wasapi: add a new volume property and implement volume/mute using ISimpleAudioVolume

Submitted by Christoph Reiter (lazka)

Link to original bug (#796386)

Description

Created attachment 372385
wasapi: add a new volume property and implement volume/mute using ISimpleAudioVolume

Implement mute/volume getters setters using ISimpleAudioVolume. This allows setting
those properties without delay and volume/mute changes will show up in sndvol.exe.

ISimpleAudioVolume only works in shared mode, so keep the old way of muting around
by setting the buffer to silent, to not break any existing code. Volume changes in
exclusive mode have no effect atm. Also missing is event handling of external
volume/mute changes through IAudioSessionEvents.

Patch 372385, "wasapi: add a new volume property and implement volume/mute using ISimpleAudioVolume":
0001-wasapi-add-a-new-volume-property-and-implement-volum.patch

Version: 1.14.0