Selecting Input within DirectSound

Selecting Input within DirectSound

• SimonS_

  Hi,

  just wanted to tell you that what you want to do is described in this project

  http://www.codeproject.com/cs/media/directxcapture.asp

  But it's all done with functions made by the author so you will have to do some serious analysis of his sourcecode =)

  BTW, I'm trying to find the same info as you

  /Jonas

  
  

• Serene Seraph

  The way directX work is that you setup for the system a function to call
  (a callback function)

  It's not you who call that function but the system itself
  (when you ask him to enumerate)

  The system, not you, will look into each device on your PC

  and call that function repeatedly Not to make anything work but just to give you info

  It is very much the way the screen resolution setup work it ''enumerate''

  So for each device the system find installed in your pc

  the system call the function...since you know that you ''only''

  have to catch those call in a Table that you can access later

  In that table will be 3 device if the system found tree device and call your callback

  3 times...

  Exemple: you set up this call back in your code

  MyCallBack(Info){

  Table=Info;
  i++;

  }

  You call this

  EnumerateAllInputDevice(my call back is MyCallBack);

  The system call your call back 3 times

  You are left with a table of 3 entry each containing info to each device

  MyDevice->Setmyinfo(Table[0]);

  You choose one of the three to select your input device

  (all this is only a sample...not the real function in any way)

  Allmost all Hardward function work this way...

  Hope this help

  http://msdn.microsoft.com/library/default.asp url=/library/en-us/directx9_c/directsoundcaptureenumerate.asp

  
  

• m00gle

  From what I've been reading about DirectSoundCaptureEnumerate, it looks like:
  

  • It's an unmanaged function call
  • The managed equivalent is DevicesCollection().

  If I am right, then this isn't what I'm looking for. If I'm wrong, then I don't understand how DirectsoundCaptureEnumerate works.
  
  In the Win32 world, it looks like one would use calls to mixerOpen() and the like.
  
  Is there an mixerOpen() equivalent within DirectSound
  
  LGuy
  
  

• 112ilias

  
  You set up the call back function :

  http://msdn.microsoft.com/library/default.asp url=/library/en-us/directx9_c/DSEnumCallback.asp

  This will be call for each device
  and give you the ID of all the Input Device one call at a time
  You have to save those in a global table value

  lpGuid
  Address of the GUID that identifies the device being enumerated, or NULL for the

  primary device. This value can be passed to the DirectSoundCreate8 or

  DirectSoundCaptureCreate8 function to create a device object for that driver.

  You put one of those lpGuid entry in this:

  HRESULT DirectSoundCaptureCreate8(
  LPCGUID lpcGUID,
  LPDIRECTSOUNDCAPTURE8 * lplpDSC,
  LPUNKNOWN pUnkOuter
  );

  You will select the input device you want...
  (NULL is the default Capture device that you can set manually)

  
  According to what you tell me it's call DevicesCollection in managed code

  It's the same principle...in some form this collection
  will include entry for each input device

  You will need to find which is which in that collection
  And retreive the info for the input device you want to select
  then use some sort of DirectSoundCreateCaptureBuffer with the info

  I'm not good in Managed code but maybe others can help you

  It must go something like (just a far from it example...)

  DevicesCollection(0).Info = is the primary line
  DevicesCollection(1).Info = is the line 2
  DevicesCollection(2).Info = is the microphone line
  etc...

  
  you use that GUID in the Info to create your capture buffer
  Something like:

  DirectSoundCaptureCreate8(DeviceCollection(1).Info.GUID)

  Something of that kind...will select the input line you want to use

  Probably that in managed code it's a lot easier to use then in C++

  Hopefully others can explain to you how those collection work in managed code
  

  
  

• Musa34252

  I'm in the same situation as the originator of this thread.
  Can MS say lound and clear that it is impossible to enumerate & select an individual input (e.g. Microphone) when using DirectSound It is possible with DirectShow which is , as I understand, a layer above DirectSound - so how come it is not possible with DirectSound

  I need this for a C++ application that searches for an audio pattern on all possible computer inputs.

  Thanks

  
  

• parthsaha

  I looked at the DevicesCollection more closely. It appears to represent just the sound card and not individual inputs.
  
  I've come to the conclusion that managed DirectSound does not offer what I want to do. I was hoping that whatever was available in the Win32 world would be available in the managed DirectSound.
  
  Thanks for your help,
  LGuy
  
  
• Selecting Input within DirectSound