title: Invalid roslaunch XML syntax: not well-formed
body: <p>I am having an error while trying to run video_file.launch, the file contains the following:</p>
  
  <pre><code>&lt;?xml version="1.0"?&gt;
  &lt;launch&gt;
     &lt;!-- launch video stream --&gt;
     &lt;include file="$(find video_stream_opencv)/launch/camera.launch" &gt;
          &lt;!-- node name and ros graph name --&gt;
          &lt;arg name="camera_name" value="videofile" /&gt;
          &lt;!-- full path to the video file --&gt;
          &lt;!-- wget http://techslides.com/demos/sample-videos/small.mp4 -O /tmp/small.mp4 --&gt;
          &lt;arg name="video_stream_provider" value="/tmp/small.mp4" /&gt;
          &lt;!-- set camera fps to (video files not affected) --&gt;
          &lt;!-- &lt;arg name="set_camera_fps" value="30"/&gt; --&gt;
          &lt;!-- set buffer queue size of frame capturing to --&gt;
          &lt;arg name="buffer_queue_size" value="1000" /&gt;
          &lt;!-- throttling the querying of frames to --&gt;
          &lt;arg name="fps" value="30" /&gt;
          &lt;!-- setting frame_id --&gt;
          &lt;arg name="frame_id" value="videofile_frame" /&gt;
          &lt;!-- camera info loading, take care as it needs the "file:///" at the start , e.g.:
          "file:///$(find your_camera_package)/config/your_camera.yaml" --&gt;
          &lt;arg name="camera_info_url" value="" /&gt;
          &lt;!-- flip the image horizontally (mirror it) --&gt;
          &lt;arg name="flip_horizontal" value="false" /&gt;
          &lt;!-- flip the image vertically --&gt;
          &lt;arg name="flip_vertical" value="false" /&gt;
          &lt;!-- enable looping playback --&gt;
          &lt;arg name="loop_videofile" value="true" /&gt;
          &lt;!-- visualize on an image_view window the stream generated --&gt;
          &lt;arg name="visualize" value="true" /&gt;
     &lt;/include&gt;
  &lt;/launch&gt;
  </code></pre>
  
  <p>And this is the error I am getting:</p>
  
  <blockquote>
    <p>Invalid roslaunch XML syntax: not well-formed (invalid token): line 1, column 5</p>
  </blockquote>
  
  <p>The code is the same as found in :</p>
  
  <blockquote>
    <p><a href="https://github.com/ros-drivers/video_stream_opencv" rel="nofollow noreferrer">https://github.com/ros-drivers/video_stream_opencv</a></p>
  </blockquote>