MidiSheetMusic.MidiFile.parse C# (CSharp) Method

        public void parse(MidiFileReader file, string filename)
        {
            string id;
            int len;

            this.filename = filename;
            tracks = new List<MidiTrack>();
            trackPerChannel = false;

            id = file.ReadAscii(4);
            if (id != "MThd") {
            throw new MidiFileException("Doesn't start with MThd", 0);
            }
            len = file.ReadInt();
            if (len !=  6) {
            throw new MidiFileException("Bad MThd header", 4);
            }
            trackmode = file.ReadShort();
            int num_tracks = file.ReadShort();
            quarternote = file.ReadShort();

            events = new List<MidiEvent>[num_tracks];
            for (int tracknum = 0; tracknum < num_tracks; tracknum++) {
            events[tracknum] = ReadTrack(file);
            MidiTrack track = new MidiTrack(events[tracknum], tracknum);
            if (track.Notes.Count > 0) {
                tracks.Add(track);
            }
            }

            /* Get the length of the song in pulses */
            foreach (MidiTrack track in tracks) {
            MidiNote last = track.Notes[track.Notes.Count-1];
            if (this.totalpulses < last.StartTime + last.Duration) {
                this.totalpulses = last.StartTime + last.Duration;
            }
            }

            /* If we only have one track with multiple channels, then treat
             * each channel as a separate track.
             */
            if (tracks.Count == 1 && HasMultipleChannels(tracks[0])) {
            tracks = SplitChannels(tracks[0], events[tracks[0].Number]);
            trackPerChannel = true;
            }

            CheckStartTimes(tracks);

            /* Determine the time signature */
            int tempo = 0;
            int numer = 0;
            int denom = 0;
            foreach (List<MidiEvent> list in events) {
            foreach (MidiEvent mevent in list) {
                if (mevent.Metaevent == MetaEventTempo && tempo == 0) {
                    tempo = mevent.Tempo;
                }
                if (mevent.Metaevent == MetaEventTimeSignature && numer == 0) {
                    numer = mevent.Numerator;
                    denom = mevent.Denominator;
                }
            }
            }
            if (tempo == 0) {
            tempo = 500000; /* 500,000 microseconds = 0.05 sec */
            }
            if (numer == 0) {
            numer = 4; denom = 4;
            }
            timesig = new TimeSignature(numer, denom, quarternote, tempo);
        }