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>
2026-01-19 12:34:45 +00:00
commit 406cc7c0c7
171 changed files with 13406 additions and 0 deletions
--- a/effects/scanlines.py
+++ b/effects/scanlines.py
@@ -0,0 +1,116 @@
+# /// script
+# requires-python = ">=3.10"
+# dependencies = ["numpy"]
+# ///
+"""
+@effect scanlines
+@version 1.0.0
+@author artdag
+
+@description
+VHS/CRT-style scan line shift. Horizontally displaces alternating lines
+to create analog video distortion. Great for retro/glitch aesthetics.
+
+@param amplitude float
+  @range 0 100
+  @default 10
+  Maximum shift amount in pixels. Bind to bass for reactive glitch.
+
+@param frequency float
+  @range 1 100
+  @default 10
+  Lines per cycle (affects pattern density).
+
+@param randomness float
+  @range 0 1
+  @default 0.5
+  0 = regular sine pattern, 1 = fully random shifts.
+
+@param line_gap int
+  @range 1 20
+  @default 1
+  Only shift every Nth line (1 = all lines).
+
+@param seed int
+  @default 42
+  Random seed for deterministic patterns.
+
+@state rng DeterministicRNG
+  Random number generator for reproducible results.
+
+@example
+  (effect scanlines :amplitude 20)
+
+@example
+  ;; Heavy glitch on bass
+  (effect scanlines :amplitude (bind bass :range [0 50]) :randomness 0.8)
+
+@example
+  ;; Reproducible scanlines
+  (effect scanlines :amplitude 30 :randomness 0.7 :seed 999)
+"""
+
+import numpy as np
+from pathlib import Path
+import sys
+
+# Import DeterministicRNG from same directory
+_effects_dir = Path(__file__).parent
+if str(_effects_dir) not in sys.path:
+    sys.path.insert(0, str(_effects_dir))
+from random import DeterministicRNG
+
+
+def process_frame(frame: np.ndarray, params: dict, state: dict) -> tuple:
+    """
+    Apply scan line shift to a video frame.
+
+    Args:
+        frame: Input frame as numpy array (H, W, 3) RGB uint8
+        params: Effect parameters
+            - amplitude: max shift in pixels (default 10)
+            - frequency: lines per cycle (default 10)
+            - randomness: 0-1 random vs sine (default 0.5)
+            - line_gap: shift every Nth line (default 1)
+            - seed: random seed (default 42)
+        state: Persistent state dict
+            - rng: DeterministicRNG instance
+
+    Returns:
+        Tuple of (processed_frame, new_state)
+    """
+    amplitude = params.get("amplitude", 10)
+    frequency = params.get("frequency", 10) or 1
+    randomness = params.get("randomness", 0.5)
+    line_gap = max(1, int(params.get("line_gap", 1)))
+    seed = int(params.get("seed", 42))
+
+    if state is None:
+        state = {}
+
+    # Initialize RNG
+    if "rng" not in state:
+        state["rng"] = DeterministicRNG(seed)
+    rng = state["rng"]
+
+    if amplitude == 0:
+        return frame, state
+
+    h, w = frame.shape[:2]
+    result = frame.copy()
+
+    for y in range(0, h, line_gap):
+        # Calculate shift amount
+        if randomness >= 1.0:
+            shift = int(rng.uniform(-amplitude, amplitude))
+        elif randomness <= 0:
+            shift = int(amplitude * np.sin(2 * np.pi * y / frequency))
+        else:
+            sine_shift = amplitude * np.sin(2 * np.pi * y / frequency)
+            rand_shift = rng.uniform(-amplitude, amplitude)
+            shift = int(sine_shift * (1 - randomness) + rand_shift * randomness)
+
+        if shift != 0:
+            result[y] = np.roll(result[y], shift, axis=0)
+
+    return result, state