IWMEncProfile2::AddAudience

The AddAudience method adds a new audience to the current profile.

Syntax

HRESULT AddAudience(
  long  lBitrate,
  IWMEncAudienceObj**  ppAudience
);

Parameters

lBitrate

[in]  long containing the bit rate for the new audience, in bits per second (bps).

ppAudience

[out]  Pointer to a pointer to an IWMEncAudienceObj interface containing the new audience.

Return Values

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

Return code	Number	Description
E_POINTER	0x80004003	The indirect pointer to the audience is NULL.

Remarks

An audience is a collection of settings specifying the bit rates for each stream, and additional settings depending on the types of streams in the profile. Profiles that use constant bit rate (CBR) mode can contain multiple audiences.

Example Code

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

    HRESULT hr;
    IWMEncProfile2* pPro2;
    IWMEncAudienceObj* pAudnc;
    long lAudCount;
    int i;

    // Initialize the COM library and retrieve a pointer to an IWMEncProfile2 interface.
    hr = CoInitialize(NULL);

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

    // Verify profile settings immediately as they are set.
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->put_ValidateMode(VARIANT_TRUE);
    }

    // Provide a name and description.
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->put_ProfileName(CComBSTR("Sample MBR Profile"));
    }
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->put_ProfileDescription(CComBSTR("A video profile with three audiences"));
    }

    // Specify video content.
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->put_ContentType(16);
    }

    // Specify constant bit rate (CBR) mode.
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->put_VBRMode(WMENC_VIDEO, 0, WMENC_PVM_NONE);
    }

    // Add audiences for 200, 400, and 600 Kbps.
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->AddAudience(200000, &pAudnc);
    }
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->AddAudience(400000, &pAudnc);
    }
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->AddAudience(600000, &pAudnc);
    }
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->get_AudienceCount(&lAudCount);
    }

    // Create an audience object then loop through all of the audiences
    // in the current profile, making the same changes to each audience.
    for (i = 0; i < lAudCount; i++)
    {
        if ( SUCCEEDED( hr ) )
        {
            hr = pPro2->get_Audience(i, &pAudnc);
        }
        // The Windows Media 9 codec is used by default, but you can change
        // it as follows. Be sure to make this change for each audience.
        if ( SUCCEEDED( hr ) )
        {
            hr = pAudnc->put_VideoCodec(0, 2);
        }

        // Make the video output size match the input size by setting height and width to 0.
        if ( SUCCEEDED( hr ) )
        {
            hr = pAudnc->put_VideoHeight(0, 0);
        }
        if ( SUCCEEDED( hr ) )
        {
            hr = pAudnc->put_VideoWidth(0, 0);
        }

        // Change the buffer size to 5 seconds. By default, the end user's default setting is used.
        if ( SUCCEEDED( hr ) )
        {
            hr = pAudnc->put_VideoBufferSize(0, 5000);
        }
    }

    // Change the video image sharpness for the first audience only.
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->get_Audience(0, &pAudnc);
    }
    if ( SUCCEEDED( hr ) )
    {
        hr = pAudnc->put_VideoImageSharpness(0, 70);
    }

    // Validate the settings to make sure the profile has no errors.
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->Validate();
    }

    // Save the profile to a .prx file.
    if ( SUCCEEDED( hr ) )
    {
        hr = pPro2->SaveToFile(CComBSTR("C:\\Program Files\\Windows Media Components\\Encoder\\Profiles\\CPPprofile.prx"));
    }

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

Requirements

Header: wmencode.h

Library: wmenc.exe

See Also

• IWMEncProfile2 Interface
• Working with Profiles