JLayer总是引发ArrayIndexOutOfBounds异常

Question

我使用JLayer对MP3进行解码，并将其存储为PCM数据。但是，无论我使用什么MP3文件，我都会得到一个索引为443的ArrayIndexOutOfBoudnsException。我听说这种情况只发生在特定的MP3s上，但是它发生在我在这里播放的每个MP3的每个帧上，这是我的代码：

private short[] getPCM(Header frameHeader, Bitstream bs) {
    short[] pcm = null;
    try {
        Decoder d = new Decoder();
        SampleBuffer buffer = (SampleBuffer) d.decodeFrame(frameHeader, bs);
        pcm = buffer.getBuffer();
    } catch (ArrayIndexOutOfBoundsException | DecoderException e) {
        System.err.println("JLayer, stap it");
    }
    return pcm;
}

并使用以下代码调用该方法：

while ((frameHeader = bs.readFrame()) != null) {
    short[] pcm = getPCM(frameHeader, bs);

    for(short i : pcm){
        try {
            os.write(i);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }       
}

堆栈跟踪：

java.lang.ArrayIndexOutOfBoundsException: 433
at javazoom.jl.decoder.Bitstream.get_bits(Unknown Source)
at javazoom.jl.decoder.LayerIIIDecoder.decode(Unknown Source)
at javazoom.jl.decoder.LayerIIIDecoder.decodeFrame(Unknown Source)
at javazoom.jl.decoder.Decoder.decodeFrame(Unknown Source)
at com.dentonposs.Canvas.getPCM(Canvas.java:70)
at com.dentonposs.Canvas.paintComponent(Canvas.java:48)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JLayeredPane.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paintToOffscreen(Unknown Source)
at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(Unknown Source)
at javax.swing.RepaintManager$PaintManager.paint(Unknown Source)
at javax.swing.RepaintManager.paint(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at java.awt.GraphicsCallback$PaintCallback.run(Unknown Source)
at sun.awt.SunGraphicsCallback.runOneComponent(Unknown Source)
at sun.awt.SunGraphicsCallback.runComponents(Unknown Source)
at java.awt.Container.paint(Unknown Source)
at java.awt.Window.paint(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.prePaintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.access$700(Unknown Source)
at javax.swing.RepaintManager$ProcessingRunnable.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

Answer 1

您需要在每次调用Bitstream.closeFrame() - so之间调用readFrame()

while ((frameHeader = bs.readFrame()) != null) {
    short[] pcm = getPCM(frameHeader, bs);

    bs.closeFrame();

    .. more ..

Answer 2

从它的外观来看，您正在尝试让解码器一遍又一遍地解码相同的帧。这将不起作用，BitStream具有内部状态(指向要读取的下一个位的指针)，在解码该帧后将变得无效。异常表示它试图读取缓冲区容量。

必须对每个帧只调用一次decodeFrame()。

编辑:您的堆栈跟踪没有显示实际读取数据的位置。因为异常在component方法中，所以我假设您在另一个线程或其他地方读取了框架。

另外，查看您的getPCM()方法:该代码将永远无法工作。您不能为每个帧创建一个新的解码器实例--这将根本无法工作，因为解码器具有大量的内部状态，这是必要的，并且取决于前一个帧。您必须创建解码器一次，并重复使用它的所有帧.

看看javazoom.jl.player.Player的来源--它在play(int)方法中显示了一个适当的play循环(它只有几行长，但您必须遵守那里显示的调用顺序，否则会破坏解码器和解码器持有的对象的正确状态)。