IDMOVideoOutputOptimizations::QueryOperationModePreferences method (mediaobj.h)
[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]
The QueryOperationModePreferences method retrieves the DMO's preferred optimization features.
Syntax
HRESULT QueryOperationModePreferences(
ULONG ulOutputStreamIndex,
DWORD *pdwRequestedCapabilities
);
Parameters
ulOutputStreamIndex
Zero-based index of an output stream on the DMO.
pdwRequestedCapabilities
Pointer to a variable that receives the DMO's requested features. The returned value is a bitwise combination of zero or more flags from the DMO_VIDEO_OUTPUT_STREAM_FLAGS enumeration.
Return value
Returns an HRESULT value. Possible values include those in the following table.
| Return code | Description |
|---|---|
|
Invalid stream index |
|
NULL pointer argument |
|
Success |
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Windows |
| Header | mediaobj.h (include Dmo.h) |
| Library | Dmoguids.lib |