Technical Q&As

QTICM 06 - New Monitor Related Playback Calls (1-May-95)

Three additional calls--GDHasScale, GDGetScale, GDSetScale--allow applications to zoom a monitor. They are considered low-level calls (comparable to SetEntries) that should be used only when playing back QuickTime movies in a controlled environment with no user interaction. Also, because this capability is not present on all machines, applications should not depend on its availability.

The new calls provide a standard way for developers to access the resizing abilities of a user's monitor for playback. Effectively, this allows you to have full screen Cinepak playback on low-end Macintosh computers.

Hardware 200 percent resize is currently available only on the Macintosh LC II, IIvx, IIvi, Performa 400, Performa 600, and Color Classic in 16-bit (thousands of colors) display mode on the 12-inch (512 x 384 pixels) monitors. In the future, other graphic devices may take advantage of it.

To implement this functionality, the Image Compression Manager actually makes calls to the video driver for the given device. Video card manufacturers interested in supporting this functionality in their cards should send an AppleLink to DEVSUPPORT (Internet: DEVSUPPORT@applelink.apple.com)
See also: The QuickTime Technote (QT4).

Technical Q&As
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