Movie atom ('moov')
An atom that specifies the information that defines a movie.
Overview
You use movie atoms to specify the information that defines a movie — that is, the information that allows your application to interpret the sample data that is stored elsewhere. The movie atom usually contains a movie header atom, which defines the time scale and duration information for the entire movie, as well as its display characteristics. Existing movies may contain a movie profile atom, which summarizes the main features of the movie, such as the necessary codecs and maximum bit rate. In addition, the movie atom contains a track atom for each track in the movie.
The movie atom has an atom type of 'moov'. It contains other types of atoms, including at least one of three possible atoms—the movie header atom ('mvhd'), the compressed movie atom ('cmov'), or a reference movie atom ('rmra'). An uncompressed movie atom can contain both a movie header atom and a reference movie atom, but it must contain at least one of the two. It can also contain several other atoms, such as a clipping atom ('clip'), one or more track atoms ('trak'), a color table atom ('ctab'), and a user data atom ('udta').
Compressed movie atoms and reference movie atoms are discussed separately. This section describes normal uncompressed movie atoms.
The layout of movie atom is as follows.
Data | Type |
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4 bytes | |
Type = | 4 bytes |
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One or more Track_atoms |
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‡ denotes required atom.