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

Media Data Atom TypesVR MediaReservedFour bytes that must be set to 0.Additional dataA variable length field containing data pointed to by hint track sample mode entries in the data table.VR MediaNote VR Media is deprecated in the QuickTime file format. The information that follows is intendedto document existing content containing VR Media and should not be used for new development.This section describes the QuickTime VR world and node information atom containers, which can be obtainedby calling the QuickTime VR Manager routines QTVRGetVRWorld and QTVRGetNodeInfo. Those routines, aswell as a complete discussion of QuickTime VR and how your application can create QuickTime VR movies, aredescribed in detail in QuickTime VR .Many atom types contained in the VR world and node information atom containers are unique within theircontainer. For example, each has a single header atom. Most parent atoms within an atom container are uniqueas well, such as the node parent atom in the VR world atom container or the hot spot parent atom in the nodeinformation atom container. For these one-time-only atoms, the atom ID is always set to 1. Unless otherwisementioned in the descriptions of the atoms that follow, assume that the atom ID is 1.Note that many atom structures contain two version fields, majorVersion and minorVersion. The valuesof these fields correspond to the constants kQTVRMajorVersion and kQTVRMinorVersion found in theheader file QuickTimeVRFormat.h. For QuickTime 2.0 files, these values are 2 and 0.QuickTime provides a number of routines for both creating and accessing atom containers.Some of the leaf atoms within the VR world and node information atom containers contain fields that specifythe ID of string atoms that are siblings of the leaf atom. For example, the VR world header atom contains afield for the name of the scene. The string atom is a leaf atom whose atom type is kQTVRStringAtomType('vrsg'). Its atom ID is that specified by the referring leaf atom.A string atom contains a string. The structure of a string atom is defined by the QTVRStringAtom data type.typedef struct QTVRStringAtom {UInt16UInt16unsigned charstringUsage;stringLength;theString[4];2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.267