feat(simulator): add simulator source

camera/depthai.py

@@ -199,8 +199,59 @@ class CameraSource(Source):
         return self._xout_rgb.getStreamName()
 
 
+class MqttSource(Source):
+    """Image source based onto mqtt stream"""
+
+    def __init__(self, device: dai.Device, pipeline: dai.Pipeline, mqtt_host: str, mqtt_topic: str,
+                 mqtt_port: int = 1883, mqtt_qos: int = 0):
+        self._mqtt_host = mqtt_host
+        self._mqtt_port = mqtt_port
+
+        self._client = mqtt.Client()
+        self._client.user_data_set({"topic": mqtt_topic, "qos": str(mqtt_qos)})
+        self._client.on_connect = self._on_connect
+        self._client.on_message = self._on_message
+
+        self._img_in = pipeline.createXLinkIn()
+        self._img_in.setStreamName("img_input")
+        self._img_out = pipeline.createXLinkOut()
+        self._img_out.setStreamName("img_output")
+        self._img_in.out.link(self._img_out.input)
+
+        self._img_in_queue = device.getInputQueue(self._img_in.getStreamName())
+
+    def run(self):
+        self._client.connect(host=self._mqtt_host, port=self._mqtt_port)
+        self._client.loop_start()
+
+    def stop(self):
+        self._client.loop_stop()
+        self._client.disconnect()
 
     @staticmethod
+    def _on_connect(client: mqtt.Client, userdata: dict[str, str], flags, rc):
+        # if we lose the connection and reconnect then subscriptions will be renewed.
+        client.subscribe(topic=userdata["topic"], qos=int(userdata["qos"]))
+
+    def _on_message(self, _: mqtt.Client, user_data: dict[str, str], msg: mqtt.MQTTMessage):
+        frame_msg = events.events_pb2.FrameMessage()
+        frame_msg.ParseFromString(msg.payload)
+
+        frame = np.asarray(frame_msg.frame, dtype="uint8")
+        frame = cv2.imdecode(frame, cv2.IMREAD_COLOR)
+        nn_data = dai.NNData()
+        nn_data.setLayer("data", _to_planar(frame, frame.shape()))
+        self._img_in_queue.send(nn_data)
+
+    def get_stream_name(self) -> str:
+        return self._img_out.getStreamName()
+
+    def link_preview(self, input_node: dai.Node.Input):
+        self._img_in.out.link(input_node)
+
+
+def _to_planar(arr: np.ndarray, shape: tuple) -> list:
+    return [val for channel in cv2.resize(arr, shape).transpose(2, 0, 1) for y_col in channel for val in y_col]
 
 
 class PipelineController: