assffmpegkit_1_1_session.html">Session</a> has either SessionStateCompleted or SessionStateFailed state when the callback is invoked. </p>
<p>If it has SessionStateCompleted state, <code><a class="el" href="../../d4/dcf/classffmpegkit_1_1_return_code.html">ReturnCode</a></code> should be checked to see the execution result. </p>
<p>If <code>getState</code> returns SessionStateFailed then <code>getFailStackTrace</code> should be used to get the failure reason. </p><pre>
 switch (session-&gt;getState()) {
   