IWMEncAudienceObj::put_Property

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The put_Property method specifies the value of a named property for a particular stream in the current audience.

Syntax

HRESULT put_Property(
  WMENC_SOURCE_TYPE  enumSrcType,
  short  iRenderSiteIndex,
  BSTR  bstrProperty,
  VARIANT  varProperty
);

Parameters

enumSrcType

[in]  Member of a WMENC_SOURCE_TYPE enumeration type identifying the media stream type.

iRenderSiteIndex

[in]  short containing the audience stream index. Because an audience can only contain one stream of each type, iRenderSiteIndex must be zero.

bstrProperty

[in]  BSTR containing the property. Currently the only properties supported are "BufferWindow" for HTML (WMENC_FILETRANSFER) streams, and "DeviceConformanceTarget" for video.

varProperty

[in]  VARIANT that indicates the property value.

Return Values

If the method succeeds, it returns S_OK. If it fails, it supports the IErrorInfo interface and returns an HRESULT error code.

Example Code

// Include libraries.
#include <windows.h>
#include <atlbase.h>
#include <comdef.h>
#include "C:\WMSDK\WMEncSDK9\include\wmencode.h"

    // Declare variables.
    HRESULT hr;
    IWMEncoder* pEncoder;
    IWMEncProfileCollection* pProColl;
    IWMEncProfile* pPro;

    IWMEncProfile2* pPro2;
    IWMEncAudienceObj* pAudnc;

    // Initialize the COM library and retrieve a pointer to an IWMEncoder interface.
    hr = CoInitialize(NULL);
    if ( SUCCEEDED( hr ) )
    {
        hr = CoCreateInstance(CLSID_WMEncoder,
            NULL,
            CLSCTX_INPROC_SERVER,
            IID_IWMEncoder,
            (void**) &pEncoder);
    }

    // Retrieve a specific profile.
    if ( SUCCEEDED( hr ) )
    {
        hr = pEncoder->get_ProfileCollection(&pProColl);
    }
    if ( SUCCEEDED( hr ) )
    {
        hr = pProColl->Item(11, &pPro);
    }

    if ( SUCCEEDED( hr ) )
    {
        hr = CoCreateInstance(CLSID_WMEncProfile2,
            NULL,
            CLSCTX_INPROC_SERVER,
            IID_IWMEncProfile2,
            (void**) &pPro2);
    }

    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->LoadFromIWMProfile(pPro);
    }

    // Retrieve the first audience in the profile.
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->get_Audience(0, &pAudnc);
    }

    // Specify the value for the file transfer stream's preroll.
    CComVariant vStreamBuffer = 5000;  // 5 seconds.
    if ( SUCCEEDED( hr ) )
    {
        hr = pAudnc->put_Property(WMENC_FILETRANSFER, 0, CComBSTR("BufferWindow"), vStreamBuffer);
    }

    // Release pointers.
    if ( pAudnc )
    {
        pAudnc->Release();
        pAudnc = NULL;
    }
    if ( pPro2 )
    {
        pPro2->Release();
        pPro2 = NULL;
    }

Requirements

Header: wmencode.h

Library: wmenc.exe

See Also