r the frame will be stored in it before the first callback is made. If an entire frame is dropped (a 0-byte packet), then no callbacks will be made at all for that frame. </p>
<dl><dt><b>Parameters:</b></dt><dd>
  <table border="0" cellspacing="2" cellpadding="0">
    <tr><td valign="top"></td><td valign="top"><em>_ctx</em>&nbsp;</td><td>An application-provided context pointer. </td></tr>
    <tr><td valign="top"></td><td valign="top"><em>_buf</em>&nbsp;</td><td>The image buffer for the decoded frame. </td>