Re: [PATCH v2 0/6] MR4879: mfplat: Better implement MFCreateWaveFormatExFromMFMediaType with AAC media type.

[Nikolay Sivov (＠nsivov)]

Nikolay Sivov (@nsivov) commented about dlls/mfplat/mediatype.c:
>  if (!IsEqualGUID(&major, &MFMediaType_Audio))
>      return E_INVALIDARG;
>
> - if (!IsEqualGUID(&subtype, &MFAudioFormat_PCM) && !IsEqualGUID(&subtype, &MFAudioFormat_Float))
> - if (FAILED(hr = IMFMediaType_GetBlobSize(mediatype, &MF_MT_USER_DATA, &user_size)))
> {
> -
>    FIXME("Unsupported audio format %s.\n", debugstr_guid(&subtype));
> -
>    return E_NOTIMPL;
> -
>    if (!IsEqualGUID(&subtype, &MFAudioFormat_PCM) && !IsEqualGUID(&subtype, &MFAudioFormat_Float))
> -
>        return hr;
> -
>    user_size = 0;
> }

To check if attribute exists it's enough to use GetItem(key, NULL). Here it's fine of course, since you'll need user size anyway.