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Inside Macintosh: QuickTime /
Chapter 3 - Image Compression Manager / Using the Image Compression Manager


Getting Information About Compressors and Compressed Data

Use the Gestalt environmental selector gestaltCompressionMgr to determine whether the Image Compression Manager is available. Gestalt returns a 32-bit value indicating the version of the Image Compression Manager that is installed. This return value is formatted in the same way as the value returned by the CodecManagerVersion function (described on page 3-57), and it contains the version number specified as an integer value.

#define gestaltCompressionMgr 'icmp'
The Image Compression Manager provides a number of functions that allow your application to obtain information about the facilities available for image compression or about compressed images. Your application may use some of these functions to select a specific compressor or decompressor for a given operation or to determine how much memory to allocate to receive a decompressed image. In addition, your application may use some of these functions to determine the capabilities of the components that are available on the user's computer system. You can then condition the options your program makes available to the user based on the user's system configuration.
See "Getting Information About Compressor Components," which begins on page 3-56, and "Getting Information About Compressed Data," which begins on page 3-62, for detailed descriptions of these functions.


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© Apple Computer, Inc.
6 JUL 1996