function b64ToUint6 (nChr) {

  return nChr > 64 && nChr < 91 ?
      nChr - 65
    : nChr > 96 && nChr < 123 ?
      nChr - 71
    : nChr > 47 && nChr < 58 ?
      nChr + 4
    : nChr === 43 ?
      62
    : nChr === 47 ?
      63
    :
      0;

}
function b64ToUint6 (nChr) {

  return nChr > 64 && nChr < 91 ?
      nChr - 65
    : nChr > 96 && nChr < 123 ?
      nChr - 71
    : nChr > 47 && nChr < 58 ?
      nChr + 4
    : nChr === 43 ?
      62
    : nChr === 47 ?
      63
    :
      0;

}
function b64ToUint6 ( nChr ) { return nChr > 64 && nChr < 91 ? nChr - 65 : nChr > 96 && nChr < 123 ? nChr - 71 : nChr > 47 && nChr < 58 ? nChr + 4 : nChr === 43 ? 62 : nChr === 47 ? 63 : 0 ; }
/*\
|*|
|*|  Base64 / binary data / UTF-8 strings utilities
|*|
|*|  https://developer.mozilla.org/en-US/docs/Web/JavaScript/Base64_encoding_and_decoding
|*|
\ /* Array of bytes to base64 string decoding
/ * \ | * | | * | Base64 / binary data / UTF - 8 strings utilities | * | | * | https : // developer . mozilla . org / en - US / docs / Web / JavaScript / Base64_encoding_and_decoding | * | \ / * Array of bytes to base64 string decoding
Convert a 64 - bit number to an unsigned 6 - bit integer