QuickTime 4 Reference

Save-and-Restore Component Routines

If you are writing movie data exchange components, and would like your components' settings to be saved and restored, you need to implement two additional component routines in order to allow your components to have their settings saved and restored. A component's settings are stored in a QuickTime QT atom container. The data stored in the QT atom container is private to the particular component but should be stored so that it is possible to read the data on all platforms supported by QuickTime, thus allowing the same settings to be used anywhere. ( "Settings Container Format and Guidelines" provides further details.) For each type of movie data exchange component, there is one routine to return a QT atom container holding the settings and another routine to configure the component from previously-saved settings. For more information about QT atom containers, see the QuickTime Atom documentation.

Import component developers need to implement the MovieImportGetSettingsAsAtomContainer and MovieImportSetSettingsFromAtomContainer routines. For MovieImportGetSettingsAsAtomContainer , the component should allocate a new QT atom container, stuff current settings into it, and return it to the caller. For MovieImportSetSettingsFromAtomContainer , the component should accept a QT atom container, extract the settings in which it is interested, and change its internal state.

Export component developers need to implement the MovieExportGetSettingsAsAtomContainer and MovieExportSetSettingsFromAtomContainer routines. Like import components, the component's MovieExportGetSettingsAsAtomContainer routine allocates and returns a QT atom container holding the component's settings. For MovieExportSetSettingsFromAtomContainer , the component accepts a QT atom container, extracts the settings, and updates its internal state.