cv2.VideoWriter_fourcc(*'mp4v')
+        
+        # Use H.264 codec for better compatibility
+        fourcc = cv2.VideoWriter_fourcc(*'H264')
         out = cv2.VideoWriter(output_path, fourcc, target_fps, (width, height))
         
+        if not out.isOpened():
+            # Fallback to mp4v if H264 not available
+            fourcc = cv2.VideoWriter_fourcc(*'mp4v')
+            out = cv2.VideoWriter(output_path, fourcc, target_fps, (width, height))
+        
         for frame in interpolated_frames:
             out.write(frame)
         out.release()
@@ -185,6 +215,8 @@ def interpolate_frames(video_path, target_fps=30):
         
     except Exception as e:
         print(f"Error during frame interpolation: {e}")
+        import traceback
+        traceback.print_exc()
         return video_path  # Return original if interpolation fails
 
 # --- Initialization ---
@@ -395,7 +427,7 @@ with gr.Blocks(theme=gr.themes.Soft(), css=".gradio-container {max-width: 960px
                     minimum=0.5,
                     maximum=5.0,
                     step=0.1,
-                    value=0.5,
+                    value=1.0,
                     info="Lower values produce smoother but less controlled motion"
                 )
             
@@ -412,10 +444,10 @@ with gr.Blocks(theme=gr.themes.Soft(), css=".gradio-container {max-width: 960px
                 fps_slider = gr.Slider(
                     label="Target FPS",
                     minimum=24,
-                    maximum=60,
-                    step=6,
-                    value=60,
-                    info="Higher FPS for smoother motion (uses frame interpolation)"
+                    maximum=50,
+                    step=1,
+                    value=30,
+                    info="Higher FPS for smoother motion. 30 FPS recommended, 50 FPS maximum"
                 )
             
             submit_button = gr.Button("🎥 Generate Video", variant="primary", size="lg")