Enable CI for robot devices with mocked versions (#398)

Co-authored-by: Simon Alibert <75076266+aliberts@users.noreply.github.com>

tests/mock_cv2.py

@@ -0,0 +1,66 @@
+from functools import cache
+
+import numpy as np
+
+CAP_PROP_FPS = 5
+CAP_PROP_FRAME_WIDTH = 3
+CAP_PROP_FRAME_HEIGHT = 4
+COLOR_RGB2BGR = 4
+COLOR_BGR2RGB = 4
+
+
+@cache
+def _generate_image(width: int, height: int):
+    return np.random.randint(0, 256, size=(height, width, 3), dtype=np.uint8)
+
+
+def cvtColor(color_image, color_convertion):  # noqa: N802
+    if color_convertion in [COLOR_RGB2BGR, COLOR_BGR2RGB]:
+        return color_image[:, :, [2, 1, 0]]
+    else:
+        raise NotImplementedError(color_convertion)
+
+
+class VideoCapture:
+    def __init__(self, *args, **kwargs):
+        self._mock_dict = {
+            CAP_PROP_FPS: 30,
+            CAP_PROP_FRAME_WIDTH: 640,
+            CAP_PROP_FRAME_HEIGHT: 480,
+        }
+        self._is_opened = True
+
+    def isOpened(self):  # noqa: N802
+        return self._is_opened
+
+    def set(self, propId: int, value: float) -> bool:  # noqa: N803
+        if not self._is_opened:
+            raise RuntimeError("Camera is not opened")
+        self._mock_dict[propId] = value
+        return True
+
+    def get(self, propId: int) -> float:  # noqa: N803
+        if not self._is_opened:
+            raise RuntimeError("Camera is not opened")
+        value = self._mock_dict[propId]
+        if value == 0:
+            if propId == CAP_PROP_FRAME_HEIGHT:
+                value = 480
+            elif propId == CAP_PROP_FRAME_WIDTH:
+                value = 640
+        return value
+
+    def read(self):
+        if not self._is_opened:
+            raise RuntimeError("Camera is not opened")
+        h = self.get(CAP_PROP_FRAME_HEIGHT)
+        w = self.get(CAP_PROP_FRAME_WIDTH)
+        ret = True
+        return ret, _generate_image(width=w, height=h)
+
+    def release(self):
+        self._is_opened = False
+
+    def __del__(self):
+        if self._is_opened:
+            self.release()