Buffer Position and Velocity

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[The feature associated with this page, DirectSound, is a legacy feature. It has been superseded by WASAPI and Audio Graphs. Media Casting have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use Media Casting instead of DirectSound, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

As a sound source moves, it is up to the application to specify values for its position and velocity.

Position is measured in distance units along each of the three axes, relative to either world space or the listener, depending on the processing mode.

Velocity is measured in distance units per second along each of the three axes of a vector. By default, distance units are meters. Velocity is used by DirectSound only to calculate the effects of Doppler shift.