title: MP4 File Format Specification
body: <p>I am writing some code to parse MP4 files ...</p>
  
  <p>Is there a free source to get documentation on the MP4 File Format Specification. So far I have only found an ISO document which I would need to purchase <a href="http://www.iso.org/iso/catalogue_detail.htm?csnumber=38538" rel="noreferrer">ISO PDF</a>. Is MP4 Not an open standard ?</p>