How can I learn how multimedia file formats work?

Question

I have always been a bit puzzled about how audio/video file formats work, and how the extension of a media file (e.g. mp4) doesn't always tell the whole story about what media formats the file contains and how it is encoded. I am starting to learn about the existence of container formats and codecs, and would like to learn this hands-on by looking at some actual media files.

A while back a friend showed me a program that can inspect a media file and draw a diagram of what is contained in the file. I remember these diagrams looked a bit like flowcharts. Does this ring a bell for anyone?

I am also interested if anyone has other recommendations for other good ways to learn how multimedia file formats work.

Answer 1

• Get the GSpot tool for windows to start with.
• Then, read up the Wikipedia Container format page and its links
• Gizmodo article: Giz Explains: Every Video Format You Need to Know
• VLC will play almost any format you throw at it
  • it has a good Wiki to search through too
• another reference

Answer 2

The program you mean is GraphEdit/GraphStudio.

Wikipedia is good for learning about this sort of thing:

• Comparison of video codecs
• Container formats

Generally, multimedia files are composed of encoded video stored inside a container format.

But after that, when it comes to playing the file, the question becomes all tangled up with how the OS actually turns that into an image on screen. Then you are looking at multimedia frameworks, which is where your filter graph diagram comes in.