Microsoft DirectX 9.0 SDK Update (October 2004)

Standard Audiopaths

If your application does not play exclusively on audiopaths created from audiopath configuration objects, you must create one or more standard audiopaths.

Standard audiopaths are identified by the values passed in the dwType parameter of IDirectMusicPerformance8::CreateStandardAudioPath or in the dwDefaultPathType parameter of IDirectMusicPerformance8::InitAudio.

The audiopaths defined by DirectMusic manage the flow of synthesizer output through combinations of standard buffers, some of which have effect DMOs attached to them. The following table shows the standard audiopaths and which standard buffers they contain. Shared buffers can be used by more than one audiopath.

Audiopath type	Standard buffers	Buffer shared?
DMUS_APATH_DYNAMIC_3D	3-D Dry	No
DMUS_APATH_DYNAMIC_MONO	Mono	No
DMUS_APATH_DYNAMIC_STEREO	Stereo	No
DMUS_APATH_SHARED_STEREOPLUSREVERB	Music Reverb	Yes Yes

Characteristics of the standard buffers are shown in the following table, where the Capabilities column lists values returned in the dwFlags member of the DSBCAPS structure passed to IDirectSoundBuffer8::GetCaps. The last column shows interfaces that can be obtained from the buffer object. In addition, applications can add effects to buffers by using IDirectSoundBuffer8::SetFX, making other interfaces available. For more information on obtaining interfaces, see Retrieving Objects from an Audiopath.

Standard buffer	Description	Capabilities	Interfaces
3-D Dry	Mono 3-D buffer	DSBCAPS_CTRL3D DSBCAPS_CTRLFREQUENCY DSBCAPS_CTRLFX DSBCAPS_CTRLVOLUME DSBCAPS_GLOBALFOCUS DSBCAPS_MUTE3DATMAXDISTANCE	IDirectSound3DBuffer8 IDirectSoundBuffer8 IDirectSound3DBuffer8
Mono	Mono buffer with no effects	DSBCAPS_CTRLFREQUENCY DSBCAPS_CTRLFX DSBCAPS_CTRLPAN DSBCAPS_CTRLVOLUME DSBCAPS_GLOBALFOCUS	IDirectSoundBuffer8
Music	Stereo buffer used with Reverb	DSBCAPS_CTRLFX DSBCAPS_CTRLPAN DSBCAPS_CTRLVOLUME DSBCAPS_GLOBALFOCUS	IDirectSoundBuffer8
Reverb	Stereo buffer with music reverberation effect	DSBCAPS_CTRLFX DSBCAPS_CTRLPAN DSBCAPS_CTRLVOLUME DSBCAPS_GLOBALFOCUS	IDirectSoundFXWavesReverb8 IDirectSoundBuffer8
Stereo	Stereo buffer with no effects	DSBCAPS_CTRLFREQUENCY, DSBCAPS_CTRLFX, DSBCAPS_CTRLPAN DSBCAPS_CTRLVOLUME DSBCAPS_GLOBALFOCUS	IDirectSoundBuffer8

More information about the standard audiopaths is available in the following topics: