create Image From Midi File - Java javax.sound.midi

Java examples for javax.sound.midi:MidiDevice

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Description

create Image From Midi File

Demo Code


//package com.java2s;
import java.awt.*;
import java.awt.image.*;
import java.util.*;
import javax.sound.midi.*;

public class Main {
    public static BufferedImage createImageFromMidiFile(Sequence midi) {
        int width = (int) midi.getTickLength();
        int height = 2 * 128;
        int scale = 1;

        long noteOn = 0, noteOff = 0;

        BufferedImage result = null;

        do {/*from  w  ww  . j av  a2 s.c  o m*/
            try {
                result = new BufferedImage(width, height,
                        BufferedImage.TYPE_INT_RGB);
            } catch (OutOfMemoryError er) {
                width /= 2;
                scale = 1;
                continue;
            }
        } while (result == null);

        System.out.printf("Image size: %dx%d\n", width, height);
        System.out
                .printf("Number of tracks: %d\n", midi.getTracks().length);

        Graphics2D g = (Graphics2D) result.getGraphics();

        // Fill the background with white
        g.setColor(Color.white);
        g.fillRect(0, 0, width, height);

        // For each track, fill in where the notes are being played
        long[] noteList = new long[128];

        Track cur;
        MidiMessage msg;
        ShortMessage noteCmd;
        long oldestTime = 0;
        for (int i = 1; i < midi.getTracks().length; i++) {
            Arrays.fill(noteList, -1);
            oldestTime = 0;

            if (i != 9)
                g.setColor(Color.black);
            else
                g.setColor(Color.red);

            cur = midi.getTracks()[i];
            for (int j = 0; j < cur.size(); j++) {
                msg = cur.get(j).getMessage();
                if (!(msg instanceof ShortMessage))
                    continue;

                noteCmd = (ShortMessage) msg;
                int note = noteCmd.getData1();

                if (noteCmd.getCommand() == ShortMessage.NOTE_ON
                        && noteCmd.getData1() != 0) {
                    noteList[note] = cur.get(j).getTick();
                    noteOn++;

                    drawLine(g, scale * (int) noteList[note], scale
                            * ((int) noteList[note] + 1), note);
                } else if (noteCmd.getCommand() == ShortMessage.NOTE_OFF
                        || (noteCmd.getCommand() == ShortMessage.NOTE_ON && noteCmd
                                .getData1() == 0)) {
                    drawLine(g, scale * (int) noteList[note], scale
                            * (int) cur.get(j).getTick(), note);
                    noteList[note] = -1;
                    noteOff++;
                } else
                    continue;

                if (oldestTime < cur.get(j).getTick())
                    oldestTime = cur.get(j).getTick();
            } // end for each message
        } // end for each track

        result.flush();

        System.out
                .printf("Number of note-on messages: %d\nNumber of note-off messages: %d\n",
                        noteOn, noteOff);

        return result;
    }

    public static void drawLine(Graphics2D g, int start, int end, int y) {
        if (start < 0)
            return;

        g.fillRect(start, y * 2, (end - start + 1), 2);
    }
}

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