code: public static byte[] decode(char[] src) {
          byte[] dst = new byte[src.length / 2];
  
          for (int si = 0, di = 0; di < dst.length; di++) {
              byte high = decode[src[si++] & 0x7f];
              byte low  = decode[src[si++] & 0x7f];
              dst[di] = (byte) ((high << 4) + low);
          }
  
          return dst;
      }
docs: Decode base16 chars to bytes.
  
  @param src   Chars to decode.
  
  @return Decoded bytes.