Add zoom commands

api/zoom.py

@@ -0,0 +1,32 @@
+class ZoomAPIMixin:
+    """
+    API for zooming and changing focus.
+    Note that the API does not allow zooming/focusing by absolute
+    values rather that changing focus/zoom for a given time.
+    """
+    def _start_zoom(self, direction, speed=60):
+        op = 'ZoomInc' if direction == 'in' else 'ZoomDec'
+        data = [{"cmd": "PtzCtrl", "action": 0, "param": {"channel": 0, "op": op, "speed": speed}}]
+        return self._execute_command('PtzCtrl', data)
+
+    def start_zoom_in(self, speed=60):
+        """
+        The camera zooms in until self.stop_zoom() is called.
+        :return: response json
+        """
+        return self._start_zoom('in', speed=speed)
+
+    def start_zoom_out(self, speed=60):
+        """
+        The camera zooms out until self.stop_zoom() is called.
+        :return: response json
+        """
+        return self._start_zoom('out', speed=speed)
+
+    def stop_zoom(self):
+        """
+        Stop zooming.
+        :return: response json
+        """
+        data = [{"cmd": "PtzCtrl", "action": 0, "param": {"channel": 0, "op": "Stop"}}]
+        return self._execute_command('PtzCtrl', data)