title: Is it possible to do a simple health check of RTSP stream with curl tool?
body: <p>I'm trying to do a simple health check of RTSP stream with curl tool.<br>
  But command like this always gives me 404 Stream Not Found error:  </p>
  
  <pre><code>curl -v --url rtsp://192.168.1.80/h264/ --user admin:1234
  *   Trying 192.168.1.80...
  * Connected to 192.168.1.80 (192.168.1.80) port 554 (#0)
  * Server auth using Basic with user 'admin'
  &gt; OPTIONS * RTSP/1.0
  &gt; CSeq: 1
  &gt; User-Agent: curl/7.47.0
  &gt; Authorization: Basic YWRtaW46YWRtaW4=
  &gt; 
  &lt; RTSP/1.0 404 Stream Not Found
  &lt; CSeq: 1
  &lt; Date: Tue, Feb 27 2018 01:14:21 GMT
  &lt; 
  * Connection #0 to host 192.168.1.80 left intact  
  </code></pre>
  
  <p>It looks like that instead of <code>*</code> it should be an URL after <code>OPTIONS</code> here:
  <code>&gt; OPTIONS * RTSP/1.0</code></p>
  
  <p>For instance, I tested the same URI with VLC media player and captured packets with tcpdump. With VLC it works without any issues and data send in request to RTSP server looks like this:</p>
  
  <pre><code>OPTIONS rtsp://192.168.1.80:554/h264 RTSP/1.0
  CSeq: 2
  User-Agent: LibVLC/2.2.2 (LIVE555 Streaming Media v2016.02.09)
  </code></pre>
  
  <p>It looks that there is an option <code>CURLOPT_RTSP_STREAM_URI</code> in libcurl that works under the hood of curl tool, but I can't find command line option to set this parameter so <code>*</code> is used as default value according to this: <a href="https://curl.haxx.se/libcurl/c/CURLOPT_RTSP_STREAM_URI.html" rel="noreferrer">https://curl.haxx.se/libcurl/c/CURLOPT_RTSP_STREAM_URI.html</a>
  And it doesn't automatically use value of --url neither. </p>
  
  <p>Is there a way to test(a simple OK response to DESCRIBE or OPTIONS would be enough I think) RTSP stream with curl tool?</p>