initial commit, with UR env connected to sim backend

examples/ur_sim/saver.py

@@ -0,0 +1,40 @@
+import logging
+import pathlib
+
+import imageio
+import numpy as np
+from openpi_client.runtime import subscriber as _subscriber
+# import openpi.transforms as transforms
+from typing_extensions import override
+
+
+class VideoSaver(_subscriber.Subscriber):
+    """Saves episode data."""
+
+    def __init__(self, out_path: pathlib.Path, subsample: int = 1) -> None:
+        self._out_path = out_path
+        self._images: list[np.ndarray] = []
+        self._subsample = subsample
+
+    @override
+    def on_episode_start(self) -> None:
+        self._images = []
+
+    @override
+    def on_step(self, observation: dict, action: dict) -> None:
+        img1 = observation["observation/base_0_camera/rgb/image"]
+        img2 = observation["observation/wrist_0_camera/rgb/image"]
+        big_img = np.concatenate([img1, img2], axis=1)
+        self._images.append(big_img)
+        # im = observation["image"][0]  # [C, H, W]
+        # im = np.transpose(im, (1, 2, 0))  # [H, W, C]
+        # self._images.append(im)
+
+    @override
+    def on_episode_end(self) -> None:
+        logging.info(f"Saving video to {self._out_path}")
+        imageio.mimwrite(
+            self._out_path,
+            [np.asarray(x) for x in self._images[:: self._subsample]],
+            fps=20 // max(1, self._subsample),
+        )