I have a section of code that initializes a direct sound capture object then buffer and then a notify object for that buffer: --------------------------- [All of this works] if(FAILED(pdsRXOb->CreateCaptureBuffer(&dsRXbd, &pdsRXBufOb, NULL))) // Create the capture buffer { return FALSE; } dsRXBufCaps.dwSize = sizeof(DSCBCAPS); // Get the capture buffer capabilities if(FAILED(pdsRXBufOb->GetCaps(&dsRXBufCaps))) { return FALSE; } // Create Notification interface for the capture buffer if(FAILED(pdsRXBufOb->QueryInterface(IID_IDirectSoundNotify, (void **)&pdsRXNotifyOb))) { return(FALSE); } ---------------------------------------------- It works fine. At least it compiles and executes. However, then I initialize a direct sound object, a secondary buffer and then try to place a notify object on that buffer. The notification object fails when executed. ---------------------------------------------- // Create the DirectSound buffer [This works] if(FAILED(pdsTXOb->CreateSoundBuffer(&dsTXbd, &pdsTXSecBufOb, NULL))) { return(FALSE); } // Create Notification interface for the send buffer [FAILS!!] if(FAILED(pdsTXSecBufOb->QueryInterface(IID_IDirectSoundNotify, (void **)&pdsTXNotifyOb))) { return(FALSE); } ----------------------------------------- Any ideas why I can''t create a notify object on the send buffer? Brian Reinhold

The error return value is "E_NOINTERFACE" but that seems hard to believe given that the capture buffer works, the computer (1 year old Gateway) and soundcard (Soundblaster Live) are modern.

I tried using the outdated initialization method on the buffer but that gives "already initialized" so that obviously is not a solution.

It''s hard to know where to go from here!

I wanted to put the receive and send activities in a single high priority thread using a WaitForMulipleEvents() function to handle the two actions.

Does it make any sense that the interface would be available for the capture but not the play option? If anything, I would assume the reverse!

Not first creating the capture notify object doesn''t change things either!



Brian Reinhold

Dave, it didn''t work. Same error...no interface. How could that be? I thought the primary purpose of having the notify event thing was for streaming playback. I don''t even know where to turn.


Brian Reinhold

That step of querying the DirectSoundBuffer interface to get the DirectSoundBuffer8 interface I have not done.

I have just created the Direct Sound object,
and from that created a DirectSoundBuffer object.

Wonder what the GUID idnetifier is called?

Brian

I still get the same error, even though I can query the directsoundbuffer interface to get the ''8'' version. But I can''t query the ''8'' version to get the notify object.

I used DirectSoundCreate8 on the ''8'' version of the direct sound object. Maybe I should keep it at no ''8''?

This is crazy. I wish I could see an example, but the SDK doesn''t have one for directsound...just directsoundcapture. At least that which I can find!

Brian

Dave,

If I add the flag "DSBCAPS_CTRLPOSITIONNOTIFY" in the DSBCAPS structure in my above code when creating the DirectSound object, then the notify interface is able to be created as written above, without all the ''8'' options. Why I need to do this for the DirectSound object and NOT the DirectSoundCapture object is something which I don''t understand.

Whether the notify event action will work, on the other hand, I have not tried. Now at least I will be able to proceed.

It is quite frustrating and it cost me a whole day! Thanks for your help. I DO wish there was more information somewhere on DirectSound and subsets. There is certainly PLENTY on DirectX in the graphics part!

Brian Reinhold