IAMDirectSound Interface

The IAMDirectSound interface provides access from Microsoft® DirectShow™ to Microsoft DirectX™ audio interfaces, such as IDirectSound and IDirectSoundBuffer. This enables you to play back the audio portions of DirectShow-compatible media files anywhere within the 3-D space of a DirectX application, making your applications much more absorbing and lifelike.

After you connect the media source file to a sound renderer on a filter graph, you can use DirectSound's functionality to position or manipulate the sound playback as needed. For more information on the relevant DirectSound interfaces and methods, see the DirectX SDK documentation. After you finish with an interface you obtained through IAMDirectSound, be sure to release it by calling the appropriate method. If you disconnect the sound renderer from the graph before releasing the interfaces, your application might fail.

The DSound Audio Renderer filter implements this interface.

Note Only the GetWindowFocus and SetWindowFocus methods are currently implemented for this interface.

When to Implement

This interface is implemented by the DSound Audio Renderer filter.

When to Use

The DSound Audio Renderer filter uses this interface; it is not intended for other uses.

Methods in Vtable Order

IUnknown methods	Description
QueryInterface	Returns pointers to supported interfaces.
AddRef	Increments the reference count.
Release	Decrements the reference count.

IAMDirectSound methods	Description
GetDirectSoundInterface	Retrieves a handle to the current sound device's IDirectSound interface. Not currently implemented.
GetPrimaryBufferInterface	Retrieves a handle to the current sound device's primary sound buffer. Not currently implemented.
GetSecondaryBufferInterface	Retrieves a handle to the current sound device's secondary sound buffer. Not currently implemented.
ReleaseDirectSoundInterface	Releases the current sound device's IDirectSound interface. Not currently implemented.
ReleasePrimaryBufferInterface	Releases the current sound device's primary sound buffer. Not currently implemented.
ReleaseSecondaryBufferInterface	Releases the current sound device's secondary sound buffer. Not currently implemented.
SetWindowFocus	Sets the window that will handle sound playback for the current media file.
GetWindowFocus	Retrieves the window that is handling sound playback for the current media file.

---

IAMDirectSound::GetDirectSoundInterface

IAMDirectSound Interface

Retrieves a handle to the current sound device's IDirectSound interface. Not currently implemented.

HRESULT IAMDirectSound::GetDirectSoundInterface(
  LPDIRECTSOUND *lplpds
  );

Parameters

lplpds

Address of a pointer to an IDirectSound interface that will point to the current sound device's interface.

Return Values

Returns one of the following values.

Value	Meaning
E_FAIL	No sound device is available.
E_INVALIDARG	The lplpds parameter is null.
E_NOTIMPL	DirectSound isn't installed.
NOERROR	The method succeeded.

---

IAMDirectSound::GetPrimaryBufferInterface

IAMDirectSound Interface

Retrieves a handle to the current sound device's primary sound buffer. Not currently implemented.

HRESULT IAMDirectSound::GetDirectSoundInterface(
  LPDIRECTSOUNDBUFFER *lplpdsb
  );

Parameters

lplpdsb

Address of a pointer to an IDirectSoundBuffer interface that will point to the current sound device's primary sound buffer.

Return Values

Returns one of the following values.

Value	Meaning
E_FAIL	No sound device is available.
E_INVALIDARG	The lplpdsb parameter is null.
E_NOTIMPL	DirectSound isn't installed.
NOERROR	The method succeeded.

---

IAMDirectSound::GetSecondaryBufferInterface

IAMDirectSound Interface

Retrieves a handle to the current sound device's secondary sound buffer. Not currently implemented.

HRESULT IAMDirectSound::GetSecondaryBufferInterface(
  LPDIRECTSOUNDBUFFER *lplpdsb
  );

Parameters

lplpdsb

Address of a pointer to an IDirectSoundBuffer interface. On exit, it will point to the current sound device's secondary sound buffer.

Return Values

Returns one of the following values.

Value	Meaning
E_FAIL	No sound device is available.
E_INVALIDARG	The lplpdsb parameter is null.
E_NOTIMPL	DirectSound isn't installed.
NOERROR	The method succeeded.

---

IAMDirectSound::GetWindowFocus

IAMDirectSound Interface

Retrieves the window that is handling sound playback for the current media file.

HRESULT IAMDirectSound::GetWindowFocus(
  HWND* hWnd,
  BOOL bMixingOnOrOff
  );

Parameters

hWnd

Handle to the sound playback window. If this value is null, the sound isn't associated with a window; note that Windows NT 4.0 does not currently support windowless sound playback.

bMixingOnOrOff

Value indicating whether to mix the sound (TRUE) or not (FALSE).

Return Values

Returns one of the following values.

Value	Meaning
E_FAIL	No sound device is available.
E_INVALIDARG	The hWnd argument is invalid.
E_NOTIMPL	DirectSound isn't installed.
NOERROR	The method succeeded.

---

IAMDirectSound::ReleaseDirectSoundInterface

IAMDirectSound Interface

Releases the current sound device's IDirectSound interface. Not currently implemented.

HRESULT IAMDirectSound::ReleaseDirectSoundInterface(
  LPDIRECTSOUND lpds
  );

Parameters

lpds

Pointer to the IDirectSound interface to release.

Return Values

Returns one of the following values.

Value	Meaning
E_FAIL	There are no references to the specified IDirectSound interface, so it can't be released.
E_INVALIDARG	The lpds parameter is null.
NOERROR	The method succeeded.

---

IAMDirectSound::ReleasePrimaryBufferInterface

IAMDirectSound Interface

Releases the current sound device's primary sound buffer. Not currently implemented.

HRESULT IAMDirectSound::ReleasePrimaryBufferInterface(
  LPDIRECTSOUNDBUFFER lpdsb
  );

Parameters

lpdsb

Pointer to the IDirectSoundBuffer interface to release.

Return Values

Returns one of the following values.

Value	Meaning
E_FAIL	There are no references to the specified IDirectSoundBuffer interface, so it can't be released.
E_INVALIDARG	The lpdsb parameter is null.
NOERROR	The method succeeded.

---

IAMDirectSound::ReleaseSecondaryBufferInterface

IAMDirectSound Interface

Releases the current sound device's secondary sound buffer. Not currently implemented.

HRESULT IAMDirectSound::ReleaseSecondaryBufferInterface(
  LPDIRECTSOUNDBUFFER lpdsb
  );

Parameters

lpdsb

Pointer to the IDirectSoundBuffer interface to release.

Return Values

Returns one of the following values.

Value	Meaning
E_FAIL	There are no references to the specified IDirectSoundBuffer interface, so it can't be released.
E_INVALIDARG	The lpdsb parameter is null.
NOERROR	The method succeeded.

---

IAMDirectSound::SetWindowFocus

IAMDirectSound Interface

Sets the window that will handle sound playback for the current media file.

HRESULT IAMDirectSound::SetWindowFocus(
  HWND hWnd,
  BOOL bMixingOnOrOff
  );

Parameters

hWnd

Handle to the sound playback window. If this value is null, the sound will not be associated with any window; note that Windows NT 4.0 does not currently support windowless sound playback.

bMixingOnOrOff

Value indicating whether to mix the sound (TRUE) or not (FALSE).

Return Values

Returns one of the following values.

Value	Meaning
E_FAIL	No sound device is available.
E_INVALIDARG	The hWnd argument is invalid.
E_NOTIMPL	DirectSound isn't installed.
NOERROR	The method succeeded.

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