Processing 1.0 - Processing Discourse - reading scores out of midi files

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Index › Programming Questions & Help › Sound, Music Libraries › reading scores out of midi files

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reading scores out of midi files (Read 859 times)

pixonaut YaBB Newbies Offline Posts: 18	reading scores out of midi files May 23^rd, 2008, 9:10pm Hi to all, i search a way to read scores out of midi files. Im totally new to the midi field. Can anybody give me a tip what is the best way to make this? thanks beforehand.

antiplastik YaBB Moderator Offline Posts: 699 France	Re: reading scores out of midi files Reply #1 - May 24^th, 2008, 12:08am Midi notes are stored with numbers. 60 is known as 'middle C' (C4) 61 is C# 62 D etc. There is a Processing library which can read MIDI input signals, but I'm not sure it can read MIDI files. Processing > Reference > Librairies > proMidi > Note > getPitch()

pixonaut

Re: reading scores out of midi files
Reply #2 - May 24^th, 2008, 9:32am

I wanted to test the proMidi library, but i got a lot of error messages, already in the examples.

And nowhere i can find a little sketch, where i can see how i can upload an simple midi file.

The next Library i tested arround with was jm-Etude.

Here i can see that a midi file uploaded into processing, but when i wanted to play the music, i also got an error.

Code:


import jmetude.*;

Etude e;
String[] parts;

void setup() {
    size(400,400);
    Etude e = new Etude(this);
    e.createScore("song", "C:/song.mid" );
    String[] parts = e.getScoreParts("song");
}

void draw() {
  
}

void mousePressed() {

  e.stopMIDI();
  e.playMIDI("song");
  
}

And now Im got a little stuck. Is there anywhere a little tutorial with midi and processing, where i can learn the first steps?

matthieu YaBB Newbies Offline Posts: 16	Re: reading scores out of midi files Reply #3 - May 24^th, 2008, 6:57pm It's impossible to upload midi files with promidi 2.0. Try this import javax.sound.midi.*; Sequence sequence = MidiSystem.getSequence(new File("C:/song.mid"));

pixonaut

Re: reading scores out of midi files
Reply #4 - May 25^th, 2008, 10:10am

Becouse in my opinion jm.etude is easyer to understand i going on playing around with it.

And I managed to play a midi song.

Code:



import jmetude.*;

Etude e;
String[] parts;
String[] phrases;
float notes[][]; 


void setup() {

    size(800,200);
    e = new Etude(this);
    e.createScore("title", "C:/song.mid" );
    
    String[] parts = e.getScoreParts("title");
    println("Parts: " + parts.length);
    
    String[] phrases = e.getPartPhrases(parts[0]);
    println("Phrases: " + phrases.length);

    float[][] notes = e.getPhraseNotes(phrases[0]);
    
    println("notes: " + notes.length);
    
    e.createPhrase("phrase");
    e.addPhraseNoteList("phrase", notes);
    
    
    for(int i = 0; i < notes.length; i++)
    {
	println(notes[i][0]);
    }
    
    
}

void draw() {
  
  for(int i = 0; i < notes.length; i++)
    {
	println(notes[i][0]);
    }
  
}

void mousePressed() {
  
  e.stopMIDI();
  e.playMIDI("title");
  
}

But i dont understand one thing.
In the setup void the println command works without any problem. But in the draw void i got a NullPointerException.

Can anybody explain me why?

watz

Re: reading scores out of midi files
Reply #5 - May 25^th, 2008, 9:14pm

The reason is this line in setup():

Code:

float[][] notes = e.getPhraseNotes(phrases[0]);

You are defining "notes" as a local variable, which takes precedence over the global variable with the same name. So when you try to use notes inside draw() you're referring to the global variable, which has not been initialized.

The solution is simple. Use the following instead:

Code:

notes = e.getPhraseNotes(phrases[0]);

That way both draw() and setup() refer to the global variable, which has been properly initialized in setup().

marius watz // unlekker // code & form // Generator.x

pixonaut YaBB Newbies Offline Posts: 18	Re: reading scores out of midi files Reply #6 - May 26^th, 2008, 10:12am Ahh i understand, thx watz.

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