2.2.2 SAE_VolumeChange

When sent from the client to the server, the SAE_VolumeChange message indicates a request to set the volume setting for a specific dataflow (as defined in [MSDN-EDataFlow]) to the specified level. When sent from the server to the client, it indicates that the volume setting for a specific dataflow has been changed to the specified level.


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eEvent (0x00000002)

eDataFlow

lVolume

fMuted

eEvent(4 bytes):  A 32-bit unsigned integer that specifies message type.  The value for SAE_VolumeChange is 0x00000002.

eDataFlow (4 bytes):   A 32-bit unsigned integer that specifies the specific volume setting. The eDataFlow field MUST be one of the following values.

Value

Meaning

eRender

0x00000000

The specified volume level affects the render or playback volume.

eCapture

0x00000001

The specified volume level affects the capture or recording volume.

lVolume (4 bytes):   A 32-bit float. The volume level is normalized to the range of 0.0 to 1.0, where 0.0 is the minimum level and 1.0 is the maximum level. Within this range, the relationship of the normalized volume level to the attenuation of signal amplitude is described by a nonlinear, audio-tapered curve.<1>

fMuted (4 bytes):   A 32-bit unsigned integer that specifies if the dataflow (as defined in [MSDN-EDataFlow]) is turned off or disabled.

Value

Meaning

FALSE0x00000000

The specified dataflow is not disabled.

TRUE0x00000001

The specified dataflow is disabled.