Inside Macintosh: QuickTime Components /

Chapter 6 - Sequence Grabber Channel Components / Sequence Grabber Channel Components Reference

Functions / Configuration Functions for Video Channel Components

SGGetUseScreenBuffer

The SGGetUseScreenBuffer function allows the sequence grabber to determine whether your video channel is allowed to use an offscreen buffer.

pascal ComponentResult SGGetUseScreenBuffer (SGChannel c, 
                                       Boolean *useScreenBuffer);

c

Identifies the channel connection for this operation.

useScreenBuffer

Contains a pointer to a Boolean value. Set this field to true if your channel draws directly to the screen. Set it to false if your channel can use an offscreen buffer. If your channel cannot work with offscreen buffers, ignore this value.

DESCRIPTION

By default, video channels draw directly to the screen. The sequence grabber can direct a channel to draw to an offscreen buffer by calling your SGSetUseScreenBuffer function. If the channels can work offscreen, it then allocates and draws to an offscreen buffer.

SEE ALSO

You can allow a channel to draw offscreen by calling the SGSetUseScreenBuffer function, which is described in the previous section.

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