package net.cscott.sdr.sound;

 /*

  *        Derived from LoopingMidiPlayer15.java, from jsresources.org

  *      Requires JDK1.5 or later.

  */

 /* for our test files, tempo is 120bpm, and resolution is 384 PPQ.  This

  * means that a midi tick is 1/768s, which is more than adequate resolution

  * for (say) 15-30fps animation. */

 import java.io.IOException;

 import java.util.concurrent.BlockingQueue;

 import javax.sound.midi.InvalidMidiDataException;

 import javax.sound.midi.MetaEventListener;

 import javax.sound.midi.MetaMessage;

 import javax.sound.midi.MidiSystem;

 import javax.sound.midi.MidiUnavailableException;

 import javax.sound.midi.Receiver;

 import javax.sound.midi.Sequence;

 import javax.sound.midi.Sequencer;

 import javax.sound.midi.ShortMessage;

 import javax.sound.midi.Soundbank;

 import javax.sound.midi.Synthesizer;

 import javax.sound.midi.Transmitter;

 import net.cscott.sdr.BeatTimer;

 import net.cscott.sdr.anim.SilentBeatTimer;

 public class MidiThread extends Thread

 {

     private final BlockingQueue<BeatTimer> rendezvousBT;

     public MidiThread(BlockingQueue<BeatTimer> rendezvousBT) {

         this.rendezvousBT = rendezvousBT;

     }

     @Override

     public void run() {

         BeatTimer beatTimer;

         try {

             beatTimer = playMidi();

         } catch (Exception e) {

             // no music. =(

             beatTimer = new SilentBeatTimer();

         }

         // send the beat timer to the rest of the system.

         rendezvousBT.add(beatTimer);

     }

     public BeatTimer playMidi() 

     throws MidiUnavailableException, InvalidMidiDataException, IOException

     {

         final Sequencer sequencer;

         final Synthesizer synthesizer;

         /* Use high-quality soundbank. */

         Soundbank soundbank = MidiSystem.getSoundbank

         (MidiThread.class.getClassLoader().getResource

                 ("net/cscott/sdr/sound/soundbank-deluxe.gm"));

         //soundbank=null;

         /* We read in the MIDI file to a Sequence object.  This object

          * is set at the Sequencer later.

          */

         Sequence sequence = MidiSystem.getSequence

         (MidiThread.class.getClassLoader().getResource

                 ("net/cscott/sdr/sound/saturday-night.midi"));

         // print out some info about timing resolution.

         System.out.println("Division type: "+sequence.getDivisionType());

         System.out.println("Resolution: "+sequence.getResolution());

         assert sequence.getDivisionType()==Sequence.PPQ :

             "don't know how to sync non-PPQ tracks";

         @SuppressWarnings("unused") int ticksPerBeat = sequence.getResolution();

         /* Now, we need a Sequencer to play the sequence.  Here, we

          * simply request the default sequencer without an implicitly

          * connected synthesizer

          */

         sequencer = MidiSystem.getSequencer(false);

         /* The Sequencer is still a dead object.  We have to open() it

          * to become live.  This is necessary to allocate some

          * ressources in the native part.

          */

         sequencer.open();

         /* Next step is to tell the Sequencer which Sequence it has to

          * play. In this case, we set it as the Sequence object

          * created above.

          */

         sequencer.setSequence(sequence);

         // XXX: at this point, it would be safe to create/return the BeatTimer

         // Mississippi Sawyer is *half note*=120; Java doesn't seem to grok

         // this.  Something like the following is needed for these cases:

         // sequencer.setTempoFactor(2f);

         /* We try to get the default synthesizer, open() it and chain

          * it to the sequencer with a Transmitter-Receiver pair.

          */

         synthesizer = MidiSystem.getSynthesizer();

         synthesizer.open();

         boolean loaded = false;

         if (soundbank!=null)

             loaded = synthesizer.loadAllInstruments(soundbank);

         System.out.println("Instruments "+(loaded?"":"not ")+"loaded.");

         Receiver        synthReceiver = synthesizer.getReceiver();

         Transmitter        seqTransmitter = sequencer.getTransmitter();

         seqTransmitter.setReceiver(synthReceiver);

         /* To free system resources, it is recommended to close the

          * synthesizer and sequencer properly.

          *

          * To accomplish this, we register a Listener to the

          * Sequencer. It is called when there are "meta" events. Meta

          * event 47 is end of track.

          *

          * Thanks to Espen Riskedal for finding this trick.

          */

         sequencer.addMetaEventListener(new MetaEventListener()

                 {

             public void meta(MetaMessage event)

             {

                 if (event.getType() == 47)

                 {

                     sequencer.close();

                     if (synthesizer != null)

                     {

                         synthesizer.close();

                     }

                     //System.exit(0);

                 }

             }

                 });

         /* Here, we set the loop points to loop over the whole

          * sequence. Setting the loop end point to -1 means using the

          * last tick of the sequence as end point of the loop.

          *

          * Furthermore, we set the number of loops to loop infinitely.

          */

         sequencer.setLoopStartPoint(0);

         sequencer.setLoopEndPoint(-1);

         sequencer.setLoopCount(Sequencer.LOOP_CONTINUOUSLY);

         /* WORKAROUND for BUG in jdk 1.6 (at least): loop control has an

          * off-by-one error and doesn't play the (usually note off) messages

          * in the last tick of the song; it just jumps to tick 0 and plays

          * the note-on messages there.  Workaround this by manually kludging

          * in ALL_NOTE_OFF messages on all channels one tick before the end

          * of the song.  Sigh. */

         for (int i=0; i<16; i++) {

             javax.sound.midi.ShortMessage notesOff =

                 new javax.sound.midi.ShortMessage();

             notesOff.setMessage(ShortMessage.CONTROL_CHANGE+i,123,0);

             for (javax.sound.midi.Track t : sequence.getTracks()) {

                 long end = (t.ticks()<=0)?0L:(t.ticks()-1);

                 t.add(new javax.sound.midi.MidiEvent(notesOff, end));

             }

         }

         /* Ok, play the music!

          */

         sequencer.start();

         return new MidiTimer(sequencer);

     }

 }