initial commit and version 1.0

moviepy/video/fx/FadeIn.py

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+from dataclasses import dataclass
+
+import numpy as np
+
+from moviepy.Clip import Clip
+from moviepy.Effect import Effect
+
+
+@dataclass
+class FadeIn(Effect):
+    """Makes the clip progressively appear from some color (black by default),
+    over ``duration`` seconds at the beginning of the clip. Can be used for
+    masks too, where the initial color must be a number between 0 and 1.
+
+    For cross-fading (progressive appearance or disappearance of a clip
+    over another clip, see ``CrossFadeIn``
+    """
+
+    duration: float
+    initial_color: list = None
+
+    def apply(self, clip: Clip) -> Clip:
+        """Apply the effect to the clip."""
+        if self.initial_color is None:
+            self.initial_color = 0 if clip.is_mask else [0, 0, 0]
+
+        self.initial_color = np.array(self.initial_color)
+
+        def filter(get_frame, t):
+            if t >= self.duration:
+                return get_frame(t)
+            else:
+                fading = 1.0 * t / self.duration
+                return fading * get_frame(t) + (1 - fading) * self.initial_color
+
+        return clip.transform(filter)