initial commit and version 1.0

moviepy/video/fx/Scroll.py

@@ -0,0 +1,57 @@
+from moviepy.Effect import Effect
+
+
+class Scroll(Effect):
+    """Effect that scrolls horizontally or vertically a clip, e.g. to make end credits
+
+    Parameters
+    ----------
+    w, h
+      The width and height of the final clip. Default to clip.w and clip.h
+
+    x_speed, y_speed
+      The speed of the scroll in the x and y directions.
+
+    x_start, y_start
+      The starting position of the scroll in the x and y directions.
+
+
+    apply_to
+      Whether to apply the effect to the mask too.
+    """
+
+    def __init__(
+        self,
+        w=None,
+        h=None,
+        x_speed=0,
+        y_speed=0,
+        x_start=0,
+        y_start=0,
+        apply_to="mask",
+    ):
+        self.w = w
+        self.h = h
+        self.x_speed = x_speed
+        self.y_speed = y_speed
+        self.x_start = x_start
+        self.y_start = y_start
+        self.apply_to = apply_to
+
+    def apply(self, clip):
+        """Apply the effect to the clip."""
+        if self.h is None:
+            self.h = clip.h
+
+        if self.w is None:
+            self.w = clip.w
+
+        x_max = self.w - 1
+        y_max = self.h - 1
+
+        def filter(get_frame, t):
+            x = int(max(0, min(x_max, self.x_start + round(self.x_speed * t))))
+            y = int(max(0, min(y_max, self.y_start + round(self.y_speed * t))))
+            return get_frame(t)[y : y + self.h, x : x + self.w]
+
+        return clip.transform(filter, apply_to=self.apply_to)