KSDEVICE_DESCRIPTOR structure (ks.h)
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) |