QuickTime 3 Reference

Specifying a Part of a File to Import

When using certain movie import components, applications can import data from a part of a file rather than the entire file by calling the MovieImportSetOffsetAndLimit function. This function allows an application to specify a byte offset into the file at which the import operation begins and another offset, known as the limit, which indicates the last data in the file that can be imported. This function is especially useful when one file format is embedded in another; it allows an application to skip header data for the enclosing file and begin importing data at the start of the desired format.

Not all movie import components support the MovieImportSetOffsetAndLimit function. Those that do include the movie import components provided with QuickTime for the kQTFileTypeAIFF , kQTFileTypeWave , and kQTFileTypeMuLaw file types. Those that do not return the result code badComponentSelector in response to a MovieImportSetOffsetAndLimit call.