Hardware API redesign (#777)

Co-authored-by: Pepijn <138571049+pkooij@users.noreply.github.com>
Co-authored-by: Steven Palma <imstevenpmwork@ieee.org>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Steven Palma <steven.palma@huggingface.co>
Co-authored-by: Adil Zouitine <adilzouitinegm@gmail.com>
Co-authored-by: Pepijn <pepijn@huggingface.co>

lerobot/common/cameras/camera.py

@@ -0,0 +1,120 @@
+#!/usr/bin/env python
+
+# Copyright 2024 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import abc
+from typing import Any, Dict, List
+
+import numpy as np
+
+from .configs import CameraConfig, ColorMode
+
+
+class Camera(abc.ABC):
+    """Base class for camera implementations.
+
+    Defines a standard interface for camera operations across different backends.
+    Subclasses must implement all abstract methods.
+
+    Manages basic camera properties (FPS, resolution) and core operations:
+    - Connection/disconnection
+    - Frame capture (sync/async)
+
+    Attributes:
+        fps (int | None): Configured frames per second
+        width (int | None): Frame width in pixels
+        height (int | None): Frame height in pixels
+
+    Example:
+        class MyCamera(Camera):
+            def __init__(self, config): ...
+            @property
+            def is_connected(self) -> bool: ...
+            def connect(self, warmup=True): ...
+            # Plus other required methods
+    """
+
+    def __init__(self, config: CameraConfig):
+        """Initialize the camera with the given configuration.
+
+        Args:
+            config: Camera configuration containing FPS and resolution.
+        """
+        self.fps: int | None = config.fps
+        self.width: int | None = config.width
+        self.height: int | None = config.height
+
+    @property
+    @abc.abstractmethod
+    def is_connected(self) -> bool:
+        """Check if the camera is currently connected.
+
+        Returns:
+            bool: True if the camera is connected and ready to capture frames,
+                  False otherwise.
+        """
+        pass
+
+    @staticmethod
+    @abc.abstractmethod
+    def find_cameras() -> List[Dict[str, Any]]:
+        """Detects available cameras connected to the system.
+        Returns:
+            List[Dict[str, Any]]: A list of dictionaries,
+            where each dictionary contains information about a detected camera.
+        """
+        pass
+
+    @abc.abstractmethod
+    def connect(self, warmup: bool = True) -> None:
+        """Establish connection to the camera.
+
+        Args:
+            warmup: If True (default), captures a warmup frame before returning. Useful
+                   for cameras that require time to adjust capture settings.
+                   If False, skips the warmup frame.
+        """
+        pass
+
+    @abc.abstractmethod
+    def read(self, color_mode: ColorMode | None = None) -> np.ndarray:
+        """Capture and return a single frame from the camera.
+
+        Args:
+            color_mode: Desired color mode for the output frame. If None,
+                        uses the camera's default color mode.
+
+        Returns:
+            np.ndarray: Captured frame as a numpy array.
+        """
+        pass
+
+    @abc.abstractmethod
+    def async_read(self, timeout_ms: float = ...) -> np.ndarray:
+        """Asynchronously capture and return a single frame from the camera.
+
+        Args:
+            timeout_ms: Maximum time to wait for a frame in milliseconds.
+                        Defaults to implementation-specific timeout.
+
+        Returns:
+            np.ndarray: Captured frame as a numpy array.
+        """
+        pass
+
+    @abc.abstractmethod
+    def disconnect(self) -> None:
+        """Disconnect from the camera and release resources."""
+        pass