title: What's the reasoning behind the limit on BitmapData width/height in Flash 9 and lower being 2880?
body: <p>As mentioned in a comment to <a href="https://stackoverflow.com/questions/6812462/load-image-of-size-greater-than-2880-in-bitmap">this question</a>, the choice of exactly 2880 pixels being the maximum width and height of a <a href="http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/display/BitmapData.html" rel="nofollow noreferrer">flash.display.BitmapData</a> object in Flash 9 and lower seems a bit arbitrary. I could understand, or at least guess at a reason for, quite a few choices roughly in the same ballpark, like ...</p>
  
  <ul>
  <li>2048 - 2^11</li>
  <li>2160 - double of 1080p vertical resolution</li>
  <li>2480 or 3508 - short and long side of an A4 paper sized page at 300 dpi, respectively</li>
  <li>2550 or 3300 - short and long side of a letter format sized page at 300 dpi</li>
  <li>2896 - side length of a square bitmap with (almost) 2^23 pixels</li>
  </ul>
  
  <p>... but try as I might, I can't find any reason for <em>exactly</em> 2880 pixels. So the question is, what's the reasoning behind this strange (to me) limit?</p>