COM Objects > Effects object > Methods > Effects.PreAmplifierValueGet method

Remarks

Obtains the current pre-amplifier's amplification value (for stereo and mono sounds). The current value can be modified through the Effects.PreAmplifierValueSet method.

Pre-amplification is applied only if enabled through a previous call to the Effects.PreAmplifierEnable method.

See the How to apply special effects to a playing sound section for further details.

Syntax

[Visual Basic]

control.Effects.PreAmplifierValueGet (

nPlayer as Integer,

fValue as Single,

nScaleType as enumVolumeScales

) as enumErrorCodes

[C++]

short control.Effects.PreAmplifierValueGet (

short nPlayer,

float *fValue,

short nScaleType

);

Parameter

Description

nPlayer

Number representing the zero-based index of the involved player

fValue

Reference that, on return from the method call, will contain the amplification value expressed in the unit specified by the nScaleType parameter.

nScaleType

The amplification scaling type.

Supported values are the following:

Mnemonic constant

Value

Meaning

SCALE_LINEAR

Returned amplification, expressed in percentage, is based upon a linear scale:

- value 0.0 mutes the playing sound

- values higher than 0.0 and smaller than 100.0 attenuate the playing sound

- value 100.0 keeps sound level unchanged

- values higher than 100.0 amplify the playing sound

SCALE_LOG

Returned amplification, expressed in dB, is based upon a logarithmic scale:

- value -100.0 mutes the playing sound

- values higher than -100.0 and smaller than 0.0 attenuate the playing sound

- value 0.0 keeps sound level unchanged

- values higher than 0.0 amplify the playing sound

The actual applied formula for converting a linear volume into a logarithmic volume is the following:

VolumeInDB = 20 * log10 (VolumeLinear/100)

The C syntax for converting a logarithmic volume into a linear volume is the following:

VolumeLinear = 100 * pow (10, VolumeInDB/20);

Return value

Value	Meaning

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