Initial commit: video effects processing system

Add S-expression based video effects pipeline with modular effect
definitions, constructs, and recipe files.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

effects/rgb_split.py

@@ -0,0 +1,106 @@
+# /// script
+# requires-python = ">=3.10"
+# dependencies = ["numpy", "opencv-python"]
+# ///
+"""
+@effect rgb_split
+@version 1.0.0
+@author artdag
+
+@description
+Chromatic aberration / RGB channel separation. Offsets red and blue channels
+in different directions, creating color fringing. Classic glitch aesthetic.
+
+@param amount float
+  @range 0 50
+  @default 10
+  Offset amount in pixels. Bind to bass for punchy glitch effect.
+
+@param angle float
+  @range 0 360
+  @default 0
+  Direction of split in degrees. 0 = horizontal, 90 = vertical.
+
+@param red_offset float
+  @range -50 50
+  @default 0
+  Override: specific red channel X offset (ignores amount/angle if set).
+
+@param blue_offset float
+  @range -50 50
+  @default 0
+  Override: specific blue channel X offset (ignores amount/angle if set).
+
+@example
+  (effect rgb_split :amount 15)
+
+@example
+  ;; Bass-reactive chromatic aberration
+  (effect rgb_split :amount (bind bass :range [0 30] :transform sqrt))
+
+@example
+  ;; Vertical split
+  (effect rgb_split :amount 20 :angle 90)
+"""
+
+import numpy as np
+import cv2
+import math
+
+
+def process_frame(frame: np.ndarray, params: dict, state: dict) -> tuple:
+    """
+    Apply RGB channel split to a video frame.
+
+    Args:
+        frame: Input frame as numpy array (H, W, 3) RGB uint8
+        params: Effect parameters
+            - amount: offset in pixels (default 10)
+            - angle: split direction in degrees (default 0)
+            - red_offset: override red X offset
+            - blue_offset: override blue X offset
+        state: Persistent state dict (unused)
+
+    Returns:
+        Tuple of (processed_frame, new_state)
+    """
+    amount = params.get("amount", 10)
+    angle = params.get("angle", 0)
+    red_override = params.get("red_offset")
+    blue_override = params.get("blue_offset")
+
+    # Calculate offsets
+    if red_override is not None or blue_override is not None:
+        # Use explicit offsets
+        r_x = int(red_override or 0)
+        r_y = 0
+        b_x = int(blue_override or 0)
+        b_y = 0
+    else:
+        # Calculate from amount and angle
+        angle_rad = math.radians(angle)
+        r_x = int(amount * math.cos(angle_rad))
+        r_y = int(amount * math.sin(angle_rad))
+        b_x = -r_x  # Blue goes opposite direction
+        b_y = -r_y
+
+    if r_x == 0 and r_y == 0 and b_x == 0 and b_y == 0:
+        return frame, state
+
+    h, w = frame.shape[:2]
+
+    # Split channels
+    r, g, b = frame[:, :, 0], frame[:, :, 1], frame[:, :, 2]
+
+    # Create translation matrices
+    M_r = np.float32([[1, 0, r_x], [0, 1, r_y]])
+    M_b = np.float32([[1, 0, b_x], [0, 1, b_y]])
+
+    # Translate red and blue channels
+    r_shifted = cv2.warpAffine(r, M_r, (w, h), borderMode=cv2.BORDER_REPLICATE)
+    b_shifted = cv2.warpAffine(b, M_b, (w, h), borderMode=cv2.BORDER_REPLICATE)
+
+    # Merge channels
+    result = np.stack([r_shifted, g, b_shifted], axis=-1)
+
+    return result, state