媒体播放器 - 声音停止播放

Question

>我正在创建一个类女巫加载一些声音。但是，isPlay在一段时间后继续抛出异常，然后永久停止播放该特定声音，而其他声音则继续播放正常。

public class MySound {
int m_IdMyId;
int m_ResId;
boolean m_IsLoaded;
MediaPlayer m_Media;
public MySound(int idMyId, int resId){
m_IdMyId = idMyId;
m_ResId = resId;
m_IsLoaded = false;
m_Media = null;
}
}

在这个m_IdMyId中，这只是我的游戏的ID。m_ResId有点像R.raw.mysound1. 我认为m_IsLoaded在我同步加载时会自动设置为true。m_Media是MediaPlayer对象。

我经常打电话给stop()，因为这是一个游戏，我需要每隔一秒左右检查一次，以确保某些声音停止。正是在这里，它在调用snd.m_Media.isPlaying()时引发异常。

我似乎无法访问e以查看错误是什么。

我也想知道如何正确设置m_IsLoaded。我如何知道声音何时已完全加载并可供使用？

这是我的管理课：

public class MySoundManager {
MainActivity m_Context;
ArrayList<MySound> mySounds;
public MySoundManager(MainActivity context) {
m_Context = context;
mySounds = new ArrayList<MySound>();
mySounds.add(new MySound(8, R.raw.mysound1));
mySounds.add(new MySound(10, R.raw.mysound2));
mySounds.add(new MySound(22, R.raw.mysound3));
mySounds.add(new MySound(100, R.raw.click));
mySounds.add(new MySound(101, R.raw.error));
for(MySound mysound : mySounds) {
mysound.m_Media = MediaPlayer.create(m_Context, mysound.m_ResId); // no need to call prepare(); create() does that for you
mysound.m_IsLoaded = true;
}
}
// I call this when the main thread calls onResume
public void onResume(){
for(MySound mysound : mySounds) {
if(mysound.m_Media == null) {
mysound.m_Media = MediaPlayer.create(m_Context, mysound.m_ResId); // no need to call prepare(); create() does that for you
mysound.m_IsLoaded = true;
}
}
}
// I call this when the main thread calls onPause
public void onPause(){
for(MySound mysound : mySounds) {
if(mysound.m_Media != null) {
mysound.m_Media.stop();
mysound.m_Media.release();
mysound.m_Media = null;
}
}
}
public boolean IsAllLoaded(){
for(MySound mysound : mySounds) {
if(!mysound.m_IsLoaded) return false;
}
return true;
}
public MySound FindMySoundByIdMyId(int idMyId){
try {
for(MySound mysound : mySounds) {
if (mysound.m_IdMyId == idMyId) return mysound;
}
}catch(Exception e) {
MySound snd;
snd = null; // ToDo
}
return null;
}
public void play(int idMyId){
MySound snd;
try{
if((snd = FindMySoundByIdMyId(idMyId)) != null)
snd.m_Media.start();
}catch(IllegalStateException e) {
snd = null; // ToDo
}
}
public void pause(int idMyId){
MySound snd;
try{
if((snd = FindMySoundByIdMyId(idMyId)) != null &&
snd.m_Media.isPlaying())
snd.m_Media.pause();
}catch(IllegalStateException e) {
snd = null; // ToDo
}
}
public void pauseAll(){
try{
for (MySound mysound : mySounds) {
if(mysound.m_Media.isPlaying())
mysound.m_Media.pause();
}
}catch(IllegalStateException e) {
MySound snd;
snd = null; // ToDo
}
}
public boolean isPlaying(int idMyId, MySound[] fill){
MySound snd;
fill[0] = null;
try{
if((snd = FindMySoundByIdMyId(idMyId)) != null){
fill[0] = snd;
return snd.m_Media.isPlaying();
}
}catch(IllegalStateException e) {
snd = null; // ToDo
}
return false;
}
public void stop(int idMyId){
MySound snd;
try{
if((snd = FindMySoundByIdMyId(idMyId)) != null &&
snd.m_Media.isPlaying())
snd.m_Media.stop();
}catch(IllegalStateException e) {
snd = null; // ToDo
}
}
// The str is in the format
// number id, 1 = on 0 = off,dont play if this id playing;
public void PlaySound(String str) {
boolean isplaying;
int i, len, id, idDontPlay, milliNow;
String[] strARR = str.split(";");
String[] strARR2;
Integer[] tmpIntARR;
ArrayList<Integer[]> onARR = new ArrayList<Integer[]>();
ArrayList<Integer> offARR = new ArrayList<Integer>();
MySound snd;
for (i = 0, len = strARR.length; i < len; i++) {
if(strARR[i].length() <= 0) continue;
if((strARR2 = strARR[i].split(",")) != null &&
strARR2.length >= 3 &&
strARR2[0].length() > 0 &&
strARR2[1].length() > 0 &&
strARR2[2].length() > 0){
id = Integer.parseInt(strARR2[0]);
idDontPlay = Integer.parseInt(strARR2[2]);
tmpIntARR = new Integer[2];
tmpIntARR[0] = id;
tmpIntARR[1] = idDontPlay;
if(Integer.parseInt(strARR2[1]) == 1){
onARR.add(tmpIntARR);
} else offARR.add(id);
}
}
// Turn off all sounds that need to be turned off
for (i=0,len=offARR.size();i<len;i++) {
id = offARR.get(i);
stop(id);
}
// Turn all sounds that need to be turned on,
// but only if the sound that blocks a new sound is not playing
for (i=0,len=onARR.size();i<len;i++) {
tmpIntARR = onARR.get(i);
id = tmpIntARR[0];
idDontPlay = tmpIntARR[1];
// We dont play if the idDontPlay sound is already playing
if((snd = FindMySoundByIdMyId(idDontPlay)) != null &&
snd.m_Media.isPlaying())
continue;
if((snd = FindMySoundByIdMyId(id)) != null){
isplaying = snd.m_Media.isPlaying();
milliNow = snd.m_Media.getCurrentPosition();
if(milliNow > (snd.m_Media.getDuration() - 1000) ||
(!isplaying && milliNow > 0)){
snd.m_Media.seekTo(0); // Half a second inside
}
if(!isplaying) snd.m_Media.start();
}
}
}
}

Answer 1

为每个声音创建 MediaPlayer 实例不是获得低延迟的好做法，尤其是对于短剪辑。MediaPlayer 适用于较长的剪辑，例如音乐文件，它使用大缓冲区，因此，较大的缓冲区意味着高延迟。此外，安卓设备上还有音频焦点机制，可能会干扰您的声音播放会话。因此，我强烈建议您使用SoundPool来播放游戏声音等短片。