Java Tutorial/Development/MIDI Sound

Материал из Java эксперт
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Determine the duration of a Midi audio file

import java.io.File;
import java.net.URL;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Sequence;
import javax.sound.midi.Sequencer;
public class Main {
  public static void main(String[] argv) throws Exception {
    Sequence sequence = MidiSystem.getSequence(new File("midiaudiofile"));
    sequence = MidiSystem.getSequence(new URL("http://hostname/midiaudiofile"));
    // Create a sequencer for the sequence
    Sequencer sequencer = MidiSystem.getSequencer();
    sequencer.open();
    sequencer.setSequence(sequence);
    double durationInSecs = sequencer.getMicrosecondLength() / 1000000.0;
  }
}





Determining the File Format of a Midi Audio File

import java.io.File;
import java.net.URL;
import javax.sound.midi.MidiFileFormat;
import javax.sound.midi.MidiSystem;
public class Main {
  public static void main(String[] argv) throws Exception {
    // From file
    MidiFileFormat fformat = MidiSystem.getMidiFileFormat(new File("midifile"));
    // From URL
 //   fformat = MidiSystem.getMidiFileFormat(new URL("http://hostname/midifile"));
    // Get file format
    switch (fformat.getType()) {
    case 0:
      // mid
      break;
    case 1:
      // rmf
      break;
    }
  }
}





Determining When a Midi Audio Player Has Finished Playing

import javax.sound.midi.MetaEventListener;
import javax.sound.midi.MetaMessage;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Sequencer;
public class Main {
  public static void main(String[] argv) throws Exception {
    Sequencer sequencer = MidiSystem.getSequencer();
    sequencer.open();
    sequencer.addMetaEventListener(new MetaEventListener() {
      public void meta(MetaMessage event) {
        if (event.getType() == 47) {
          // Sequencer is done playing
        }
      }
    });
  }
}





Load and play Midi audio

import java.io.File;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Sequence;
import javax.sound.midi.Sequencer;
public class Main {
  public static void main(String[] argv) throws Exception {
    // From file
    Sequence sequence = MidiSystem.getSequence(new File("midiaudiofile"));
    // From URL
    // sequence = MidiSystem.getSequence(new
    // URL("http://hostname/midiaudiofile"));
    // Create a sequencer for the sequence
    Sequencer sequencer = MidiSystem.getSequencer();
    sequencer.open();
    sequencer.setSequence(sequence);
    // Start playing
    sequencer.start();
  }
}





Loading and Playing Midi Audio

import java.io.File;
import java.net.URL;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Sequence;
import javax.sound.midi.Sequencer;
public class Main {
  public static void main(String[] argv) throws Exception {
    Sequence sequence = MidiSystem.getSequence(new File("midifile"));
    // From URL
    sequence = MidiSystem.getSequence(new URL("http://hostname/midifile"));
    // Create a sequencer for the sequence
    Sequencer sequencer = MidiSystem.getSequencer();
    sequencer.open();
    sequencer.setSequence(sequence);
    // Start playing
    sequencer.start();
  }
}





Play a streaming Midi audio

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.URL;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Sequencer;
public class Main {
  public static void main(String[] argv) throws Exception {
    Sequencer sequencer = MidiSystem.getSequencer();
    sequencer.open();
    // From file
    InputStream input = new BufferedInputStream(new FileInputStream(new File("midiaudiofile")));
    // From URL
    input = new BufferedInputStream(new URL("http://hostname/rmffile").openStream());
    sequencer.setSequence(input);
    // Start playing
    sequencer.start();
  }
}





Playing Streaming Midi Audio

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.URL;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Sequencer;
public class Main {
  public static void main(String[] argv) throws Exception {
    Sequencer sequencer = MidiSystem.getSequencer();
    sequencer.open();
    // From file
    InputStream is = new BufferedInputStream(new FileInputStream(new File(
        "midifile")));
    // From URL
//    is = new BufferedInputStream(new URL("http://hostname/rmffile")
  //      .openStream());
    sequencer.setSequence(is);
    // Start playing
    sequencer.start();
  }
}





Setting the Volume of Playing Midi Audio

import javax.sound.midi.MidiChannel;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Sequencer;
import javax.sound.midi.Synthesizer;
public class Main {
  public static void main(String[] argv) throws Exception {
    Sequencer sequencer = MidiSystem.getSequencer();
    sequencer.open();
    if (sequencer instanceof Synthesizer) {
      Synthesizer synthesizer = (Synthesizer) sequencer;
      MidiChannel[] channels = synthesizer.getChannels();
      // gain is a value between 0 and 1 (loudest)
      double gain = 0.9D;
      for (int i = 0; i < channels.length; i++) {
        channels[i].controlChange(7, (int) (gain * 127.0));
      }
    }
  }
}