Java linux lame 终端执行和代码执行命令生成的文件不一样?

public class Test{

    public static void main(String[] args) {
try{

        String shellString = "lame -b 16 /java/5/a.wav";
        String[] cmd = new String[]{"sh","-c",shellString};
        Process process = Runtime.getRuntime().exec(cmd);
        //Process process=Runtime.getRuntime().exec("lame -b 16 /java/5/a.wav"); // lame 你的.wav文件,简易版

          process.waitFor(); //阻塞，直到上述命令执行完,一定要在文件close()关闭前面
          process.getOutputStream().close();
          process.getInputStream().close();
          process.getErrorStream().close();

       }catch (Throwable e){
     
     }

    }

}