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Diffstat (limited to 'libjava/classpath/gnu/javax/sound/midi/file/MidiFileWriter.java')
| -rw-r--r-- | libjava/classpath/gnu/javax/sound/midi/file/MidiFileWriter.java | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/javax/sound/midi/file/MidiFileWriter.java b/libjava/classpath/gnu/javax/sound/midi/file/MidiFileWriter.java new file mode 100644 index 000000000..5170fc1e7 --- /dev/null +++ b/libjava/classpath/gnu/javax/sound/midi/file/MidiFileWriter.java @@ -0,0 +1,197 @@ +/* MidiFileWriter.java -- Write MIDI files. + Copyright (C) 2006 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package gnu.javax.sound.midi.file; + +import java.io.File; +import java.io.FileOutputStream; +import java.io.IOException; +import java.io.OutputStream; + +import javax.sound.midi.MetaMessage; +import javax.sound.midi.MidiEvent; +import javax.sound.midi.Sequence; +import javax.sound.midi.Track; + +/** + * A MIDI file writer. + * + * This code writes MIDI file types 0 and 1. + * + * There are many decent documents on the web describing the MIDI file + * format. I didn't bother looking for the official document. If it + * exists, I'm not even sure if it is freely available. We should + * update this comment if we find out anything helpful here. + * + * @author Anthony Green (green@redhat.com) + * + */ +public class MidiFileWriter + extends javax.sound.midi.spi.MidiFileWriter +{ + /* Return an array indicating which midi file types are supported. + * @see javax.sound.midi.spi.MidiFileWriter#getMidiFileTypes() + */ + public int[] getMidiFileTypes() + { + return new int[]{0, 1}; + } + + /* Return an array indicating which midi file types are supported + * for a given Sequence. + * @see javax.sound.midi.spi.MidiFileWriter#getMidiFileTypes(javax.sound.midi.Sequence) + */ + public int[] getMidiFileTypes(Sequence sequence) + { + if (sequence.getTracks().length == 1) + return new int[]{0}; + else + return new int[]{1}; + } + + /* Write a sequence to an output stream in standard midi format. + * @see javax.sound.midi.spi.MidiFileWriter#write(javax.sound.midi.Sequence, int, java.io.OutputStream) + */ + public int write(Sequence in, int fileType, OutputStream out) + throws IOException + { + MidiDataOutputStream dos = new MidiDataOutputStream (out); + Track[] tracks = in.getTracks(); + dos.writeInt(0x4d546864); // MThd + dos.writeInt(6); + dos.writeShort(fileType); + dos.writeShort(tracks.length); + float divisionType = in.getDivisionType(); + int resolution = in.getResolution(); + // FIXME: division computation is incomplete. + int division = 0; + if (divisionType == Sequence.PPQ) + division = resolution & 0x7fff; + dos.writeShort(division); + int length = 14; + for (int i = 0; i < tracks.length; i++) + length += writeTrack(tracks[i], dos); + return length; + } + + /** + * Compute the length of a track as it will be written to the + * output stream. + * + * @param track the track to measure + * @param dos a MidiDataOutputStream used for helper method + * @return the length of the track + */ + private int computeTrackLength(Track track, MidiDataOutputStream dos) + { + int count = 0, length = 0, i = 0, eventCount = track.size(); + long ptick = 0; + while (i < eventCount) + { + MidiEvent me = track.get(i); + long tick = me.getTick(); + length += dos.variableLengthIntLength((int) (tick - ptick)); + ptick = tick; + length += me.getMessage().getLength(); + i++; + } + return length; + } + + /** + * Write a track to an output stream. + * + * @param track the track to write + * @param dos a MidiDataOutputStream to write to + * @return the number of bytes written + */ + private int writeTrack(Track track, MidiDataOutputStream dos) + throws IOException + { + int i = 0, elength = track.size(), trackLength; + MidiEvent pme = null; + dos.writeInt(0x4d54726b); // "MTrk" + trackLength = computeTrackLength(track, dos); + dos.writeInt(trackLength); + while (i < elength) + { + MidiEvent me = track.get(i); + int dtime = 0; + if (pme != null) + dtime = (int) (me.getTick() - pme.getTick()); + dos.writeVariableLengthInt(dtime); + // FIXME: use running status byte + byte msg[] = me.getMessage().getMessage(); + dos.write(msg); + pme = me; + i++; + } + + // We're done if the last event was an End of Track meta message. + if (pme != null && (pme.getMessage() instanceof MetaMessage)) + { + MetaMessage mm = (MetaMessage) pme.getMessage(); + if (mm.getType() == 0x2f) // End of Track message + return trackLength + 8; + } + + // Write End of Track meta message + dos.writeVariableLengthInt(0); // Delta time of 0 + dos.writeByte(0xff); // Meta Message + dos.writeByte(0x2f); // End of Track message + dos.writeVariableLengthInt(0); // Length of 0 + + return trackLength + 8 + 4; + } + + /* Write a Sequence to a file. + * @see javax.sound.midi.spi.MidiFileWriter#write(javax.sound.midi.Sequence, int, java.io.File) + */ + public int write(Sequence in, int fileType, File out) throws IOException + { + OutputStream os = new FileOutputStream(out); + try + { + return write(in, fileType, os); + } + finally + { + os.close(); + } + } + +} |