android – 通过Eclipse上的缓冲区播放AudioTrack缓冲区音乐 – 没有声音

2023年10月3日 209次阅读

我正在为
Android 2.1编程.你可以帮助我解决以下问题吗？

我有三个文件,通用的目的是通过缓冲区播放带有audiotrack缓冲区的声音.我在这里非常绝望,因为我尝试了所有的东西,而且我的扬声器仍然没有声音(而android的集成媒体播放器通过模拟器播放声音没有问题).

源代码：

一个audioplayer类,实现音轨.它将收到一个缓冲区,其中包含声音.

    public AudioPlayer(int sampleRate, int channelConfiguration, int audioFormat) throws ProjectException {
        minBufferSize = AudioTrack.getMinBufferSize(sampleRate, channelConfiguration, audioFormat);
        audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, sampleRate, channelConfiguration,
                                    audioFormat, minBufferSize, AudioTrack.MODE_STREAM); 

        if(audioTrack == null)
            throw new ProjectException("Erreur lors de l'instantiation de AudioTrack");

        audioTrack.setStereoVolume((float)1.0, (float)1.0);
    }

    @Override
    public void addToQueue(short[] buffer) {
         audioTrack.write(buffer, 0, buffer.length*Short.SIZE);
         if(!isPlaying ) {
             audioTrack.play();
             isPlaying = true;
         }
    }

一个模型类,我用它来填充缓冲区.通常情况下,它会从文件加载声音,但这里只使用模拟器(440Hz)进行调试.

缓冲区大小选择非常松散;通常第一个缓冲区大小应该是6615然后是4410.这也是仅用于调试.

public void onTimeChange() {
    if(begin) {

                    //First fill about 300ms

        begin = false;
        short[][] buffer = new short[channels][numFramesBegin];
                    //numFramesBegin is for example 10000
                    //For debugging only buffer[0] is useful
        fillSimulatedBuffer(buffer, framesRead);
        framesRead += numFramesBegin;
        audioPlayer.addToQueue(buffer[0]);

    }

    else {
        try {
            short[][] buffer = new short[channels][numFrames];

                            //Afterwards fill like 200ms

            fillSimulatedBuffer(buffer, framesRead);
            framesRead += numFrames;
            audioPlayer.addToQueue(buffer[0]);
        } catch (Exception e) {
            e.printStackTrace();
        }


    }
}

private short simulator(int time, short amplitude) {
            //a pure A (frequency=440)
            //this is probably wrong due to sampling rate, but 44 and 4400 won't work either
    return (short)(amplitude*((short)(Math.sin((double)(simulatorFrequency*time)))));
}

private void fillSimulatedBuffer(short[][] buffer, int offset) {
         for(int i = 0; i < buffer[0].length; i++)
        buffer[0][i] = simulator(offset + i, amplitude);
}

每200毫秒调用model.ontimechange()的timeTask类.

public class ReadMusic extends TimerTask {
private final Model model;

public ReadMusic(Model model) {
    this.model = model;
}


@Override
public void run() {
    System.out.println("Task run");
    model.onTimeChange();
}

}

调试显示了什么：

> timeTask工作正常,它完成了它的工作;
>缓冲区值似乎是连贯的,缓冲区大小大于minBufSize;
> Audiotrack的演奏状态是“正在播放”
>模型函数中没有异常.

任何想法将不胜感激！

最佳答案 好的我发现了问题.

关于AudioTrack和短缓冲区输入的当前AudioTrack文档中存在错误：指定的缓冲区大小应该是缓冲区本身的大小(buffer.length)而不是以字节为单位的大小.

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