Inside Macintosh: QuickTime Components /

Chapter 5 - Sequence Grabber Components / Sequence Grabber Components Reference

Application-Defined Functions /

MyGrabCompressCompleteFunction

The sequence grabber calls your grab-compress-complete function when it
is working with a video digitizer that supports compressed source data. Your grab-compress-complete function is responsible for determining whether the current compressed frame has been completely captured and compressed, essentially combining your grab-complete, compress, and compress-complete functions into one function.

Your function must support the following interface:

pascal ComponentResult MyGrabCompressCompleteFunction 
                                             (SGChannel c,
                                              Boolean *done, 
                                              SGCompressInfo *ci,
                                              TimeRecord *tr,
                                              long refCon);

c

Identifies the channel for this operation.

done

Contains a pointer to a Boolean value. Set this Boolean value to indicate whether you are finished. Set it to true when you are done; set it to false if the operation is incomplete.

ci

Contains a pointer to a compression information structure. When the operation is complete, fill in this structure with information about the compression operation. The format and content of this structure are discussed earlier in this chapter, beginning on page 5-20.

tr

Contains a pointer to a time record. When the operation is complete, fill in this structure with information indicating when the frame was grabbed. The format and content of this structure are discussed in the chapter "Movie Toolbox" in Inside Macintosh: QuickTime.

refCon

Contains a reference constant value. You can set this value by calling the SGSetChannelRefCon function, which is described on page 5-64.

RESULT CODE

cantDoThatInCurrentMode

-9402

Request invalid in current mode

SEE ALSO

Your grab-compress-complete function may use the sequence
grabber's SGGrabCompressComplete function to support the default behavior. SGGrabCompressComplete is discussed beginning on page 5-105.

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