[wdmaudiodev] for help in implementation virtual audio driver

  • From: Weiji Zheng <weiji_zheng@xxxxxxxxxxxx>
  • To: wdmaudiodev@xxxxxxxxxxxxx
  • Date: Thu, 20 Jul 2006 12:49:08 +0800 (CST)

  I am developing one project, that is, PCM data is transfered into MSVAD by 
usr mode, and MSVAD then put these PCM data into another application based on 
DirectSound, such as Skype, that means MSVAD will be open simultaneously both 
the applications.
  Actaully, I encounter the same question as following: 

1. how can I get the handle of the MSVAD(Simple)? 
2. I tried to use IoRegisterDeviceInterface() in AddDevice() of MSVAD(Simple), 
and then in my user mode application I use SetupDiGetDeviceInterfaceDetail() 
and CreateFile() to get the handle of the MSVAD device. It seems that I can get 
the handle of the MSVAD(Simple), but the Graph Edit con not find any device 
about MSVAD, Do you have any idea about this? 
  Maybe the implementation in IRP_MAJOR_CREATE is one key.
  //dispatch function
extern "C"
    IN      PDEVICE_OBJECT  pDeviceObject,
    IN      PIRP            pIrp
 PIO_STACK_LOCATION IrpStack = IoGetCurrentIrpStackLocation(pIrp);
 DPF(D_TERSE, ("[enter PCP_Create]"));
 DbgPrint("the Flags is 0x%x\n", pIrp->Flags);
 DbgPrint("the RequestorMode is 0x%x\n", pIrp->RequestorMode);
   if(pIrp->RequestorMode == 0x1) //my own application
 {// Complete successfully
  pIrp->IoStatus.Status = STATUS_SUCCESS;
  pIrp->IoStatus.Information = 0;
  IoCompleteRequest(pIrp, IO_NO_INCREMENT);
 else //Graph Edit
   // Pass the IRPs on to PortCls
   ntStatus = PcDispatchIrp( pDeviceObject, pIrp );
   DbgPrint("success to open device\n");
   DbgPrint("fail to open device\n");
  return ntStatus;
  But when I run own application(not Graph Edit), the system crash!
  so would you please give me some advice.
  thanks for any help.
  best regards
  --weiji zheng


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