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

Remarks

Modifies the current pre-amplifier's amplification value (for stereo and mono sounds). The current value can be obtained through the Effects.PreAmplifierValueGet 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.PreAmplifierValueSet (

nPlayer as Integer,

fValue as Single,

nScaleType as enumVolumeScales

) as enumErrorCodes

[C++]

short control.Effects.PreAmplifierValueSet (

short nPlayer,

float fValue,

short nScaleType

);

Parameter

Description

nPlayer

Number representing the zero-based index of the involved player

fValue

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

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

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.