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

Movie AtomsTrack AtomsFlagsThree bytes that are reserved for the track header flags. These flags indicate how the track is used in themovie. The following flags are valid (all flags are enabled when set to 1).Track enabledIndicates that the track is enabled. Flag value is 0x0001.Track in movieIndicates that the track is used in the movie. Flag value is 0x0002.Track in previewIndicates that the track is used in the movie’s preview. Flag value is 0x0004.Track in posterIndicates that the track is used in the movie’s poster. Flag value is 0x0008.Creation timeA 32-bit integer that indicates the calendar date and time (expressed in seconds since midnight, January1, 1904) when the track header was created. It is strongly recommended that this value should be specifiedusing coordinated universal time (UTC).Modification timeA 32-bit integer that indicates the calendar date and time (expressed in seconds since midnight, January1, 1904) when the track header was changed. It is strongly recommended that this value should bespecified using coordinated universal time (UTC).Track IDA 32-bit integer that uniquely identifies the track. The value 0 cannot be used.ReservedA 32-bit integer that is reserved for use by Apple. Set this field to 0.DurationA time value that indicates the duration of this track (in the movie’s time coordinate system). Note thatthis property is derived from the track’s edits. The value of this field is equal to the sum of the durationsof all of the track’s edits. If there is no edit list, then the duration is the sum of the sample durations,converted into the movie timescale.ReservedAn 8-byte value that is reserved for use by Apple. Set this field to 0.LayerA 16-bit integer that indicates this track’s spatial priority in its movie. The QuickTime Movie Toolbox usesthis value to determine how tracks overlay one another. Tracks with lower layer values are displayed infront of tracks with higher layer values.2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.59