/**
     * 方法: 以流的形式输出音频至浏览器.
     * @param String $filePath 以音频流格式输出mp3、wav等文件输出到浏览器.
     * @return void.
     */
    function print_mp3($filePath){
        $strContext = stream_context_create(array('http'=>array('method'=>'GET','header'=>"Accept-language: zh-cn\r\n")));
        $fpOrigin = fopen($filePath, 'rb', false, $strContext);
        header('Content-disposition: inline; filename="index.mp3"');
        header('Pragma: no-cache');
        header('Content-type: audio/mpeg');
        header('Content-Length: '.filesize($filePath));
        while(!feof($fpOrigin)){
            $buffer=fread($fpOrigin, 4096);
            echo $buffer;
            flush();
        }
        fclose($fpOrigin);
    }