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

Movie AtomsMedia AtomsFigure 2-21 (page 81) shows the layout of the media header atom.Figure 2-21The layout of a media header atomBytesMedia header atomAtom sizeType = 'mdhd'VersionFlagsCreation timeModification timeTime scaleDurationLanguageQuality4413444422Media header atoms contain the following data elements.SizeA 32-bit integer that specifies the number of bytes in this media header atom.TypeA 32-bit integer that identifies the atom type; this field must be set to 'mdhd'.VersionOne byte that specifies the version of this header atom.FlagsThree bytes of space for media header flags. Set this field to 0.Creation timeA 32-bit integer that specifies (in seconds since midnight, January 1, 1904) when the media atom wascreated. It is strongly recommended that this value should be specified using coordinated universal time(UTC).Modification timeA 32-bit integer that specifies (in seconds since midnight, January 1, 1904) when the media atom waschanged. It is strongly recommended that this value should be specified using coordinated universaltime (UTC).2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.81