IAudioStreamVolume::GetAllVolumes Method

The GetAllVolumes method retrieves the volume levels for all the channels in the audio stream.

Syntax

public:
HRESULT GetAllVolumes(
         UINT32 dwCount,
         float *pfVolumes
)

Parameters

dwCount
Type: UINT32

[in]

The number of elements in the pfVolumes array. The dwCount parameter must equal the number of channels in the stream format. To get the number of channels, call the IAudioStreamVolume::GetChannelCount method.

pfVolumes
Type: float *

[out]

Pointer to an array of volume levels for the channels in the audio stream. This parameter points to a caller-allocated float array into which the method writes the volume levels for the individual channels. Volume levels are in the range 0.0 to 1.0.

Return value

Type: HRESULT

If the method succeeds, it returns S_OK. If it fails, possible return codes include, but are not limited to, the values shown in the following table.

Return codes

Return code	Description
E_INVALIDARG	Parameter dwCount does not equal the number of channels in the stream.
E_POINTER	Parameter pfVolumes is NULL.
AUDCLNT_E_DEVICE_INVALIDATED	The audio endpoint device has been unplugged, or the audio hardware or associated hardware resources have been reconfigured, disabled, removed, or otherwise made unavailable for use.
AUDCLNT_E_SERVICE_NOT_RUNNING	The Windows audio service is not running.

Refer to WASAPI error codes.

Remarks

Clients can call the IAudioStreamVolume::SetAllVolumes or IAudioStreamVolume::SetChannelVolume method to set the per-channel volume levels in an audio stream.

Requirements

Header: Declared in audioclient.h.

Library: Use mmdevapi.lib.