Inside Macintosh: QuickTime Components /

Chapter 5 - Sequence Grabber Components / Sequence Grabber Components Reference

Sequence Grabber Component Functions / Configuring Sequence Grabber Components

SGSetGWorld

The SGSetGWorld function allows you to establish the graphics port and device for a sequence grabber component. The sequence grabber component displays the recorded or previewed data in this graphics world.

pascal ComponentResult SGSetGWorld (SeqGrabComponent s, 
                                    CGrafPtr gp, GDHandle gd);

s

Specifies the component instance that identifies your connection to the sequence grabber component. You obtain this value from the Component Manager's OpenDefaultComponent or OpenComponent function.

gp

Specifies the destination graphics port. The specified graphics port must be a color graphics port. Set this parameter to nil to use the current graphics port.

gd

Specifies the destination graphics device. Set this parameter to nil to use the current device. If the gp parameter specifies a graphics world, set this parameter to nil to use that graphics world's graphics device.

DESCRIPTION

You must call this function if you are working with any channels that collect visual data. If you are working only with data that has no visual representation, you do not need to call this function. The sequence grabber component performs this operation implicitly when you call the SGInitialize function (described on page 5-23), and the component uses your application's current graphics port.

You cannot call this function during a record or preview operation or after you have prepared the sequence grabber component for a record or preview operation (by calling the SGPrepare function, which is described on page 5-40).

IMPORTANT

The window in which the sequence grabber is to draw video frames as defined by SGSetGWorld must be visible before you call the SGPrepare function. Otherwise, the sequence grabber does not display the frames properly. For details, see the discussion of SGPrepare beginning on page 5-40.

RESULT CODE

cantDoThatInCurrentMode

-9402

Request invalid in current mode

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