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KSDEVICE_DESCRIPTOR structure (ks.h)

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The KSDEVICE_DESCRIPTOR structure describes the characteristics of a particular device.

Syntax

typedef struct _KSDEVICE_DESCRIPTOR {
  const KSDEVICE_DISPATCH   *Dispatch;
  ULONG                     FilterDescriptorsCount;
  const KSFILTER_DESCRIPTOR const * * FilterDescriptors;
  ULONG                     Version;
  ULONG                     Flags;
  PVOID                     Alignment;
} KSDEVICE_DESCRIPTOR, *PKSDEVICE_DESCRIPTOR;

Members

Dispatch

A pointer to the client dispatch table for this device. This dispatch table contains client dispatch functions for PNP messages such as Add, Start, Stop, Remove. Clients are not required to supply a dispatch table unless they want to receive callbacks for the PNP messages described in the dispatch table. Any member of the dispatch table can be NULL to indicate that the client does not want to receive notification for that particular message. For more information, see KSDEVICE_DISPATCH.

FilterDescriptorsCount

This member contains the number of filter descriptors for this device that will be provided in the FilterDescriptors member. Zero is a legal value for this member; clients can create filter factories dynamically with the KsCreateFilterFactory function instead of statically describing them in the device descriptor.

FilterDescriptors

A pointer to an array of filter descriptors that describe filters that can be created by this device. This member may be NULL if FilterDescriptorsCount is zero. For more information, see KSFILTER_DESCRIPTOR.

Version

A value of type ULONG. This should be one and only one of the values in the following table, or set to zero if writing a pre-version 0x100 driver.

Value Description
KSDEVICE_DESCRIPTOR_VERSION Indicates support of the AVStrMiniDeviceQueryInterface dispatch of KSDEVICE_DISPATCH.
KSDEVICE_DESCRIPTOR_VERSION_2 Indicates support of the Flags member of KSDEVICE_DESCRIPTOR.

Flags

A value of type ULONG. There is only one flag currently defined.

Flag Description
KSDEVICE_FLAG_ENABLE_REMOTE_WAKEUP Indicates that the device supports remote wakeup.

Alignment

Remarks

Most often, this structure is used in conjunction with KsInitializeDriver in the client's DriverEntry function to initialize the device. This structure is also used to manually initialize or create devices with the KsInitializeDevice and KsCreateDevice functions.

If you set Version to KSDEVICE_DESCRIPTOR_VERSION_2 and run your driver on an early version of AVStream that does not support Flags, all flags will be considered to be zero.

Similarly, using an earlier version descriptor on later versions of AVStream causes no flags to be specified.

Requirements

Requirement Value
Header ks.h (include Ks.h)

See also

KSDEVICE_DISPATCH

KSFILTER_DESCRIPTOR

KsCreateDevice

KsInitializeDevice

KsInitializeDriver