Add OpenCV driver for camera logging

config/test-opencv-camera.json

@@ -0,0 +1,16 @@
+{
+  "version": 2,
+  "robot": {
+    "modules": {
+      "camera": {
+          "driver": "osgar.drivers.opencv:LogOpenCVCamera",
+          "in": [],
+          "out": ["raw"],
+          "init": {
+              "port": 0
+          }
+      }
+    },
+    "links": []
+  }
+}

osgar/drivers/opencv.py

@@ -0,0 +1,39 @@
+"""
+  Log video stream provided by OpenCV camera
+"""
+
+import cv2
+from threading import Thread
+
+from osgar.logger import LogWriter
+from osgar.bus import BusShutdownException
+
+
+class LogOpenCVCamera:
+    def __init__(self, config, bus):
+        self.input_thread = Thread(target=self.run_input, daemon=True)
+        self.bus = bus
+
+        port = config.get('port', 0)
+        self.cap = cv2.VideoCapture(port)
+
+    def start(self):
+        self.input_thread.start()
+
+    def join(self, timeout=None):
+        self.input_thread.join(timeout=timeout)
+
+    def run_input(self):
+        while self.bus.is_alive():
+            # Capture frame-by-frame
+            ret, frame = self.cap.read()
+            if ret:
+                retval, data = cv2.imencode('*.jpeg', frame)
+                if len(data) > 0:
+                    self.bus.publish('raw', data.tobytes())
+        self.cap.release()
+
+    def request_stop(self):
+        self.bus.shutdown()
+
+# vim: expandtab sw=4 ts=4