title: gstreamer sample documentation code not running
body: <p>Trying to compile and run a sample appsrc code after having successfully executed several tutorials. This is a documentation code, supposed it to run but ...     </p>
  
  <p>The command used to compile   </p>
  
  <pre><code>gcc appGuideAppSrc.c -o appGuide `pkg-config --cflags --libs gstreamer-0.10 gstreamer-app-0.10`  
  </code></pre>
  
  <p>Got the following error after </p>
  
  <pre><code>appGuideAppSrc.c: In function ‘cb_need_data’:  
  appGuideAppSrc.c:14:8: warning: assignment makes pointer from integer without a cast [enabled by default]  
  appGuideAppSrc.c:18:25: error: lvalue required as left operand of assignment  
  </code></pre>
  
  <p>Ok, the warning is fine but the line where it throws error is which seems to be ok</p>
  
  <pre><code>   GST_BUFFER_PTS (buffer) = timestamp;
  </code></pre>
  
  <p>Based on answer below from @Michal, changed it to TIMESTAMP and got the following error </p>
  
  <pre><code>(appGuide:11043): GLib-GObject-CRITICAL **: g_object_set: assertion `G_IS_OBJECT (object)' failed
  
  (appGuide:11043): GStreamer-CRITICAL **: gst_bin_add_many: assertion `GST_IS_ELEMENT (element_1)' failed  
  
  (appGuide:11043): GStreamer-CRITICAL **: gst_element_link_many: assertion `GST_IS_ELEMENT (element_1)' failed  
  
  (appGuide:11043): GLib-GObject-CRITICAL **: g_object_set: assertion `G_IS_OBJECT (object)' failed  
  
  (appGuide:11043): GLib-GObject-WARNING **: invalid (NULL) pointer instance  
  
  (appGuide:11043): GLib-GObject-CRITICAL **: g_signal_connect_data: assertion  `G_TYPE_CHECK_INSTANCE (instance)' failed  
  </code></pre>
  
  <p>Any inputs ?</p>
  
  <p>References:<br>
  The <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/section-data-spoof.html" rel="nofollow noreferrer">whole appsrc sample code</a></p>