var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var base64DecodeChars = new Array(
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
    -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
    -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1);

function base64decode(str) {
    var c1, c2, c3, c4;
    var i, len, out;
    len = str.length;
    i = 0;
    out = "";
    while(i < len) {
        do {
            c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
        } while(i < len && c1 == -1);
        if (c1 == -1) break;
        do {
            c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
        } while(i < len && c2 == -1);
        if (c2 == -1) break;
        out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));
        do {
            c3 = str.charCodeAt(i++) & 0xff;
            if (c3 == 61)  return out;
            c3 = base64DecodeChars[c3];
        } while(i < len && c3 == -1);
        if(c3 == -1) break;
        out += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));
        do {
            c4 = str.charCodeAt(i++) & 0xff;
            if(c4 == 61) return out;
            c4 = base64DecodeChars[c4];
        } while(i < len && c4 == -1);
        if(c4 == -1) break;
        out += String.fromCharCode(((c3 & 0x03) << 6) | c4);
    }
    return out;
}

function jiemi(str) {
	if (str.search(/^imusic/i)!=-1) {
		str=str.replace("imusic://","");
        str=base64decode(str).replace(/^AA|ZZ$/gi,"");
        return str
    }   
}