Inside Macintosh: QuickTime Components /

Chapter 10 - Derived Media Handler Components / Derived Media Handler Components Reference

Functions

Graphics Data Management

If your media handler draws media data on the screen, you need to manage your media's graphics environment. The Movie Toolbox uses a number of functions to inform you about changes to the graphics environment. The Movie Toolbox only calls these functions if you have set the handlerHasSpatial flag to 1 in the flags parameter of the MediaSetHandlerCapabilities function.

The Movie Toolbox calls your handler's MediaSetGWorld function whenever your media's graphics port or graphics device has changed. The MediaSetDimensions function allows the Movie Toolbox to inform your handler about changes to its spatial dimensions. Whenever either the movie or track matrix changes, the Movie Toolbox calls your MediaSetMatrix function. Similarly, if your media's clipping region changes, the Movie Toolbox calls your MediaSetClip function.

When it is building up a movie's image from its component tracks, the Movie Toolbox must be able to determine which tracks are transparent. The Movie Toolbox calls your MediaGetTrackOpaque function to retrieve this information about your media.

The Movie Toolbox calls your MediaGetNextBoundsChange function so that it can learn when your media will next change its display shape. When the Movie Toolbox wants to find out the shape of the region into which you draw your media, it calls your MediaGetSrcRgn function.

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Subtopics

MediaSetGWorld

MediaSetDimensions

MediaSetMatrix

MediaSetClip

MediaGetTrackOpaque

MediaGetNextBoundsChange

MediaGetSrcRgn