java - Java声音API。从调音台获取支持的音频格式

Question

我试图从通过USB连接到我的PC的外部调音台获得一条线路。
因此，我编写了一个简单的程序来列出所有混音器及其各自的源代码行(输出)和目标代码行(输入)，并且可以正常运行:

import javax.sound.sampled.*;

public class TestResources {
    public static void main(String args[]) {
        try {
            Mixer.Info [] mixers = AudioSystem.getMixerInfo();
            for(int i = 0 ; i< mixers.length; i ++) {
                System.out.println((i+1)+". " + mixers[i].getName() + " --> " + mixers[i].getDescription() );

                Line.Info [] sourceLines = AudioSystem.getMixer(mixers[i]).getSourceLineInfo();
                System.out.println("\tSource Lines:" );
                for(int j = 0; j< sourceLines.length; j++) {
                    System.out.println("\t" + (j+1) + ". " + sourceLines[j].toString() );
                }
                System.out.println();

                Line.Info [] targetLines = AudioSystem.getMixer(mixers[i]).getTargetLineInfo();                 
                System.out.println("\tTarget Lines:" );
                for(int j = 0; j< targetLines.length; j++) {
                    System.out.println("\t" + (j+1) + ". " + targetLines[j].toString() );

                }       
                System.out.println("\n" );
            }           
        }
        catch(Exception e) {
            e.printStackTrace();
        }
    }
}

但是，当我实际尝试获取该行时，我需要这样:

    AudioFormat format = new AudioFormat(44100, 16, 2, true, true);
    Mixer.Info [] mixers = AudioSystem.getMixerInfo();
    final TargetDataLine microphone = AudioSystem.getTargetDataLine(format, mixers[2]);

我收到一条错误消息，指出该行不支持该格式:

java.lang.IllegalArgumentException: Line unsupported: interface TargetDataLine supporting format PCM_SIGNED 44100.0 Hz, 16 bit, stereo, 8 bytes/frame, big-endian

如何扩展初始程序以打印每行支持的格式？
提前致谢。

Answer 1

此方法打印Line.Info对象支持的格式:

static void showLineInfoFormats(final Line.Info lineInfo)
{
  if (lineInfo instanceof DataLine.Info)
   {
     final DataLine.Info dataLineInfo = (DataLine.Info)lineInfo;

     Arrays.stream(dataLineInfo.getFormats())
           .forEach(format -> System.out.println("    " + format.toString()));
   }
}