DXGKDDI_VIDPNTOPOLOGY_ACQUIREPATHINFO callback function (d3dkmddi.h)
The pfnAcquirePathInfo function returns a descriptor of the video present path specified by a video present source and a video present target within a particular VidPN topology.
Syntax
DXGKDDI_VIDPNTOPOLOGY_ACQUIREPATHINFO DxgkddiVidpntopologyAcquirepathinfo;
NTSTATUS DxgkddiVidpntopologyAcquirepathinfo(
[in] IN_CONST_D3DKMDT_HVIDPNTOPOLOGY hVidPnTopology,
[in] IN_CONST_D3DDDI_VIDEO_PRESENT_SOURCE_ID VidPnSourceId,
[in] IN_CONST_D3DDDI_VIDEO_PRESENT_TARGET_ID VidPnTargetId,
[out] DEREF_OUT_CONST_PPD3DKMDT_VIDPN_PRESENT_PATH ppVidPnPresentPathInfo
)
{...}
Parameters
[in] hVidPnTopology
A handle to a VidPN topology object. The display miniport driver previously obtained this handle by calling the pfnGetTopology function of the DXGK_VIDPN_INTERFACE interface.
[in] VidPnSourceId
An integer that identifies a video present source.
[in] VidPnTargetId
An integer that identifies a video present target.
[out] ppVidPnPresentPathInfo
A pointer to a variable that receives a pointer to a D3DKMDT_VIDPN_PRESENT_PATH structure that describes the requested path.
Return value
The pfnAcquirePathInfo function returns one of the following values:
| Return code | Description |
|---|---|
| STATUS_SUCCESS | The function succeeded. |
| STATUS_GRAPHICS_INVALID_VIDPN_TOPOLOGY | The handle supplied in hVidPnTopology was invalid. |
Remarks
When you have finished using the D3DKMDT_VIDPN_PRESENT_PATH structure, you must release the structure by calling pfnReleasePathInfo.
A path contains a (source, target) pair, and a topology is a collection of paths. This function returns a descriptor for the path, in a specified topology, that contains a specified (source, target) pair.
You can enumerate all the paths that belong to a VidPN topology object by calling pfnAcquireFirstPathInfo and then making a sequence of calls to pfnAcquireNextPathInfo.
VidPN source identifiers are assigned by the operating system. DxgkDdiStartDevice, implemented by the display miniport driver, returns the number N of video present sources supported by the display adapter. Then the operating system assigns identifiers 0, 1, 2, ... N - 1.
VidPN target identifiers are assigned by the display miniport driver. DxgkDdiQueryChildRelations, implemented by the display miniport driver, returns an array of DXGK_CHILD_DESCRIPTOR structures, each of which contains an identifier.
The D3DKMDT_HVIDPNTOPOLOGY data type is defined in D3dkmdt.h.
The D3DDDI_VIDEO_PRESENT_SOURCE_ID and D3DDDI_VIDEO_PRESENT_TARGET_ID data types are defined in D3dukmdt.h.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows Vista |
| Target Platform | Desktop |
| Header | d3dkmddi.h (include D3dkmddi.h) |
| IRQL | PASSIVE_LEVEL |