Java midi播放质量不一致
我最近在开发的游戏中玩MIDI时遇到了一个奇怪的错误。我认为我的midi代码工作得很好，因为它过去播放midi时听起来并不奇怪。现在，每当它播放MIDI时，它们的声音都很小，回声很强，声音也很大 我已经很长时间没有接触我的midi播放器代码了，所以我想知道最近的Java更新是否可能暴露了我代码中一直存在的错误。或者在我的Java版本中可能存在某种我不知道的midi错误 每当我在游戏之外玩MIDI时，它的声音都很好 我正在运行Java6，更新31，构建1.6.0_31-b05。下面是一个重现问题的SSCE（它至少在我的JVM上重现了问题）：Java midi播放质量不一致,java,midi,javasound,Java,Midi,Javasound,我最近在开发的游戏中玩MIDI时遇到了一个奇怪的错误。我认为我的midi代码工作得很好，因为它过去播放midi时听起来并不奇怪。现在，每当它播放MIDI时，它们的声音都很小，回声很强，声音也很大 我已经很长时间没有接触我的midi播放器代码了，所以我想知道最近的Java更新是否可能暴露了我代码中一直存在的错误。或者在我的Java版本中可能存在某种我不知道的midi错误 每当我在游戏之外玩MIDI时，它的声音都很好 我正在运行Java6，更新31，构建1.6.0_31-b05。下面是一个重现问题的
import java.awt.*；
导入java.awt.event.*；
导入javax.swing.*；
导入java.io.*；
导入javax.sound.midi.*；
导入java.net.URL；
公共类MidiSSCCE扩展JFrame
{
公共MidiSSCCE（）
{
超级（“声音问题SSCCE”）；
这个.setSize（200100）；
//实例化主窗口面板
JPanel screenP=新SSCCEPanel（本）；
添加（screenP）；
//游戏窗口的收尾工作
此.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）；
此.setVisible（true）；
System.out.println（“游戏窗口成功创建！！！”；
}
公共静态void main（字符串[]args）
{
MidiSSCCE gui=新的MidiSSCCE（）；
}
}
/**
*SSCCEPanel是管理示例计时器、绘制和逻辑的JPanel。
**/
类SSCCEPanel扩展了JPanel
{
公共框架父框架；
私人定时器；
公共int逻辑循环；
公共双prevFPS；
布尔时差；
//示例使用MidiPlayer对象来播放midi。
公共MIDI播放器；
公共SSCCEPanel（帧父级）
{
超级（真）；
父帧=父帧；
此参数为.setFocusable（true）；
getDefaultToolkit（）.sync（）；
逻辑循环=0；
midiPlayer=新的midiPlayer（）；
TimerListener TimerListener=新TimerListener（）；
prevFPS=0；
timerReady=true；
计时器=新计时器（0，timerListener）；
这是setFPS（60）；
timer.start（）；
}
/**
*setFPS（）
*前提条件：fps是每秒的帧数
*后置条件：设置计时器的刷新率，以便
*每秒发射fps次。
**/
公共无效设置fps（整数fps）
{
int-mspf=（int）（1000.0/fps+0.5）；
定时器设置延迟（mspf）；
}
/**
*这是JPanel的计时器侦听器。它运行示例的逻辑并重新绘制
*方法每次获取计时器信号时。
**/
私有类TimerListener实现ActionListener
{
long startTime=System.currentTimeMillis（）；
long lastTime=this.startTime；
int ticks=0；
已执行的公共无效操作（操作事件e）
{
对象源=e.getSource（）；
如果（源==计时器）
{
//通过游戏逻辑执行循环并重新绘制。
已同步（此）
{
if（timerReady）
{
timerReady=false；
runSSCCELogic（）；
重新油漆（）；
timerReady=true；
}
}
//每秒帧数计数器的逻辑
这个.ticks++；
长currentTime=System.currentTimeMillis（）；
如果（当前时间-开始时间>=500）
{
prevFPS=1000.0*滴答声/（1.0*当前时间-开始时间）；
系统输出打印项次（prevFPS）；
开始时间=当前时间；
滴答声=0；
}
lastTime=当前时间；
}
}
}
/**
*重新绘制SSCCE。
*这只是显示当前FPS。
**/
公共组件（图形g）
{
超级组件（g）；
Graphics2D g2D=（Graphics2D）g；
双舍入fps=数学舍入（prevFPS*10）/10.0；
g2D.setColor（新颜色（0x000000））；
g2D.抽绳（FPS:+roundedFPS，20,20）；
g、 处置（）；
}
/**
*runssceelogic（）
*这就是SSCCE示例的运行时逻辑所在。
*它所做的只是加载和播放一个名为“mymidi.mid”的midi，它位于同一个目录中。
**/
public void runSSCCELogic（）
{
if（logicLoops==1）
{
midiPlayer.load（“http://www.vgmusic.com/music/computer/microsoft/windows/touhou_6_stage3_boss.mid");
midiPlayer.play（真）；
}
逻辑循环++；
}
}
/**
*MIDI播放器
*允许加载和播放midi文件的类。
**/
类MIDI播放器
{
私有序列seq；
专用序列器；
专用合成器合成器；
专用接收机；
私有文件；
私有字符串MIDID；
私有布尔加载；
私有布尔使用硬件undbank；
//建设者
公共MIDI播放器（）
{
加载=错误；
尝试
{
seqr=MidiSystem.getSequencer（）；
synth=MidiSystem.getSynthesizer（）；
}
捕获（例外e）
{
System.out.println（“MIDI错误：您的系统似乎没有MIDI设备或设备不工作。”）；
}
}
/**
*MidiPlayer（字符串文件名）
*构造函数，该构造函数还加载初始midi文件。
*前提条件：fileName是要加载的midi文件的名称。
*后置条件：midi播放器是用文件名指定的midi创建和加载的。
**/
公共MIDI播放器（字符串文件名）
{
这个（）；
加载（文件名）；
}
//数据方法
/**
*l
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import javax.sound.midi.*;
import java.net.URL;
public class MidiSSCCE extends JFrame
{
public MidiSSCCE()
{
super("Sound problem SSCCE");
this.setSize(200,100);
// instantiate main window panel
JPanel screenP = new SSCCEPanel(this);
this.add(screenP);
// finishing touches on Game window
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
System.out.println("Game Window successfully created!!!");
}
public static void main(String[] args)
{
MidiSSCCE gui = new MidiSSCCE();
}
}
/**
* SSCCEPanel is the JPanel that manages the example's timer, painting, and logic.
**/
class SSCCEPanel extends JPanel
{
public Frame parentFrame;
private Timer timer;
public int logicLoops;
public double prevFPS;
boolean timerReady;
// The MidiPlayer object is used by the example to play the midi.
public MidiPlayer midiPlayer;
public SSCCEPanel(Frame parent)
{
super(true);
parentFrame = parent;
this.setFocusable(true);
Toolkit.getDefaultToolkit().sync();
logicLoops = 0;
midiPlayer = new MidiPlayer();
TimerListener timerListener = new TimerListener();
prevFPS = 0;
timerReady = true;
timer = new Timer(0,timerListener);
this.setFPS(60);
timer.start();
}
/**
* setFPS()
* Preconditions: fps is a quantity of frames per second
* Postconditions: Sets the timer's refresh rate so that it
* fires fps times per second.
**/
public void setFPS(int fps)
{
int mspf = (int) (1000.0 /fps + 0.5);
timer.setDelay(mspf);
}
/**
* This is the JPanel's timer listener. It runs the example's logic and repaint
* methods each time it gets a timer signal.
**/
private class TimerListener implements ActionListener
{
long startTime = System.currentTimeMillis();
long lastTime = this.startTime;
int ticks = 0;
public void actionPerformed(ActionEvent e)
{
Object source = e.getSource();
if(source == timer)
{
// perform a loop through the game's logic and repaint.
synchronized(this)
{
if(timerReady)
{
timerReady = false;
runSSCCELogic();
repaint();
timerReady = true;
}
}
// Logic for Frames per Second counter
this.ticks++;
long currentTime = System.currentTimeMillis();
if(currentTime - startTime >= 500)
{
prevFPS = 1000.0 * ticks/(1.0*currentTime - startTime);
System.out.println(prevFPS);
startTime = currentTime;
ticks = 0;
}
lastTime = currentTime;
}
}
}
/**
* repaints the SSCCE.
* This just shows the current FPS.
**/
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2D = (Graphics2D) g;
double roundedFPS = Math.round(prevFPS*10)/10.0;
g2D.setColor(new Color(0x000000));
g2D.drawString("FPS: " + roundedFPS, 20,20);
g.dispose();
}
/**
* runSSCCEELogic()
* This is where the run-time logic for the SSCCE example is.
* All it does is load and play a midi called "mymidi.mid" which is located in the same directory.
**/
public void runSSCCELogic()
{
if(logicLoops == 1)
{
midiPlayer.load("http://www.vgmusic.com/music/computer/microsoft/windows/touhou_6_stage3_boss.mid");
midiPlayer.play(true);
}
logicLoops++;
}
}
/**
* MidiPlayer
* A class that allows midi files to be loaded and played.
**/
class MidiPlayer
{
private Sequence seq;
private Sequencer seqr;
private Synthesizer synth;
private Receiver receiver;
private File midiFile;
private String midiID;
private boolean loaded;
private boolean usingHardwareSoundbank;
// CONSTRUCTORS
public MidiPlayer()
{
loaded = false;
try
{
seqr = MidiSystem.getSequencer();
synth = MidiSystem.getSynthesizer();
}
catch(Exception e)
{
System.out.println("MIDI error: It appears your system doesn't have a MIDI device or your device is not working.");
}
}
/**
* MidiPlayer(String fileName)
* Constructor that also loads an initial midi file.
* Preconditions: fileName is the name of the midi file to be loaded.
* Postconditions: The MidiPlayer is created and loaded with the midi specified by fileName.
**/
public MidiPlayer(String fileName)
{
this();
load(fileName);
}
// DATA METHODS
/**
* load(String fileName)
* loads a midi file into this MidiPlayer.
* Preconditions: fileName is the name of the midi file to be loaded.
* Postconditions: fileName is loaded and is ready to be played.
**/
public void load(String fileName)
{
this.unload();
try
{
URL midiURL = new URL(fileName);
// midiFile = new File(fileName);
seq = MidiSystem.getSequence(midiURL);
seqr.open();
synth.open();
System.out.println("MidiDeviceInfo: ");
for(MidiDevice.Info info : MidiSystem.getMidiDeviceInfo())
{
System.out.println("\t" + info);
}
System.out.println();
if(synth.getDefaultSoundbank() == null)
{
receiver = MidiSystem.getReceiver();
usingHardwareSoundbank = true;
System.out.println("using hardware soundbank");
}
else
{
receiver = synth.getReceiver();
usingHardwareSoundbank = false;
System.out.println("using default software soundbank:" + synth.getDefaultSoundbank());
}
seqr.getTransmitter().setReceiver(receiver);
seqr.setSequence(seq);
loaded = true;
}
catch(IOException ioe)
{
System.out.println("MIDI error: Problem occured while reading " + midiFile.getName() + ".");
}
catch(InvalidMidiDataException imde)
{
System.out.println("MIDI error: " + midiFile.getName() + " is not a valid MIDI file or is unreadable.");
}
catch(Exception e)
{
System.out.println("MIDI error: Unexplained error occured while loading midi.");
}
}
/**
* unload()
* Unloads the current midi from the MidiPlayer and releases its resources from memory.
**/
public void unload()
{
this.stop();
seqr.close();
midiFile = null;
loaded = false;
}
// OTHER METHODS
/**
* setMidiID(String id)
* associates a String ID with the current midi.
* Preconditions: id is the ID we are associating with the current midi.
**/
public void setMidiID(String id)
{
midiID = id;
}
/**
* getMidiID(String id)
*
**/
public String getMidiID()
{
return new String(midiID);
}
/**
* play(boolean reset)
* plays the currently loaded midi.
* Preconditions: reset tells our midi whether or nor to begin playing from the start of the midi file's current loop start point.
* Postconditions: If reset is true, then the loaded midi begins playing from its loop start point (default 0).
* If reset is false, then the loaded midi resumes playing from its current position.
**/
public void play(boolean reset)
{
if(reset)
seqr.setTickPosition(seqr.getLoopStartPoint());
seqr.start();
}
/**
* stop()
* Pauses the current midi if it was playing.
**/
public void stop()
{
if(seqr.isOpen())
seqr.stop();
}
/**
* isRunning()
* Returns true if the current midi is playing. Returns false otherwise.
**/
public boolean isRunning()
{
return seqr.isRunning();
}
/**
* loop(int times)
* Sets the current midi to loop from start to finish a specific number of times.
* Preconditions: times is the number of times we want our midi to loop.
* Postconditions: The current midi is set to loop times times.
* If times = -1, the current midi will be set to loop infinitely.
**/
public void loop(int times)
{
loop(times,0,-1);
}
/**
* loop(int times)
* Sets the current midi to loop from a specified start point to a specified end point a specific number of times.
* Preconditions: times is the number of times we want our midi to loop.
* start is our loop's start point in ticks.
* end is our loop's end point in ticks.
* Postconditions: The current midi is set to loop from tick start to tick end times times.
* If times = -1, the current midi will be set to loop infinitely.
**/
public void loop(int times, long start, long end)
{
if(start < 0)
start = 0;
if(end > seqr.getSequence().getTickLength() || end <= 0)
end = seqr.getSequence().getTickLength();
if(start >= end && end != -1)
start = end-1;
seqr.setLoopStartPoint(start);
seqr.setLoopEndPoint(end);
if(times == -1)
seqr.setLoopCount(Sequencer.LOOP_CONTINUOUSLY);
else
seqr.setLoopCount(times);
}
public void setVolume(double vol)
{
try
{
if(usingHardwareSoundbank)
{
ShortMessage volumeMessage = new ShortMessage();
for ( int i = 0; i < 16; i++ )
{
volumeMessage.setMessage( ShortMessage.CONTROL_CHANGE, i, 7, (int)(vol*127) );
receiver.send( volumeMessage, -1 );
}
}
else
{
MidiChannel[] channels = synth.getChannels();
for( int c = 0; channels != null && c < channels.length; c++ )
{
channels[c].controlChange( 7, (int)( vol*127) );
}
}
}
catch ( Exception e )
{
e.printStackTrace();
}
}
}
import javax.sound.midi.*;
import java.net.URL;
class PlayMidi {
public static void main(String[] args) throws Exception {
URL url = new URL("http://www.vgmusic.com/music/computer/microsoft/windows/touhou_6_stage3_boss.mid");
Sequence sequence = MidiSystem.getSequence(url);
Sequencer sequencer = MidiSystem.getSequencer();
sequencer.open();
sequencer.setSequence(sequence);
sequencer.start();
}
}
package gameEngine;
import javax.sound.midi.*;
import java.io.File;
import java.io.IOException;
import java.net.URL;
/**
* MidiPlayer
* author: Stephen Lindberg
* Last modified: Oct 14, 2011
*
* A class that allows midi files to be loaded and played.
**/
public class MidiPlayer
{
private Sequence seq;
private Sequencer seqr;
private Synthesizer synth;
private Receiver receiver;
private File midiFile;
private String midiID;
private boolean loaded;
private boolean usingHardwareSoundbank;
private float defaultTempo;
// CONSTRUCTORS
public MidiPlayer()
{
loaded = false;
try
{
seqr = MidiSystem.getSequencer();
synth = MidiSystem.getSynthesizer();
// print the user's midi device info
System.out.println("Setting up Midi Player...");
System.out.println("MidiDeviceInfo: ");
for(MidiDevice.Info info : MidiSystem.getMidiDeviceInfo())
{
System.out.println("\t" + info.getName() + ": " +info.getDescription());
}
System.out.println();
// obtain the receiver. This will be used for changing volume.
Soundbank soundbank = synth.getDefaultSoundbank();
if(soundbank == null)
{
receiver = MidiSystem.getReceiver();
usingHardwareSoundbank = true;
System.out.println("using hardware soundbank");
}
else
{
synth.loadAllInstruments(soundbank);
receiver = synth.getReceiver();
usingHardwareSoundbank = false;
System.out.println("using default software soundbank:" + soundbank);
}
seqr.getTransmitter().setReceiver(receiver);
}
catch(Exception e)
{
System.out.println("MIDI error: It appears your system doesn't have a MIDI device or your device is not working.");
}
}
/**
* MidiPlayer(String fileName)
* Constructor that also loads an initial midi file.
* Preconditions: fileName is the name of the midi file to be loaded.
* Postconditions: The MidiPlayer is created and loaded with the midi specified by fileName.
**/
public MidiPlayer(String fileName)
{
this();
load(fileName);
}
// DATA METHODS
/**
* load(String fileName)
* loads a midi file into this MidiPlayer.
* Preconditions: fileName is the name of the midi file to be loaded.
* Postconditions: fileName is loaded and is ready to be played.
**/
public void load(String fileName)
{
this.unload();
try
{
URL midiURL = getClass().getClassLoader().getResource(fileName);
seq = MidiSystem.getSequence(midiURL);
seqr.open();
synth.open();
// load our sequence into the sequencer.
seqr.setSequence(seq);
loaded = true;
defaultTempo = seqr.getTempoInBPM();
}
catch(IOException ioe)
{
System.out.println("MIDI error: Problem occured while reading " + midiFile.getName() + ".");
}
catch(InvalidMidiDataException imde)
{
System.out.println("MIDI error: " + midiFile.getName() + " is not a valid MIDI file or is unreadable.");
}
catch(Exception e)
{
System.out.println("MIDI error: Unexplained error occured while loading midi.");
}
}
/**
* unload()
* Unloads the current midi from the MidiPlayer and releases its resources from memory.
**/
public void unload()
{
this.stop();
seqr.close();
synth.close();
midiFile = null;
loaded = false;
}
// OTHER METHODS
/**
* setMidiID(String id)
* associates a String ID with the current midi.
* Preconditions: id is the ID we are associating with the current midi.
**/
public void setMidiID(String id)
{
midiID = id;
}
/**
* getMidiID(String id)
*
**/
public String getMidiID()
{
return new String(midiID);
}
/**
* play(boolean reset)
* plays the currently loaded midi.
* Preconditions: reset tells our midi whether or nor to begin playing from the start of the midi file's current loop start point.
* Postconditions: If reset is true, then the loaded midi begins playing from its loop start point (default 0).
* If reset is false, then the loaded midi resumes playing from its current position.
**/
public void play(boolean reset)
{
if(reset)
seqr.setTickPosition(seqr.getLoopStartPoint());
seqr.start();
}
/**
* stop()
* Pauses the current midi if it was playing.
**/
public void stop()
{
if(seqr.isOpen())
seqr.stop();
}
/**
* isRunning()
* Returns true if the current midi is playing. Returns false otherwise.
**/
public boolean isRunning()
{
return seqr.isRunning();
}
/**
* getTempo()
* Returns the current tempo of the MidiPlayer in BPM (Beats per Minute).
**/
public float getTempo()
{
return seqr.getTempoInBPM();
}
/**
* loop(int times)
* Sets the current midi to loop from start to finish a specific number of times.
* Preconditions: times is the number of times we want our midi to loop.
* Postconditions: The current midi is set to loop times times.
* If times = -1, the current midi will be set to loop infinitely.
**/
public void loop(int times)
{
loop(times,0,-1);
}
/**
* loop(int times)
* Sets the current midi to loop from a specified start point to a specified end point a specific number of times.
* Preconditions: times is the number of times we want our midi to loop.
* start is our loop's start point in ticks.
* end is our loop's end point in ticks.
* Postconditions: The current midi is set to loop from tick start to tick end times times.
* If times = -1, the current midi will be set to loop infinitely.
**/
public void loop(int times, long start, long end)
{
if(start < 0)
start = 0;
if(end > seqr.getSequence().getTickLength() || end <= 0)
end = seqr.getSequence().getTickLength();
if(start >= end && end != -1)
start = end-1;
seqr.setLoopStartPoint(start);
seqr.setLoopEndPoint(end);
if(times == -1)
seqr.setLoopCount(Sequencer.LOOP_CONTINUOUSLY);
else
seqr.setLoopCount(times);
}
/**
* resetTempo()
* Resets the MidiPlayer's tempo the the initial tempo of its current midi.
**/
public void resetTempo()
{
this.changeTempo(this.defaultTempo);
}
/**
* changeTempo(float bpm)
* Changes the MidiPlayer's current tempo.
* Preconditions: bpm is the MidiPlayer's new tempo in BPM (Beats per Minute).
* Postconditions: The MidiPlayer's current tempo is set to bpm BPM.
**/
public void changeTempo(float bpm)
{
double lengthCoeff = bpm/seqr.getTempoInBPM();
seqr.setLoopStartPoint((long) (seqr.getLoopStartPoint()*lengthCoeff));
seqr.setLoopEndPoint((long) (seqr.getLoopEndPoint()*lengthCoeff));
seqr.setTempoInBPM(bpm);
}
public void setVolume(double vol)
{
System.out.println("Midi volume change request: " + vol);
try
{
if(usingHardwareSoundbank)
{
ShortMessage volumeMessage = new ShortMessage();
for ( int i = 0; i < 16; i++ )
{
volumeMessage.setMessage( ShortMessage.CONTROL_CHANGE, i, 7, (int)(vol*127) );
receiver.send( volumeMessage, -1 );
}
}
else
{
MidiChannel[] channels = synth.getChannels();
for( int c = 0; c < channels.length; c++ )
{
if(channels[c] != null) {
channels[c].controlChange( 7, (int)( vol*127) );
}
}
}
}
catch ( Exception e )
{
e.printStackTrace();
}
}
}