add checks FILM.py

FILM.py

@@ -53,15 +53,17 @@ def _recursive_generator(frame1, frame2, num_recursions, interpolator):
     if num_recursions == 0:
         yield frame1 # exit condition
     else:
-        time = np.full(shape=(1,), fill_value=0.5, dtype=np.float32)
+        dt_value = np.full(shape=(1,), fill_value=0.5, dtype=np.float32)
         mid_frame = interpolator(
-            np.expand_dims(frame1, axis=0), np.expand_dims(frame2, axis=0), time)[0]
+            np.expand_dims(frame1, axis=0), np.expand_dims(frame2, axis=0), dt_value)[0]
         yield from _recursive_generator(frame1, mid_frame, num_recursions - 1, interpolator) # 1st half
         yield from _recursive_generator(mid_frame, frame2, num_recursions - 1, interpolator) # 2nd half
 
 def interpolate_recursively(frames, num_recursions, interpolator):
     """Apply recursive interpolation to a list of input frames."""
     n = len(frames)
+    if n == 0:
+        raise ValueError("No input frames found.")
     for i in range(1, n):
         yield from _recursive_generator(frames[i - 1], frames[i], num_recursions, interpolator)
     yield frames[-1]
@@ -69,6 +71,12 @@ def interpolate_recursively(frames, num_recursions, interpolator):
 def process_keyframes(input_folder, output_folder, fps=30, num_recursions=3):
     """Process keyframes to create an interpolated video, using functions above"""
     keyframes = sorted(glob(os.path.join(input_folder, '*.png')))
+    if not keyframes:
+        raise ValueError(f"No PNG keyframes found in {input_folder}")
+
+    # Ensure the output folder exists
+    os.makedirs(output_folder, exist_ok=True)
+    
     frames = [preprocess_image(frame).numpy() for frame in keyframes]
     
     interpolator = Interpolator()