feat(wan): Add Wan2.2 I2V support

mlx_video/postprocess.py

@@ -1,8 +1,42 @@
 
 import numpy as np
+from pathlib import Path
 from typing import Optional
 
 
+def save_video(frames: np.ndarray, output_path: str, fps: int = 16):
+    """Save video frames to MP4.
+
+    Args:
+        frames: Video frames [T, H, W, 3] uint8
+        output_path: Output file path
+        fps: Frames per second
+    """
+    try:
+        import imageio
+        writer = imageio.get_writer(output_path, fps=fps, codec="libx264", quality=8)
+        for frame in frames:
+            writer.append_data(frame)
+        writer.close()
+    except ImportError:
+        try:
+            import cv2
+            h, w = frames.shape[1], frames.shape[2]
+            fourcc = cv2.VideoWriter_fourcc(*"avc1")
+            writer = cv2.VideoWriter(output_path, fourcc, fps, (w, h))
+            for frame in frames:
+                writer.write(cv2.cvtColor(frame, cv2.COLOR_RGB2BGR))
+            writer.release()
+        except (ImportError, Exception):
+            # Last resort: save as individual PNGs
+            from PIL import Image
+            out_dir = Path(output_path).parent / Path(output_path).stem
+            out_dir.mkdir(parents=True, exist_ok=True)
+            for i, frame in enumerate(frames):
+                Image.fromarray(frame).save(out_dir / f"frame_{i:04d}.png")
+            print(f"  (no video encoder available, saved {len(frames)} frames to {out_dir}/)")
+
+
 def bilateral_filter(image: np.ndarray, d: int = 5, sigma_color: float = 75, sigma_space: float = 75) -> np.ndarray:
     """Apply bilateral filter to reduce grid artifacts while preserving edges.