BBC News - Text Decode animation expression

after effect loop.js

//READS INPUTED TEXT
var string = text.sourceText;
var lng_size = string.length;
var lng_char = string.split("");

//DROPS SPACES
var srt_string = string.replace(/ /gi,"");
var srt_size = srt_string.length;
var srt_char = srt_string.split("");

//ANIMATION SETUP
var word_loop = 1; //Times animation is looped
var pause = 7; //Frames the animation is paused for
var loop_length = srt_size*word_loop;
var ani_length = loop_length+pause;
var reverse = false;
var layerTime = timeToFrames(time-inPoint);

var output = "";

var loopFrame = layerTime%ani_length;
if (loopFrame >= loop_length) {
 var offset = 0;
} else if (reverse == true) {
 var offset = (1+loopFrame)%srt_size;
} else {
 var offset = srt_size-(1+loopFrame)%srt_size;
}

for (i = 0; i < lng_size; i++) {
 if (lng_char[i] == " ") {
  output += " ";
 } else {
  output += srt_char[Math.abs(offset%srt_size)];
  offset++;
 }
}

output