Fragmented MP4 File Format

As I have already mentioned in one of  my previous posts about MP4 file format with MOOV box and media data box. Each terminology is represented by “box” in MP4 file format. As microsoft used fragmented MP4 in their smooth streaming technique where fragments are internally organized in a simple contiguous MP4 file.  Each fragment section consists of two parts: Movie Fragment (moof) and media data (mdat). Moof section carry more accurate fragment level metadata and media is contained in the mdat section.

We have used MP4split to generate the fmp4 file.  There is another opensource tool MP4 explorer from cmstream that is used to analyze the header information of a MP4 file. Below you can see a snapshot that shows the fragments information of my encoded mp4 file. Chunks information are delivered to the client through client manifest file (*.ismc).

If you are really interested to see what is in the client manifest file you can look into the following link :

http://mithunme.wordpress.com/2009/11/04/information-in-the-ismc-and-ism-file/