Methods > IO devices and system mixers

Remarks

Obtains the volume from a specific component of the given mixer.

The returned volume can be modified using the MixerVolumeSet method.

The number of mixers currently installed on the system can be retrieved using the MixerGetCount method. A friendly description of the mixer can be retrieved using the MixerGetDesc method.

IMPORTANT NOTE ABOUT THE WINDOWS VERSION: This method is only intended for usage when the operating system is Windows XP or older versions; for Windows Vista and higher versions it's recommended using methods exposed by the CoreAudioDevicesMan class.

Syntax

[Visual Basic]

Public Function MixerVolumeGet (

nIndex as Int16,

nComponentType as enumComponentTypes,

ByRef nValue as Int32

) as enumErrorCodes

[C#]

public enumErrorCodes MixerVolumeGet (

Int16 nIndex,

enumComponentTypes nComponentType,

ref Int32 nValue

);

[C++]

public: enumErrorCodes MixerVolumeGet (

Int16 nIndex,

enumComponentTypes nComponentType,

Int32 __gc *nValue

);

Parameter

Description

nIndex

Number representing the zero-based index of the mixer whose volume must be retrieved.

nComponentType

The type of mixer's component.

Supported values are the following:

Mnemonic constant	Value	Meaning
COMPONENTTYPE_DST_DIGITAL	0	Audio line is a digital destination (for example, digital input to a DAT or CD audio device).
COMPONENTTYPE_DST_LINE	1	Audio line is a line level destination (for example, line level input from a CD audio device) that will be the final recording source for the analog-to-digital converter (ADC). Because most audio cards for personal computers provide some sort of gain for the recording audio source line, the mixer device will use the COMPONENTTYPE_DST_WAVEIN type.
COMPONENTTYPE_DST_MONITOR	2	Audio line is a destination used for a monitor.
COMPONENTTYPE_DST_SPEAKERS	3	This is usually identified on the user interface as "Master volume". Audio line is an adjustable (gain and/or attenuation) destination intended to drive speakers. This is the typical component type for the audio output of audio cards for personal computers.
COMPONENTTYPE_DST_HEADPHONES	4	Audio line is an adjustable (gain and/or attenuation) destination intended to drive headphones. Most audio cards use the same audio destination line for speakers and headphones, in which case the mixer device simply uses the COMPONENTTYPE_DST_SPEAKERS type.
COMPONENTTYPE_DST_TELEPHONE	5	Audio line is a destination that will be routed to a telephone line.
COMPONENTTYPE_DST_WAVEIN	6	Audio line is a destination that will be the final recording source for the waveform-audio input (ADC). This line typically provides some sort of gain or attenuation. This is the typical component type for the recording line of most audio cards for personal computers.
COMPONENTTYPE_DST_VOICEIN	7	Audio line is a destination that will be the final recording source for voice input. This component type is exactly like COMPONENTTYPE_DST_WAVEIN but is intended specifically for settings used during voice recording/recognition. Support for this line is optional for a mixer device. Many mixer devices provide only COMPONENTTYPE_DST_WAVEIN.
COMPONENTTYPE_SRC_DIGITAL	8	Audio line is a digital source (for example, digital output from a DAT or audio CD).
COMPONENTTYPE_SRC_LINE	9	Audio line is a line-level source (for example, line-level input from an external stereo) that can be used as an optional recording source. Because most audio cards for personal computers provide some sort of gain for the recording source line, the mixer device will use the COMPONENTTYPE_SRC_AUXILIARY type.
COMPONENTTYPE_SRC_MICROPHONE	10	This is usually identified on the user interface as "Microphone". Audio line is a microphone recording source. Most audio cards for personal computers provide at least two types of recording sources: an auxiliary audio line and microphone input. A microphone audio line typically provides some sort of gain. Audio cards that use a single input for use with a microphone or auxiliary audio line should use the COMPONENTTYPE_SRC_MICROPHONE component type.
COMPONENTTYPE_SRC_SYNTHESIZER	11	Audio line is a source originating from the output of an internal synthesizer. Most audio cards for personal computers provide some sort of MIDI synthesizer.
COMPONENTTYPE_SRC_COMPACTDISC	12	Audio line is a source originating from the output of an internal audio CD. This component type is provided for audio cards that provide an audio source line intended to be connected to an audio CD (or CD-ROM playing an audio CD).
COMPONENTTYPE_SRC_TELEPHONE	13	Audio line is a source originating from an incoming telephone line.
COMPONENTTYPE_SRC_PCSPEAKER	14	Audio line is a source originating from personal computer speaker. Several audio cards for personal computers provide the ability to mix what would typically be played on the internal speaker with the output of an audio card. Some audio cards support the ability to use this output as a recording source.
COMPONENTTYPE_SRC_WAVEOUT	15	This is usually identified on the user interface as "Wave volume". Audio line is a source originating from the waveform-audio output digital-to-analog converter (DAC). Most audio cards for personal computers provide this component type as a source to the COMPONENTTYPE_DST_SPEAKERS destination. Some cards also allow this source to be routed to the COMPONENTTYPE_DST_WAVEIN destination.
COMPONENTTYPE_SRC_AUXILIARY	16	Audio line is a source originating from the auxiliary audio line. This line type is intended as a source with gain or attenuation that can be routed to the COMPONENTTYPE_DST_SPEAKERS destination and/or recorded from the COMPONENTTYPE_DST_WAVEIN destination.
COMPONENTTYPE_SRC_ANALOG	17	Audio line is an analog source (for example, analog output from a video-cassette tape).

nValue

Reference that, on return from the method call, will contain the current volume in the range from 0 to 100

Return value

Value	Meaning

Negative value	An error occurred (see the LastError property for further error details)
enumErrorCodes.ERR_NOERROR (0)	The method call was successful