#include "ltmm.h"
C Syntax |
HRESULT IltmmPlay_GetPreferredFilter(pPlay, FilterType, pVal) |
C++ Syntax |
HRESULT GetPreferredFilter(FilterType, pVal) |
IltmmPlay *pPlay; |
pointer to an interface |
long FilterType |
value to a filter type |
BSTR *pVal; |
pointer to a string |
Retrieves the preferred filter display name set using IltmmPlay::SetPreferredFilter.
Parameter |
Description |
pPlay |
Pointer to an IltmmPlay interface. |
FilterType |
Value that indicate the filter type. For a list of possible values, refer to lltmmPlay_PreferredFilter Constants. |
pVal |
Pointer to a string to be updated with the filter display name. |
S_OK |
The function was successful. |
<> S_OK |
An error occurred. Refer to the Error Codes or the HRESULT error codes in the DirectShow documentation. |
This method can be used to determine whether a preferred filter has been set by IltmmPlay::SetPreferredFilter. It returns either NULL (if no preferred filter has been set), or a display name indicating the preferred filter.
A display name uniquely identifies the filter. Display names have the following format:
@device:sw:GUID\GUID
For example, the display name for the LEAD MPEG2 Transport Demultiplexer is:
@device:sw:{083863F1-70DE-11D0-BD40-00A0C911CE86}\{E2B7DF1A-38C5-11D5-91F6-00104BDB8FF9}
Note that there is a single backslash between the two GUIDs. But if you enter this as a C/C++ string, you would need to use two backslashes since '\' is an escape character in C/C++ strings.
If the method succeeds, the caller must free the returned string by calling the SysFreeString function.
A list of display names for common filters can be found in ltmmFilter Constants.
Refer to IltmmPlay::SetPreferredFilter for more information on filter display names.
Required DLLs and Libraries
LTMM For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application. |
Win32, x64
Elements: |
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Topics: |
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For a C++ example, refer to IltmmPlay::SetPreferredFilter Example for C++.
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