Methods > Players and stream mixers > PreAmplifierSetSpeakerValue method

Remarks

Modifies the preamplifier's amplification value related to a specific speaker (only for multi-channel songs like 5.1 or 7.1). The current value can be obtained through the PreAmplifierGetSpeakerValue method.

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

Syntax

[Visual Basic]

control.PreAmplifierSetSpeakerValue (

nPlayer as Integer,

nSpeaker as enumSpeakers

fValue as Single,

nScaleType as enumVolumeScales

) as enumSoundDirections

[C++]

short control.PreAmplifierSetSpeakerValue (

short nPlayer,

short nSpeaker,

float fValue,

short nScaleType

);

Parameter

Description

nPlayer

Number representing the zero-based index of the involved player

nSpeaker

The output speaker assigned to the given player.

Supported values are the following:

Mnemonic value	Numeric value	Meaning
SPEAKER_FRONT	0	Front speakers (Stereo)
SPEAKER_REAR	1	Rear speakers (Stereo)
SPEAKER_CENTER_LFE	2	Center speakers (Stereo)
SPEAKER_REAR_CENTER	3	Rear center speakers (Stereo)
SPEAKER_FRONT_LEFT	4	Front-left speaker (Mono)
SPEAKER_FRONT_RIGHT	5	Front-right speaker (Mono)
SPEAKER_REAR_LEFT	6	Rear-left speaker (Mono)
SPEAKER_REAR_RIGHT	7	Rear-right speaker (Mono)
SPEAKER_CENTER	8	Center speaker (Mono)
SPEAKER_LFE	9	LFE or Subwoofer speaker (Mono)
SPEAKER_REAR_CENTER_LEFT	10	Rear Center Left speaker (Mono)
SPEAKER_REAR_CENTER_RIGHT	11	Rear Center Right speaker (Mono)

Below you can see the positioning of the Stereo speakers on a wide 7.1 configuration (the reported blue numbers corresponds to the Numeric value of the parameter)

amp3dj_i00006c

and below you can see the positioning of the Mono speakers on the same wide 7.1 configuration

amp3dj_i00006d

fValue

The new 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.