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IWMDMDevice::GetFormatSupport

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The GetFormatSupport method retrieves all the formats supported by the device, including codecs and file formats.

Syntax

HRESULT GetFormatSupport(_WAVEFORMATEX**ppFormatEx,UINT*pnFormatCount,LPWSTR**pppwszMimeType,UINT*pnMimeTypeCount);

Parameters

ppFormatEx

[out]  Pointer to an array of _WAVEFORMATEX structures specifying information about codecs and bit rates supported by the device. Windows Media Device Manager allocates the memory for this parameter; the caller must free it using CoTaskMemFree.

pnFormatCount

[out]  Pointer to the number of elements in the ppFormatEx array.

pppwszMimeType

[out]  Pointer to an array describing file formats and digital rights management schemes supported by the device. Windows Media Device Manager allocates the memory for this parameter; the caller must free it using CoTaskMemFree.

pnMimeTypeCount

[out]  Pointer to the number of elements in the pppwszMimeType array.

Return Values

The method returns an HRESULT. All the interface methods in Windows Media Device Manager can return any of the following classes of error codes:

  • Standard COM error codes
  • Windows error codes converted to HRESULT values
  • Windows Media Device Manager error codes

For an extenstive list of possible error codes, see Error Codes.

Possible values include, but are not limited to, those in the following table.

Return code Description
S_OK The method succeeded.
E_OUTOFMEMORY Insufficient memory resources to allocate memory for ppFormatEx or pppwszMimeType.
E_INVALIDARG A parameter is invalid or a NULL pointer.
E_FAIL An unspecified error occurred.

Remarks

The recommended way to retrieve device-supported formats is IWMDMDevice3::GetFormatCapability.

Example Code

The following C++ function retrieves various device capabilities.

// Function to print out device caps for a device that supports
// only IWMDMDevice.
void GetCaps(IWMDMDevice* pDevice)
{
    HRESULT hr = S_OK;

    // Get all capabilities for audio and mime support.
    _WAVEFORMATEX* pAudioFormats;
    LPWSTR* pMimeFormats;
    UINT numAudioFormats = 0;
    UINT numMimeFormats = 0;
    hr = pDevice->GetFormatSupport(
        &pAudioFormats,
        &numAudioFormats,
        &pMimeFormats,
        &numMimeFormats);

    HANDLE_HR(hr, "Got audio and mime formats in GetCaps IWMDMDevice", "Couldn't get audio and mime formats in GetCaps IWMDMDevice");

    // Print out audio format data.
    if (numAudioFormats > 0)
    {
        / /TODO: Display a banner to precede the supported formats.
    }
    else
    {
        // TODO: Display a message indicating that no formats are supported.
    }
    for(int i = 0; i < numAudioFormats; i++)
    {
        // TODO: Display a configuration value.
        PrintWaveFormatGuid(pAudioFormats[i].wFormatTag);
        // TODO: Display a max channel value.
        // TODO: Display a max samples/second value.
        // TODO: Display the max bytes/second value.
        // TODO: Display the block alignment value.
        // TODo: Display the max bits/sample value.
    }

    // Print out MIME formats.
    if (numMimeFormats > 0)
        // TODO: Display a banner for the MIME format listing.
    else
        / /TODO: Display a message indicating that no MIME formats are supported.
    for(i = 0; i < numMimeFormats; i++)
    {
        // TODO: Display each individual MIME format.
    }

e_Exit:
    return;

}

Requirements

Header: Defined in mswmdm.h.

Library: mssachlp.lib

See Also