[ADVANCED-DOTNET] Marshalling WM_MEDIA_TYPE

[Alex Ivanoff]

I am creating a wrapper for Windows media and having problems marshalling
WM_MEDIA_TYPE:
typedef struct _WMMediaType{
    GUID  majortype;
    GUID  subtype;
    BOOL  bFixedSizeSamples;
    BOOL  bTemporalCompression;
    ULONG  lSampleSize;
    GUID  formattype;
    IUnknown*  pUnk;
    ULONG  cbFormat;
    [size_is(cbFormat)] BYTE  *pbFormat;
} WM_MEDIA_TYPE;

The method signature is:
IWMMediaProps::GetMediaType(WM_MEDIA_TYPE * pType, DWORD * pcbType);

My question is: how to marshal WM_MEDIA_TYPE structure and pbFormat?