Detect emptiness of DVD-RAM media on Windows 7 x64

I'm trying to detect if a DVD-RAM media is empty or not, with C++ on Windows. The simplest choice is to use IMAPI (version 2) - boilerplate code omitted:

IMAPI_FORMAT2_DATA_MEDIA_STATE state;
HRESULT hr;

// ..开发者_运维知识库. Initialize an MsftDiscFormat2Data COM object and put recorder

hr = format->get_CurrentMediaStatus( &state );
// ... Verify returned status ...    
return (state & IMAPI_FORMAT2_DATA_MEDIA_STATE_BLANK);

This code usually works perfectly. However, with DVD-RAM it gives the wrong results: the only flag enabled in the returned state is IMAPI_FORMAT2_DATA_MEDIA_STATE_OVERWRITE_ONLY ( = 0x1). On Windows Vista 32 bit it works as expected.

Does anyone knows the reason for this result? Is there any workaround?

You can use the method IDiscFormat2::get_MediaHeuristicallyBlank from IDiscFormat2 interface.

It will attempt to determine if the media is blank using heuristics (mainly for DVD+RW and DVD-RAM media).

VARIANT_BOOL vbBlank;

hr = format->get_MediaHeuristicallyBlank(&vbBlank);

if (VARIANT_TRUE == vbBlank)
   Log("The media is blank.");

In order to determine if the current media is reported as physically blank by the drive you can use IDiscFormat2::get_MediaPhysicallyBlank method.

As for the reasons of the different behavior between Windows7 x64 and Windows Vista x86, it could be because IMAPIv2 versions may be different on those systems. You may want to update your Vista machine with the latest Image Mastering API v2.0 update package to get the same results on each system.