QuickTime 4 Reference

Single Fork Preview Support

QuickTime has always supported the display of file previews using the StandardGetFilePreview function. The format for storing these file previews has always been based on Macintosh resources. However, this approach does not work for files created or viewed on operating systems that do not support resource forks. You can now use the StandardGetFilePreview function to display previews that are stored in the data fork of a file. QuickTime does not, however, provide support for creating previews that are stored in the data fork of a file. Applications must create these previews themselves.