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This section summarizes the public IOCTL_VIDEO_XXX requests that video miniport drivers handle. These IOCTL requests are defined in ntddvdeo.h.
IOCTL_VIDEO_XXX requests are generally described as either modal or nonmodal. However, there are a few IOCTLs that are both modal and nonmodal. An IOCTL is modal if that operation is valid only with a mode. After a set-mode operation is performed, the state associated with a modal IOCTL is destroyed or reinitialized. A nonmodal IOCTL preserves its state across set-mode operations.
Every video miniport driver must provide support for at least the following requests:
IOCTL_VIDEO_UNMAP_VIDEO_MEMORY
IOCTL_VIDEO_QUERY_NUM_AVAIL_MODES
IOCTL_VIDEO_QUERY_CURRENT_MODE
Depending on the adapter features, a miniport driver can be required to support additional IOCTL_VIDEO_XXX requests, while support for others is optional.
For information, see Display Drivers.