 <p>According to <a href="http://msdn.microsoft.com/en-us/library/hh180779%28v=vs.95%29.aspx?ppud=4" rel="nofollow">this</a> article you must set <code>[MediaStreamAttributeKeys.CodecPrivateData]</code></p> <p>in the format that codec is expecting ([START_CODE][SPS][START_CODE][PPS])</p> <pre><code>videoStreamAttributes[MediaStreamAttributeKeys.CodecPrivateData] = "000000012742000D96540A0FD8080F162EA00000000128CE060C88"; </code></pre>