Microsoft DirectX 9.0

Volume Envelope Effect

The Volume Envelope effect sets the volume on an audio stream.

Class ID (CLSID): {036A9790-C153-11D2-9EF7-006008039E37}

CLSID Variable Name: CLSID_AudMixer


Property Type Default Description
Vol double 1.0 Volume, as a percentage of the authored volume. You can produce audio fades by varying this property value over time.


Each object in a timeline can have at most one volume envelope effect. In a composition or a group, the volume envelope is applied first, before any other audio effects, regardless of its priority. In a source or a track, the volume effect is applied according to its priority.