从APK扩展文件加载音频的Soundpool [英] Loading SoundPool with audio from APK Expansion file

问题描述

在文档它说：

  

如果您使用的扩展文件存储多媒体文件，ZIP文件
  还可以让你使用Android的媒体播放调用，提供
  偏移量和长度的控制（如MediaPlayer.setDataSource（）和
  SoundPool.load（））。

我有10个小型的.ogg文件，我想用Sou​​ndPool.load（FD FileDescriptor的，长的偏移量，长度长，INT优先）来加载这些音频文件。我已经写了一些code，但是当我运行它，我得到错误信息：

  

无法加载示例：（空）

，显然音频不会播放。以下是我尝试：

 公共类MainActivity延伸活动{    的Soundpool声音;
    布尔加载= FALSE;
    INT流ID;
    INT theId;    @覆盖
    保护无效的onCreate（捆绑savedInstanceState）{
        super.onCreate（savedInstanceState）;
        System.gc（）的;
        的setContentView（R.layout.activity_main）;
        听起来=新的Soundpool（10，AudioManager.STREAM_MUSIC，0）;
        sounds.setOnLoadCompleteListener（新SoundPool.OnLoadCompleteListener（）{
            @覆盖
            公共无效的onLoadComplete（SP的Soundpool，诠释SID，诠释状态）{
                加载=真实的;
        }}）;
        loadSounds（）;
        playSound（theID）;
    }    私人无效loadSounds（）{
        AssetFileDescriptor描述符= NULL;
        尝试{
            描述= getFileDescriptor（这一点，audio_files / end_cr​​edits.ogg）;
        }赶上（例外五）{
        } {最后
            如果（描述符！= NULL）
                尝试{descriptor.close（）;}赶上（IOException异常五）{}
        }
    theId = sounds.load（descriptor.getFileDescriptor（），descriptor.getStartOffset（），descriptor.getLength（），1）;
}
    公共静态AssetFileDescriptor getFileDescriptor（上下文CTX，字符串路径）{
        AssetFileDescriptor描述符= NULL;
        尝试{
            子presourceFile邮编= APKExpansionSupport.getAPKExpansionZipFile（CTX，4，-1）;
            描述= zip.getAssetFileDescriptor（路径）;
        }赶上（IOException异常五）{
            e.printStackTrace（）;
        }
        返回描述;
    }
    私人无效playSound（INT soundID）{
        如果（装入）{
            流ID = sounds.play（soundID，1，1，1，0，1）;}
    }
}
 

解决方案

好吧，好像原因是音频没有加载速度不够快。我把playSound（theID）;右后loadSounds（）;而它需要几秒钟加载它才能进行播放。但是，code为工作到这一点。

In the documentation it says:

If you're using your expansion files to store media files, a ZIP file still allows you to use Android media playback calls that provide offset and length controls (such as MediaPlayer.setDataSource() and SoundPool.load()).

I have 10 small .ogg files and I want to use SoundPool.load (FileDescriptor fd, long offset, long length, int priority) to load these audio files. I've written some code, but when I run it I get error message:

"Unable to load sample: (null)"

, and obviously the audio isn't played. Here is what I attempted:

public class MainActivity extends Activity {

    SoundPool sounds;
    boolean loaded = false;
    int streamID;
    int  theId;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        System.gc();
        setContentView(R.layout.activity_main);
        sounds = new SoundPool(10, AudioManager.STREAM_MUSIC,0);
        sounds.setOnLoadCompleteListener(new SoundPool.OnLoadCompleteListener() {
            @Override
            public void onLoadComplete(SoundPool sp, int sid, int status) {
                loaded = true;
        }});
        loadSounds();
        playSound(theID);
    }

    private void loadSounds() {
        AssetFileDescriptor descriptor = null;
        try {
            descriptor = getFileDescriptor(this, "audio_files/end_credits.ogg");
        } catch (Exception e) {
        } finally {
            if (descriptor != null)
                try{descriptor.close();} catch (IOException e) {}
        }
    theId =   sounds.load(descriptor.getFileDescriptor(), descriptor.getStartOffset(), descriptor.getLength(), 1);
}
    public static AssetFileDescriptor getFileDescriptor(Context ctx, String path) {
        AssetFileDescriptor descriptor = null;
        try {
            ZipResourceFile zip = APKExpansionSupport.getAPKExpansionZipFile(ctx, 4, -1);
            descriptor = zip.getAssetFileDescriptor(path);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return descriptor;
    }
    private void playSound(int soundID){
        if(loaded){
            streamID = sounds.play(soundID, 1, 1, 1, 0, 1);}
    }
}

解决方案

Ok, seems like the reason is audio isn't loading fast enough. I put playSound(theID); right after loadSounds(); whereas it needs couple seconds to load before it can be played. But the code is working up to that point.

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