Crock32: The Base32 implementation outlined by Douglas Crockford

crock32.class.php

<?php
/**
 * Spec here: http://www.crockford.com/wrmg/base32.html
 * I took the liberty of collapsing the decode of 'u' into 'v's slot, since that matches the visual funnelling of L, I, and O.
 * 
 * @package default
 * @author Bryan Elliott
 **/
abstract class Crock32 {
	static private $encodeMap = array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','J','K','M','N','P','Q','R','S','T','V','W','X','Y','Z');
	static private $decodeMap = array('L'=>1,'I'=>1,'O'=>0,'U'=>27);
	static private function decodeMap($ch) {
		if (empty(self::$decodeMap['a'])) 
			forEach(self::$encodeMap as $i=>$v) self::$decodeMap[$v]=$i;
		return self::$decodeMap[strToUpper($ch)];
	}
	static private function bitsFromString($str) {
		$bStr = array();
		for ($i=0; $i<strlen($str); $i++)
			$bStr[]= str_pad(base_convert(ord($str[$i]), 10, 2), 8, '0', STR_PAD_LEFT);
		return join('', $bStr);		
	}
	static private function b32FromBits($bits) {
		$bStr = str_split($bits, 5);
		$enc='';
		for($i=0; $i<count($bStr); $i++) 
			$enc.=self::$encodeMap[base_convert(str_pad($bStr[$i],5,'0'),2,10)];
		return $enc;		
	}
	static private function bitsFromb32($str) {
		$bStr=array();
		$str = preg_replace('/[^\d\w]/','',$str);
		for ($i=0; $i<strlen($str); $i++) 
			$bStr[]=str_pad(base_convert(self::decodeMap($str[$i]),10,2),5,'0',STR_PAD_LEFT);
		return join('', $bStr);
	}
	static private function stringFromBits($bits) {
		$bStr = str_split(substr($bits,0,floor(strlen($bits)/8)*8), 8);
		$ret = '';
		for ($i=0; $i<count($bStr); $i++) {
			$b = $bStr[$i];
			$o = base_convert($b, 2, 10);
			$c = chr($o);
			$ret.=$c;
		}
		return $ret;
	}
	static function encode($str) {
		return self::b32FromBits(self::bitsFromString($str));
	}
	static function decode($enc) {
		return self::stringFromBits(self::bitsFromb32($enc));
	}
}

crock32.js

/**
 * Spec here: http://www.crockford.com/wrmg/base32.html
 * I took the liberty of collapsing the decode of 'u' into 'v's slot, since that matches the visual funnelling of L, I, and O.
 * 
 * @package default
 * @author Bryan Elliott
 **/
var Crock32 = (function (parseInt, length) {
	var i, 
		encodeMap = '0123456789ABCDEFGHJKMNPQRSTVWXYZ'.split(''),
		decodeMap = { L:1,I:1,O:0,U:27 },
		splitBy8 = /.{1,8}/g,
		splitBy5 = /.{1,5}/g;
	for (i in encodeMap) decodeMap[encodeMap[i]]=parseInt(i);
	function pad(str, len, right) {
		while (str[length] < len) str = (right?'':'0')+str+(right?'0':'');
		return str;
	}
	return {
		encode: function (str) {
			var i, bStr = '', ret='';
			for (i=0; i<str[length]; i++)
				bStr+=pad(str.charCodeAt(i).toString(2), 8);
			bStr = bStr.match(splitBy5);
			for(i=0; i<bStr[length]; i++) 
				ret+=encodeMap[parseInt(pad(bStr[i], 5, 1),2)];
			return ret;
		},
		decode: function (str) {
			var i, bStr = '', bits, ret = '';
			str = str.replace(/\W|_/g, '', str);
			for (i=0; i<str[length]; i++) 
				bStr+=pad(decodeMap[str.charAt(i).toUpperCase()].toString(2),5);
			bStr = bStr.substr(0,~~(bStr[length]/8)*8).match(splitBy8);
			for (i=0; i<bStr[length]; i++)
				ret+=String.fromCharCode(parseInt(bStr[i], 2));
			return ret;			
		}
	};
})(parseInt, 'length');

PHP's str_split for Javascript

Javascript str_split: 
String.prototype.strSplit = function (n) {
	return this.match(new RegExp('.{1,'+(n||1)+'}', 'g'));
}

Bryan, could you be so kind and improve JS version to encode Uint8array?