The other components in the figure are system-supplied.Īt the top left of the figure, the wave-rendering (or "wave-out") application interfaces to the WDM audio drivers through the waveOut Xxx functions, which are implemented in the user-mode WinMM system component, Winmm.dll. The boxes representing the wave miniport driver are darkened to indicate that these are vendor-supplied components.
The rendering components appear on the left side of the preceding figure, and the capture components appear on the right. The following figure shows the user-mode and kernel-mode components that a wave application uses to render or capture a digital audio stream consisting of wave PCM data. Graph building is transparent to the applications that use these software interfaces. For more information about DirectSound and the Windows Multimedia wave functions, see the Microsoft Windows SDK documentation.ĭirectSound and the Windows Multimedia wave functions are clients of the SysAudio system driver, which builds the audio filter graphs that process the wave and DirectSound streams. However, by emulating the behavior of older software and hardware, the waveOut Xxx functions sacrifice the 3-D sound effects and hardware acceleration that are now available through the DirectSound API. Beginning with Windows 98, the WDMAud system driver translates calls to these functions into commands to WDM audio drivers. The behavior of the waveOut Xxx and waveIn Xxx functions is based on the capabilities of legacy wave drivers and devices. Microsoft Windows Multimedia waveOut Xxx and waveIn Xxx functions
A wave stream is a digital-audio stream whose data format is described by a WAVEFORMATEX or WAVEFORMATEXTENSIBLE structure.Īn application can use either of the following software interfaces for wave rendering and capture: Application programs rely on a combination of user-mode and kernel-mode components to capture (input) and render (output) wave streams.
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