add dynamic import for cv2 and pyrealsense2

tests/mock_opencv.py

@@ -0,0 +1,41 @@
+import cv2
+import numpy as np
+
+
+class MockVideoCapture(cv2.VideoCapture):
+    image = {
+        "480x640": np.random.randint(0, 256, size=(480, 640, 3), dtype=np.uint8),
+        "720x1280": np.random.randint(0, 256, size=(720, 1280, 3), dtype=np.uint8),
+    }
+
+    def __init__(self, *args, **kwargs):
+        self._mock_dict = {
+            cv2.CAP_PROP_FPS: 30,
+            cv2.CAP_PROP_FRAME_WIDTH: 640,
+            cv2.CAP_PROP_FRAME_HEIGHT: 480,
+        }
+
+    def isOpened(self):  # noqa: N802
+        return True
+
+    def set(self, propId: int, value: float) -> bool:  # noqa: N803
+        self._mock_dict[propId] = value
+        return True
+
+    def get(self, propId: int) -> float:  # noqa: N803
+        value = self._mock_dict[propId]
+        if value == 0:
+            if propId == cv2.CAP_PROP_FRAME_HEIGHT:
+                value = 480
+            elif propId == cv2.CAP_PROP_FRAME_WIDTH:
+                value = 640
+        return value
+
+    def read(self):
+        h = self.get(cv2.CAP_PROP_FRAME_HEIGHT)
+        w = self.get(cv2.CAP_PROP_FRAME_WIDTH)
+        ret = True
+        return ret, self.image[f"{h}x{w}"]
+
+    def release(self):
+        pass