Take the 2-minute tour ×
Video Production Stack Exchange is a question and answer site for engineers, producers, editors, and enthusiasts spanning the fields of video, and media creation. It's 100% free, no registration required.

What is the purpose of Media Atom 'flags' within the QuickTime videos, I see for the most part they are set to zero but what does this achieve?

Documentation I am reading is the following: https://developer.apple.com/library/mac/documentation/QuickTime/qtff/QTFFChap2/qtff2.html

share|improve this question

2 Answers 2

They are a type of metadata specific to the QuickTime container. They can contain all kinds of extra information for the video player to read out and use.

QuickTime movie atoms have an atom type of 'moov'. These atoms act as a container for the information that describes a movie’s data. This information, or metadata, is stored in a number of different types of atoms. Generally speaking, only metadata is stored in a movie atom. Sample data for the movie, such as audio or video samples, are referenced in the movie atom, but are not contained in it.

share|improve this answer

The Media Atom object does not have a Flags field, but the Media Header Atoms does:

Flags - Three bytes of space for future movie header flags.

In which case it's basically say, these values are reserved for future use, and presently are just byte alignment packing.

In most RFC's these area's are called Reserved as compared to flags.

This would explain why they are zero, as by the spec, they should be set zero, so in the future none zero value can be interpreted to mean "something".

If I'm mistaken the section you refering let me know.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.