/// <summary>
        /// Creates a new SDP media format for a well known media type. Well known type are those that use
        /// ID's less than 96 and don't require rtpmap or fmtp attributes.
        /// </summary>
        public SDPAudioVideoMediaFormat(SDPWellKnownMediaFormatsEnum knownFormat)
        {
            Kind = AudioVideoWellKnown.WellKnownAudioFormats.ContainsKey(knownFormat) ? SDPMediaTypesEnum.audio :
                   SDPMediaTypesEnum.video;
            ID       = (int)knownFormat;
            Rtpmap   = null;
            Fmtp     = null;
            _isEmpty = false;

            if (Kind == SDPMediaTypesEnum.audio)
            {
                var audioFormat = AudioVideoWellKnown.WellKnownAudioFormats[knownFormat];
                Rtpmap = SetRtpmap(audioFormat.FormatName, audioFormat.RtpClockRate, audioFormat.ChannelCount);
            }
            else
            {
                var videoFormat = AudioVideoWellKnown.WellKnownVideoFormats[knownFormat];
                Rtpmap = SetRtpmap(videoFormat.FormatName, videoFormat.ClockRate, 0);
            }
        }
 /// <summary>
 /// Creates a new video format based on a well known SDP format.
 /// </summary>
 public VideoFormat(SDPWellKnownMediaFormatsEnum wellKnown) :
     this(AudioVideoWellKnown.WellKnownVideoFormats[wellKnown])
 {
 }