opencv.py

lerobot/common/robot_devices/cameras/opencv.py

@@ -50,6 +50,24 @@ def find_camera_indices(raise_when_empty=False, max_index_search_range=MAX_OPENC
 
     return camera_ids
 
+def find_camera_ports(raise_when_empty=False):
+    camera_ports = []
+    for port in Path("/dev").glob("video*"):
+        port = str(port)
+        camera = cv2.VideoCapture(port)
+        is_open = camera.isOpened()
+        camera.release()
+
+        if is_open:
+            print(f"Camera found at port {port}")
+            camera_ports.append(port)
+
+    if raise_when_empty and len(camera_ports) == 0:
+        raise OSError(
+            "Not a single camera was detected. Try re-plugging, or re-installing `opencv2`, or your camera driver, or make sure your camera is compatible with opencv2."
+        )
+
+    return camera_ports
 
 def save_image(img_array, camera_index, frame_index, images_dir):
     img = Image.fromarray(img_array)
@@ -59,11 +77,16 @@ def save_image(img_array, camera_index, frame_index, images_dir):
 
 
 def save_images_from_cameras(
-    images_dir: Path, camera_ids=None, fps=None, width=None, height=None, record_time_s=2
+    images_dir: Path, camera_ids: list[int] | list[str] | None=None, fps=None, width=None, height=None, record_time_s=2
 ):
+    
     if camera_ids is None:
-        print("Finding available camera indices")
+        print("Finding available camera indices through '/dev/video*' ports")
-        camera_ids = find_camera_indices()
+        camera_ids = find_camera_ports()
+
+        if len(camera_ids) == 0:
+            print(f"Finding available camera indices through scanning all indices from 0 to {MAX_OPENCV_INDEX}")
+            camera_ids = find_camera_indices()
 
     print("Connecting cameras")
     cameras = []
@@ -76,7 +99,7 @@ def save_images_from_cameras(
         cameras.append(camera)
 
     images_dir = Path(
-        images_dir,
+        images_dir
     )
     if images_dir.exists():
         shutil.rmtree(
@@ -99,7 +122,7 @@ def save_images_from_cameras(
                 executor.submit(
                     save_image,
                     image,
-                    camera.camera_index,
+                    camera.camera_index_to_int(),
                     frame_index,
                     images_dir,
                 )
@@ -200,6 +223,11 @@ class OpenCVCamera:
         self.stop_event = None
         self.color_image = None
         self.logs = {}
+    
+    def camera_index_to_int(self):
+        if isinstance(self.camera_index, int):
+            return self.camera_index
+        return int(self.camera_index.replace("/dev/video", ""))
 
     def connect(self):
         if self.is_connected:
@@ -216,7 +244,9 @@ class OpenCVCamera:
         # valid cameras.
         if not is_camera_open:
             # Verify that the provided `camera_index` is valid before printing the traceback
-            available_cam_ids = find_camera_indices()
+            available_cam_ids = find_camera_ports()
+            if len(available_cam_ids) == 0:
+                available_cam_ids = find_camera_indices()
             if self.camera_index not in available_cam_ids:
                 raise ValueError(
                     f"`camera_index` is expected to be one of these available cameras {available_cam_ids}, but {self.camera_index} is provided instead."
@@ -360,7 +390,7 @@ if __name__ == "__main__":
     )
     parser.add_argument(
         "--camera-ids",
-        type=int,
+        type=str,
         nargs="*",
         default=None,
         help="List of camera indices used to instantiate the `OpenCVCamera`. If not provided, find and use all available camera indices.",