private IPacketTransformer GenerateTransformer(SDPSecurityDescription securityDescription, bool isRtp) { var srtpParams = SrtpParameters.GetSrtpParametersForProfile((int)securityDescription.CryptoSuite); var engine = new SrtpTransformEngine(securityDescription.KeyParams[0].Key, securityDescription.KeyParams[0].Salt, srtpParams.GetSrtpPolicy(), srtpParams.GetSrtcpPolicy()); if (isRtp) { return(engine.GetRTPTransformer()); } else { return(engine.GetRTCPTransformer()); } }