Raw binary Communication between actionscript and javascript

decode.as

protected function decode(str:String):ByteArray
{
	var alphabet:String = 'abcdefghijklmnopqrstuvwxyz'; // only first 16 chars used
	var lookup:Object = new Object;
	var len:Number = str.length;
	var enc:Array = [0,0];
	var result:ByteArray = new ByteArray;
	if(str.length % 2)
		throw new Error("Decode failed: The string is not correctly encoded.");
	var position:Number = -1;
	while(++position < 26)
	lookup[alphabet.charAt(position)] = position;
	position = 0;
	while(position < len){
	enc[0] = lookup[str.charAt(position)];
	enc[1] = lookup[str.charAt(position+1)];
	position+=2;
	result.writeByte(-128 + 16*enc[0] + enc[1]);
	}
	return result;
}

encode.js

//encode the buffer from position of length len
function encode (buffer, position, len){
	var len = Math.min(len, buffer.byteLength-(position));
	position = position-1;
	var dataView = new DataView(buffer);
	var result = "";
	var n = 0;
	len = len + position + 1;
	while(++position <  len){
		n = 128 + dataView.getUint8(position);
		result += B64.alphabet.charAt(n / 16) + B64.alphabet.charAt(n % 16) ;
	}
	//console.log(result.length);
	return result;
}