# How does MP4 encoding work?

**URL:** <https://www.ruby-forum.com/t/how-does-mp4-encoding-work/157109>\
**Category:** Ruby\
**Created:** [January 7, 2009, 12:34pm UTC](https://www.ruby-forum.com/t/how-does-mp4-encoding-work/157109 "2009-01-07T12:34:59Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Larz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/85f322/32.png) [@Larz](https://www.ruby-forum.com/u/Larz)\
**Post date:** [January 7, 2009, 12:34pm UTC](https://www.ruby-forum.com/t/how-does-mp4-encoding-work/157109/1 "2009-01-07T12:34:59Z")

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I am curious on how MP4 files are encoded and why is it that I can  
only play my MP4 files in ITunes ? Obviously there is some protection  
involved, but it has aroused my curiosity of how it works. Are there  
ruby gems to read MP4 files ?