rtp.js

  this.baseServer.on('message', function(msg) {

    var meta = msg.slice(0, 12);
    var sequenceNumber = meta.slice(2, 4).readUInt16BE(0);

    var encryptedAudio = msg.slice(12);
    var decryptedAudio = new Buffer(0);

    for (var i = 0; i < encryptedAudio.length; i += 16) {

      var currentSlice = encryptedAudio.slice(i, i + 16);

      if (currentSlice.length % 16 === 0) {
        var decipher = crypto.createDecipheriv('aes-128-cbc', this.rtspServer.audioAesKey, this.rtspServer.audioAesIv);

        decipher.setAutoPadding(false);
        currentSlice = decipher.update(currentSlice);
      }

      decryptedAudio = Buffer.concat([ decryptedAudio, currentSlice ]);

    }

    console.log(decryptedAudio);
    this.rtspServer.audioProcessor.process(decryptedAudio, sequenceNumber);

  }.bind(this));