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

Media Data Atom TypesPanorama TrackshotSpotNumFramesXThe number of frames into which the panoramic image is diced horizontally for the hot spot image track.hotSpotNumFramesYThe number of frames into which the panoramic image is diced vertically for the hot spot image track.flagsA set of panorama flags. kQTVRPanoFlagHorizontal has been superseded by the panoType field. Itis used only when the panoType field is nil to indicate a horizontally-oriented cylindrical panorama.kQTVRPanoFlagAlwaysWrap is set if the panorama should wrap horizontally, regardless of whether ornot the pan range is 360 degrees. Note that these flags are currently supported only under OS X.panoTypeAn OSType describing the type of panorama. Types supported are:kQTVRHorizontalCylinderkQTVRVerticalCylinderkQTVRCubereserved2Reserved. This field must be 0.Important A new flag has been added to the flags field of the QTVRPanoSampleAtom data structure. Thisflag controls how panoramas wrap horizontally. If kQTVRPanoFlagAlwaysWrap is set, then the panoramawraps horizontally, regardless of the number of degrees in the panorama. If the flag is not set, then the panoramawraps only when the panorama range is 360 degrees. This is the default behavior.The minimum and maximum values in the panorama sample atom describe the physical limits of the panoramicimage. QuickTime VR allows you to set further constraints on what portion of the image a user can see bycalling the QTVRSetConstraints routine. You can also preset image constraints by adding constraint atomsto the panorama sample atom container. The three constraint atom types are kQTVRPanConstraintAtomType,kQTVRTiltConstraintAtomType, and kQTVRFOVConstraintAtomType. Each of these atom types sharea common structure defined by the QTVRAngleRangeAtom data type:typedef struct QTVRAngleRangeAtom {Float32Float32minimumAngle;maximumAngle;} QTVRAngleRangeAtom, *QTVRAngleRangeAtomPtr;Field descriptions2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.292