用 Java 读取 MIDI 文件
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Reading MIDI files in Java
提问by Hassan Khan
I'm trying to read in .MID files to a Java program, and would like to separate each note/chord so as to display them on a UI of some sort. I didn't have much luck using the Sequencer API in Java, and trying to use MidiFileReader directly didn't work for me either. I'll attach the code I used here, if anyone wants to see it:
我正在尝试将 .MID 文件读入 Java 程序，并希望将每个音符/和弦分开，以便在某种 UI 上显示它们。我在 Java 中使用 Sequencer API 时运气不佳，并且尝试直接使用 MidiFileReader 对我也不起作用。我会附上我在这里使用的代码，如果有人想看的话：
package miditest;
import java.io.File;
import java.io.IOException;
import javax.sound.midi.InvalidMidiDataException;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.MidiUnavailableException;
import javax.sound.midi.Sequence;
import javax.sound.midi.Sequencer;
public class Main {
public static void main(String[] args) throws InvalidMidiDataException, IOException, MidiUnavailableException{
Sequence sequence = MidiSystem.getSequence(new File("test.mid"));
// Create a sequencer for the sequence
Sequencer sequencer = MidiSystem.getSequencer();
sequencer.open();
sequencer.setSequence(sequence);
// Start playing
sequencer.start();
}
}
采纳答案by Sami Koivu
I've never looked deeply into the MIDI support in Java, and the last time I played seriously with MIDI programming was when Commodore Amiga was king.
我从来没有深入研究过 Java 中的 MIDI 支持，我最后一次认真对待 MIDI 编程是在 Commodore Amiga 成为王者的时候。
It looks like you may have to do quite a bit of manual work. Here's a crude example that interprets all NOTE_ON and NOTE_OFF events, for the rest of the events it just prints the command number.
看起来您可能需要做相当多的手工工作。这是一个解释所有 NOTE_ON 和 NOTE_OFF 事件的粗略示例，对于其余的事件，它只打印命令编号。
The reason it might seem trickier than one might have thought at first is because MIDI focuses on capturing the instrument events (for example, when a keyboard key was pressed, when it was released, etc), and not on sheet music notation.
它可能看起来比一开始想象的要棘手的原因是因为 MIDI 专注于捕获乐器事件（例如，当按下键盘键时，何时松开等），而不是乐谱记谱法。
This code prints out one line per event, stating with the tick (which is the timing information for the event), channel, event type, note name, key, velocity
此代码为每个事件打印一行，用刻度（这是事件的时间信息）、通道、事件类型、音符名称、键、力度说明
import java.io.File;
import javax.sound.midi.MidiEvent;
import javax.sound.midi.MidiMessage;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Sequence;
import javax.sound.midi.ShortMessage;
import javax.sound.midi.Track;
public class Test {
public static final int NOTE_ON = 0x90;
public static final int NOTE_OFF = 0x80;
public static final String[] NOTE_NAMES = {"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"};
public static void main(String[] args) throws Exception {
Sequence sequence = MidiSystem.getSequence(new File("test.mid"));
int trackNumber = 0;
for (Track track : sequence.getTracks()) {
trackNumber++;
System.out.println("Track " + trackNumber + ": size = " + track.size());
System.out.println();
for (int i=0; i < track.size(); i++) {
MidiEvent event = track.get(i);
System.out.print("@" + event.getTick() + " ");
MidiMessage message = event.getMessage();
if (message instanceof ShortMessage) {
ShortMessage sm = (ShortMessage) message;
System.out.print("Channel: " + sm.getChannel() + " ");
if (sm.getCommand() == NOTE_ON) {
int key = sm.getData1();
int octave = (key / 12)-1;
int note = key % 12;
String noteName = NOTE_NAMES[note];
int velocity = sm.getData2();
System.out.println("Note on, " + noteName + octave + " key=" + key + " velocity: " + velocity);
} else if (sm.getCommand() == NOTE_OFF) {
int key = sm.getData1();
int octave = (key / 12)-1;
int note = key % 12;
String noteName = NOTE_NAMES[note];
int velocity = sm.getData2();
System.out.println("Note off, " + noteName + octave + " key=" + key + " velocity: " + velocity);
} else {
System.out.println("Command:" + sm.getCommand());
}
} else {
System.out.println("Other message: " + message.getClass());
}
}
System.out.println();
}
}
}
For example the fur elise.mid I had lying around here produces something like this at the beginning:
例如，我躺在这里的 fur elise.mid 一开始就产生了这样的东西：
@0 Channel: 1 Note on, E5 key=76 velocity: 127
@192 Channel: 1 Note off, E5 key=76 velocity: 64
@192 Channel: 1 Note on, D#5 key=75 velocity: 127
@384 Channel: 1 Note off, D#5 key=75 velocity: 64
@384 Channel: 1 Note on, E5 key=76 velocity: 127
@576 Channel: 1 Note off, E5 key=76 velocity: 64
@576 Channel: 1 Note on, D#5 key=75 velocity: 127
@768 Channel: 1 Note off, D#5 key=75 velocity: 64
@768 Channel: 1 Note on, E5 key=76 velocity: 127
@960 Channel: 1 Note off, E5 key=76 velocity: 64
@960 Channel: 1 Note on, B4 key=71 velocity: 127
@1152 Channel: 1 Note off, B4 key=71 velocity: 64
@1152 Channel: 1 Note on, D5 key=74 velocity: 127
@1344 Channel: 1 Note off, D5 key=74 velocity: 64
@1344 Channel: 1 Note on, C5 key=72 velocity: 127
@1536 Channel: 1 Note off, C5 key=72 velocity: 64
@1536 Channel: 1 Note on, A4 key=69 velocity: 127
@1920 Channel: 1 Note off, A4 key=69 velocity: 64
UPDATE: The channels are the 16 channels of the MIDI specification.
更新：通道是 MIDI 规范的 16 个通道。
http://www.midi.org/techspecs/gm.php
http://www.midi.org/techspecs/gm.php
Channels: All 16 MIDI Channels are supported. Each Channel can play a variable number of voices (polyphony). Each Channel can play a different instrument (sound/patch/timbre). Key-based percussion is always on MIDI Channel 10.
通道：支持所有 16 个 MIDI 通道。每个通道可以播放可变数量的声音（复音）。每个通道可以播放不同的乐器（声音/音色/音色）。基于键的打击乐始终在 MIDI 通道 10 上。
And velocity is one of the attributes used to control the sounds. For example, capturing MIDI data on a keyboard it'd be the force with which you press a key. Normally it controls the volume of the sound. See here for more details: http://audio.tutsplus.com/tutorials/production/7-ways-to-use-and-edit-midi-velocity/
速度是用于控制声音的属性之一。例如，在键盘上捕捉 MIDI 数据就是你按下一个键的力度。通常它控制声音的音量。有关更多详细信息，请参见此处：http: //audio.tutsplus.com/tutorials/production/7-ways-to-use-and-edit-midi-velocity/
