Using third-party MIDI source files?

[hardwired]

Hey all,

I am trying to use a third-party MIDI source library and files and I have a few questions on it. I did contact the guy who wrote the source files but have not had a reply and was wondering if someone could quickly answer a few queries on it so i can get it working as soon as i can as my hand-in date is looming fast..
I am trying to use CraigSapp MidiFile from here:
https://github.com/craigsapp/midifile

I am currently writing a C++ console-based application for a music sequencer for my degree and wanted to utilise saving the info to a MIDI file..

Below is the code I adapted from his code at https://github.com/craigsapp/midifile/blob/master/src-programs/createmidifile.cpp

Not included in the code here (and to give you a basic background on the program and any variable shown):
• The user enters note values and duration (in quarter notes or fractions thereof (1 bar, beat, 16th of a bar etc) but is also expressed in milliseconds in another variable which may be easier to use)..
• These note values (C8 or G#7) are converted to MIDI numbers..
• The MIDI numbers are added to an array of vectors (NOTE_MIDINUM[]) – one vector for each track (melody)..
• Likewise for the durations – the ms values are in the vectors NOTE_DURATION_MS..
• NUMBER_OF_MELODIES is simply an integer value for the number of tracks..
• FULL_MIDI_PATH is simply a string value for the path and filename of the .mid file..
• The variable counter i = 0 – counter is a typedef for unsigned ints used in loops..

// FUNCTION: CREATE MIDI DATA..
/* CODE SUPPLIED (BUT EDITED TO SUIT) FROM CRAIGSAPP MIDIFILE: https://github.com/craigsapp/midifile */
void CREATE_MIDI()
{
       MidiFile outputfile;        // CREATE AN EMPTY MIDI FILE WITH ONE TRACK..
       outputfile.absoluteTicks();  // TIME INFO STORED AS ABSOLUTE TIME..
       outputfile.addTrack(NUMBER_OF_MELODIES -1);     // ADD ALL CURRENT MELODIES (-1 AS WE ALREADY HAVE ONE TRACK)..
       vector<uchar> midievent;     // TEMP STORAGE FOR MIDI EVENTS..
       midievent.resize(3);        // SET THE ARRAY SIZE TO 3 BYTES..
       int tpq = 120;              // default value in MIDI file is 48
       outputfile.setTicksPerQuarterNote(tpq);

       // store a melody line in track 1 (track 0 left empty for conductor info)
       int i = 0;
       int actiontime = 0;      // temporary storage for MIDI event time
       midievent[2] = 64;       // store attack/release velocity for note command..

       // FOR: LOOP AROUND NUMBER OF MELODIES..
       for (counter i = 0; i < NUMBER_OF_MELODIES; ++i)
       {
             // FOR: LOOP ROUND NUMBER OF NOTES IN EACH MELODY..
             for (counter j = 0; j < NOTE_MIDINUM[i].size(); ++j)
             {
                    midievent[i] = 0x90;     // STORE 'NOTE-ON' COMMAND (ON MIDI CHANNEL 1)..
                    midievent[i+1] = NOTE_MIDINUM[i][j];    // ADD MELODY MIDI NUMBER INFO..
                    outputfile.addEvent(1, actiontime, midievent); // APPEND THE MIDI EVENT TO THE FILE..
                    actiontime += tpq * NOTE_DURATION_MS[i][j];          // CALCULATE TIMINGS AND APPEND FOR EACH NOTE..         
                    midievent[i] = 0x80;     // STORE 'NOTE-OFF' COMMAND (ON MIDI CHANNEL 1)..
                    outputfile.addEvent(1, actiontime, midievent); // APPEND THE MIDI EVENT TO THE FILE..
                    actiontime = 0;     //RESET ACTIONTIME..
             }
             // END FOR..
       }
       // END FOR..

       outputfile.sortTracks();         // ORGANISE DATA INTO CORRECT ORDER..
       outputfile.write(FULL_MIDI_PATH); // WRITE STANDARD MIDI FILE..
}
// END FUNCTION.. 

The questions are as follows:

1: Firstly, in the original code he shows, he has:

int melody[50] = { 72,72,79,79,81,81,79,77,77,76,76,74,74,72,-1 };
int mrhythm[50] = { 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2,-1 };

I was wondering what does the -1 mean at the end of these arrays and why?
For the mrhythm, what are these values expressed in? What units? Seconds? Quarter notes?
If I wanted to use milliseconds, what would I need to change in the code above?



2: Do I need to include the MIDI file header / command byte etc? Or is the code as above sufficient? In one area he shows how to create the header but in his code example its not there.
If I do, what does the following mean? (from the page http://midifile.sapp.org/class/MidiFile/):

// 1. The characters "MThd"
   ch = 'M'; out << ch;
   ch = 'T'; out << ch;
   ch = 'h'; out << ch;
   ch = 'd'; out << ch;

3: Even though I have all the header files in my program directory, I have only included #include “MidiFile.h” – do I need to include them all?
I did check all the header files and they are include guarded with usual #ifndef macro. When compiling, I get the following errors:

Severity	Code	Description	Project	File	Line
Error	LNK1120	8 unresolved externals	with:

Error	LNK2019	unresolved external symbol "public: int __thiscall MidiFile::addEvent(int,int,class std::vector<unsigned char,class std::allocator<unsigned char> > &)" (?addEvent@MidiFile@@QAEHHHAAV?$vector@EV?$allocator@E@std@@@std@@@Z) referenced in function "void __cdecl CREATE_MIDI(void)" (?CREATE_MIDI@@YAXXZ)	SPMA - Assignment 1 - 4591930 EPM	C:\Users\Paul\Desktop\Uni Stuff - YEAR 2\SOFTWARE PROGRAMMING\Assignments\Assignment 1\SPMA - Assignment 1 - 4591930 EPM\Main.obj	1

Many thanks,

Paul..