v4l2transform: Stop stream before closing the devices.
diff --git a/sys/v4l2/gstv4l2transform.c b/sys/v4l2/gstv4l2transform.c
index 58b45b0..dbcccc0 100644
--- a/sys/v4l2/gstv4l2transform.c
+++ b/sys/v4l2/gstv4l2transform.c
@@ -183,6 +183,8 @@
 
   GST_DEBUG_OBJECT (self, "Closing");
 
+  gst_v4l2_object_stop (self->v4l2output);
+  gst_v4l2_object_stop (self->v4l2capture);
   gst_v4l2_object_close (self->v4l2output);
   gst_v4l2_object_close (self->v4l2capture);
   gst_caps_replace (&self->probed_srccaps, NULL);