public static byte[] encode(byte[] input, int inOffset, int inLen)
    {
        final byte[] output = new byte[((inLen + 2) / 3) * 4];
        encode(input, inOffset, inLen, output, 0);
        return output;
    }
public static byte [ ] encode ( byte [ ] input , int inOffset , int inLen ) { final byte [ ] output = new byte [ ( ( inLen + 2 ) / 3 ) * 4 ] ; encode ( input , inOffset , inLen , output , 0 ) ; return output ; }
Fast Base 64 encode as described in RFC 1421.