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Inside Macintosh: QuickTime /
Chapter 3 - Image Compression Manager / Image Compression Manager Reference
Image Compression Manager Functions


Working With the StdPix Function

To allow applications to have access to compressed image data as it is displayed, a new graphics function has been added to the grafProcs field of the color graphics port structure (defined by the CGrafPort data type). See Inside Macintosh: Imaging for more information about the color graphics port structure.

The StdPix function extends the current grafProcs field to support compressed data, mattes, and matrices. The new function supports pixel maps and allows you to intercept image data in compressed form before it is decompressed and displayed. For example, you can use the StdPix function to collect compressed image data that is to be processed and printed. In addition, your application can call the StdPix function directly.

The replaced grafProcs field is referred to in the original QuickDraw documentation as the newProc1 field. The standard handler is called StdPix, and you obtain its address by calling QuickDraw's SetStdCProcs routine. Alternatively, your application can call the StdPix function directly, using the interface described here. Your application can intercept the low-level grafProcs drawing routines just as it would any of the other routines, except that you must call SetStdCProcs to gain access to the standard grafProcs handler.

Note
QuickDraw's CopyDeepMask function uses the StdPix function
if QuickTime is present.
See Inside Macintosh: Imaging for more information about the QuickDraw low-level drawing routines, the SetStdCProcs routine, the QDProcs structure, and the CopyDeepMask routine.

To work with the control information associated with a compressed image, you can use the SetCompressedPixMapInfo and GetCompressedPixMapInfo functions (described on page 3-133 and page 3-135, respectively).


Subtopics
StdPix
SetCompressedPixMapInfo
GetCompressedPixMapInfo

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© Apple Computer, Inc.
6 JUL 1996