NOTE: This Technical Q&A has been retired. Please see the Technical Q&As page for current documentation.

Technical Q&A QTW84
Customizing QuickTime Components

Q I've written a custom movie controller component that allows me to trap MCDoAction() calls. Do you know if there is a way to trap other calls beyond the MCDoAction() calls? In particular, I'm interested in the information given in the OpenMovieFile() call. What I'm looking for is the name of the QT file that is being used for a particular movie controller. Is there a way of getting the name of that file?

A Your custom component registers itself as being a movie controller -- that is why it receives MCDoAction() requests. Much of QTW is hard-coded and can't be overridden, though. You can't trap the OpenMovieFile() call, but you can write a data handler component that is responsible for loading data and thus presumably would be privy to the filename. The QT 2.0 SDK has a sample data handler component (MMIO_DH).

For a better idea of what components are overridable, launch the QTW Control Panel and click on More|Components. All external components can be found by Type and Subtype. Components not listed (such as sound decompressors) are hard-coded internally and cannot be overridden.

[Sep 27 1996]


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