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Chapter 5 - Sequence Grabber Components / Sequence Grabber Components Reference

Sequence Grabber Component Functions / Utility Functions for Video Channel Callback Functions

SGAddFrame

The SGAddFrame function provides the default behavior for your add-frame function.

pascal ComponentResult SGAddFrame (SGChannel c, short bufferNum,
                                    TimeValue atTime, 
                                    TimeScale scale, 
                                    const SGCompressInfo *ci);

c

Specifies the reference that identifies the channel for this operation. The sequence grabber component provides this value to your add-frame function.

bufferNum

Identifies the buffer. The sequence grabber component provides this value to your add-frame function.

atTime

Specifies the time at which the frame was captured, in the time
scale specified by the scale parameter. The sequence grabber component provides this value to your add-frame function. Your add-frame function can change this value before calling the SGAddFrame function. You can determine the duration of a frame by subtracting its capture time from the capture time of the next frame in the sequence.

scale

Specifies the time scale of the movie. The sequence grabber component provides this value to your add-frame function.

ci

Contains a pointer to a compression information structure (defined by the SGCompressInfo data type). This structure contains information describing the compression characteristics of the image to be added to the movie. See "The Compression Information Structure" beginning on page 5-20 for a description of this structure. The sequence grabber component provides this structure to your add-frame function.

SPECIAL CONSIDERATIONS

You should call the SGAddFrame function only from your add-frame function. If you call it at any other time, results are unpredictable.

RESULT CODES

cantDoThatInCurrentMode

-9402

Request invalid in current mode

Memory Manager errors

SEE ALSO

See "Application-Defined Functions," which begins on page 5-107, for information about add-frame functions.