|This is retired content. This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This content may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist.|
Like other types of surfaces, you can create overlay flipping chains. After creating a flipping chain of overlays, call the IDirectDrawSurface5::Flipmethod to flip between them. For more information, see Flipping Surfaces.
Software decoders displaying video with overlay surfaces can use the DDFLIP_ODD and DDFLIP_EVEN flags when calling the Flipmethod to use features that reduce motion artifacts. If the driver supports odd-even flipping, the DDCAPS2_CANFLIPODDEVEN flag will be set in the DDCAPSstructure after retrieving driver capabilities. If DDCAPS2_CANFLIPODDEVEN is set, you can include the DDOVER_BOB flag when calling the IDirectDrawSurface5::UpdateOverlaymethod to inform the driver that you want it to use the "Bob" algorithm to minimize motion artifacts. Later, when you call Flipwith the DDFLIP_ODD or DDFLIP_EVEN flag, the driver will automatically adjust the overlay source rectangle to compensate for jittering artifacts.
If the driver doesn't set the DDCAPS2_CANFLIPODDEVEN flag when you retrieve hardware capabilities, UpdateOverlaywill fail if you specify the DDOVER_BOB flag.
For more information about the Bob algorithm, see Solutions to Common Video Artifacts.
Last updated on Tuesday, May 18, 2004