FFMpeg Playback

private void DoStart()
        {
            var vss = Source;
            if (!_modeAudio)
                vss = Tokenise(vss);

            AVDictionary* options = null;
            if (_inputFormat == null)
            {
                ffmpeg.av_dict_set(&options, "analyzeduration", _analyzeDuration.ToString(), 0);



                string prefix = vss.ToLower().Substring(0, vss.IndexOf(":", StringComparison.Ordinal));
                switch (prefix)
                {
                    case "http":
                    case "mmsh":
                    case "mms":
                        ffmpeg.av_dict_set(&options, "timeout", _timeout.ToString(CultureInfo.InvariantCulture), 0);
                        ffmpeg.av_dict_set(&options, "stimeout", (_timeout * 1000).ToString(CultureInfo.InvariantCulture), 0);

                        if (_cookies != "")
                        {
                            ffmpeg.av_dict_set(&options, "cookies", _cookies, 0);
                        }

                        if (_headers != "")
                        {
                            ffmpeg.av_dict_set(&options, "headers", _headers, 0);
                        }
                        if (_userAgent != "")
                        {
                            ffmpeg.av_dict_set(&options, "user-agent", _userAgent, 0);
                        }
                        break;
                    case "tcp":
                    case "udp":
                    case "rtp":
                    case "sdp":
                    case "mmst":
                    case "ftp":
                        ffmpeg.av_dict_set(&options, "timeout", _timeout.ToString(CultureInfo.InvariantCulture), 0);
                        break;
                    case "rtsp":
                    case "rtmp":
                        ffmpeg.av_dict_set(&options, "stimeout", (_timeout * 1000).ToString(CultureInfo.InvariantCulture), 0);
                        if (_userAgent != "")
                        {
                            ffmpeg.av_dict_set(&options, "user-agent", _userAgent, 0);
                        }
                        break;
                }

                ffmpeg.av_dict_set(&options, "rtsp_transport", _rtsPmode, 0);
            }

            ffmpeg.av_dict_set(&options, "rtbufsize", "10000000", 0);

            var lo = _options.Split(Environment.NewLine.ToCharArray());
            foreach (var nv in lo)
            {
                if (!string.IsNullOrEmpty(nv))
                {
                    var i = nv.IndexOf('=');
                    if (i > -1)
                    {
                        var n = nv.Substring(0, i).Trim();
                        var v = nv.Substring(i + 1).Trim();
                        if (!string.IsNullOrEmpty(n) && !string.IsNullOrEmpty(v))
                        {
                            int j;
                            if (int.TryParse(v, out j))
                            {
                                ffmpeg.av_dict_set_int(&options, n, j, 0);
                            }
                            else
                            {
                                ffmpeg.av_dict_set(&options, n, v, 0);
                            }
                        }
                    }
                }
            }


            _stopReadingFrames = false;
            try
            {
                Program.FfmpegMutex.WaitOne();
                var pFormatContext = ffmpeg.avformat_alloc_context();
                _lastPacket = DateTime.UtcNow;


                _interruptCallback = InterruptCb;
                _interruptCallbackAddress = Marshal.GetFunctionPointerForDelegate(_interruptCallback);

                pFormatContext->interrupt_callback.callback = _interruptCallbackAddress;
                pFormatContext->interrupt_callback.opaque = null;


                if (ffmpeg.avformat_open_input(&pFormatContext, vss, _inputFormat, &options) != 0)
                {
                    throw new ApplicationException(@"Could not open source");
                }
                _formatContext = pFormatContext;


                SetupFormat();
            }
            catch (Exception ex)
            {
                ErrorHandler?.Invoke(ex.Message);
                _res = ReasonToFinishPlaying.VideoSourceError;
                PlayingFinished?.Invoke(this, new PlayingFinishedEventArgs(_res));
                AudioFinished?.Invoke(this, new PlayingFinishedEventArgs(_res));

            }
            finally
            {
                try
                {
                    Program.FfmpegMutex.ReleaseMutex();
                }
                catch
                {

                }
            }
            _starting = false;
        }