Quicktime File Format (2012-08-14).pdf

Media Data Atom TypesMovie MediaFor object movies containing alternate view states, alternate view states are stored as separate object imagearrays that immediately follow the preceding view state in the object image track. Each state does not needto contain the same number of frames. However, the total movie time of each view state in an object nodemust be the same.Movie MediaMovie media is used to encapsulate embedded movies within QuickTime movies. This feature is available inQuickTime 4.1.Movie Sample DescriptionThe movie media doesn’t have a unique sample description. It uses the minimum sample description, whichis SampleDescriptionRecord.Movie Media Sample FormatEach sample in the movie media is a QuickTime atom container. All root-level atoms and their contents areenumerated in the following list. Note that the contents of all atoms are stored in big-endian format.kMovieMediaDataReferenceA data reference type and a data reference. The data reference type is stored as an OSType at the startof the atom. The data reference is stored following the data reference type. If the data reference type isURL and the data reference is for a movie on the Apple website, the contents of the atom would be urlhttp://www.apple.com/foo.mov.There may be more than one atom of this type. The first atom of this type should have an atom ID of 1.Additional data references should be numbered sequentially.kMovieMediaDefaultDataReferenceIDThis atom contains a QTAtomID that indicates the ID of the data reference to use when instantiating theembedded movie for this sample. If this atom is not present, the data reference with an ID of 1 is used.kMovieMediaSlaveTimeA Boolean that indicates whether or not the TimeBase of the embedded movie should be slaved to theTimeBase of the parent movie. If the TimeBase is slaved, the embedded movie’s zero time will correspondto the start time of its movie media sample. Further, the playback rate of the embedded movie will alwaysbe the same as the parent movie’s. If the TimeBase is not slaved, the embedded movie will default to arate of 0, and a default time of whatever default time value it instantiated with (which may not be 0). Ifthe TimeBase is not slaved, the embedded movie can be played by either including an AutoPlay atom2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.310