DxApi function

The DxApi function accepts commands from the hardware decoder's video capture driver to access the DxApi interface functions that are implemented in a video miniport driver.

Parameters

• dwFunctionNum indicates the behavior of the DxApi function (function identifier). See the Remarks section for the list of function identifiers.

• lpvInBuffer points to the input buffer.

• cbInBuffer indicates the size in bytes of the input buffer.

• lpvOutBuffer points to the output buffer.

• cbOutBuffer indicates the size in bytes of the output buffer.

Returns

DxApi returns the number of bytes actually written to the output buffer.

Remarks

DxApi accepts a function identifier (dwFunctionNum), an input buffer (lpvInBuffer) and its size (cbInBuffer), and an output buffer (lpvOutBuffer) and its size (cbOutBuffer). The behavior of the function and the size and format of the input and output buffers depend on the specified function identifier. The return value is the number of actual bytes written into the output buffer.

The following function identifiers are defined for the DxApi function in the ddkmapi.h header file:

• DD_DXAPI_ADDVPCAPTUREBUFFER
• DD_DXAPI_CLOSEHANDLE
• DD_DXAPI_FLIP_OVERLAY
• DD_DXAPI_FLIP_VP
• DD_DXAPI_FLUSHVPCAPTUREBUFFERS
• DD_DXAPI_GET_CURRENT_VP_AUTOFLIP_SURFACE
• DD_DXAPI_GET_LAST_VP_AUTOFLIP_SURFACE
• DD_DXAPI_GET_POLARITY
• DD_DXAPI_GET_SURFACE_STATE
• DD_DXAPI_GET_VP_FIELD_NUMBER
• DD_DXAPI_GETKERNELCAPS
• DD_DXAPI_GETVERSIONNUMBER
• DD_DXAPI_LOCK
• DD_DXAPI_OPENDIRECTDRAW
• DD_DXAPI_OPENSURFACE
• DD_DXAPI_OPENVIDEOPORT
• DD_DXAPI_OPENVPCAPTUREDEVICE
• DD_DXAPI_REGISTER_CALLBACK
• DD_DXAPI_SET_SURFACE_STATE
• DD_DXAPI_SET_VP_FIELD_NUMBER
• DD_DXAPI_SET_VP_SKIP_FIELD
• DD_DXAPI_UNREGISTER_CALLBACK